OPA2830IDR

Burr Brown Products from Texas Instruments OPA2830 SBOS309C – AUGUST 2004 – REVISED MARCH 2006 Dual, Low-Power, Single-Supply, Wideband OPERATIONAL AMPLIFIER FEATURES • • • HIGH BANDWIDTH: 230MHz (G = +1), 100MHz (G = +2) LOW SUPPLY CURRENT: 7.8mA (VS = +5V) FLEXIBLE SUPPLY RANGE: ±1.5V to ±5.5V Dual Supply +3V to +11V Single Supply INPUT RANGE INCLUDES GROUND ON SINGLE SUPPLY 4.82VPP OUTPUT SWING ON +5V SUPPLY HIGH SLEW RATE: 500V/µs LOW INPUT VOLTAGE NOISE: 9.2nV/√Hz AVAILABLE IN AN MSOP-8 PACKAGE DESCRIPTION The OPA2830 is a dual, low-power, single-supply, wideband, voltage-feedback amplifier designed to operate on a single +3V or +5V supply. Operation on ±5V or +10V supplies is also supported. The input range extends below ground and to within 1.8V of the positive supply. Using complementary common-emitter outputs provides an output swing to within 25mV of ground and +VS while driving 150Ω. High output drive current (75mA) and low differential gain and phase errors also make it ideal for single-supply consumer video products. Low distortion operation is ensured by the high gain bandwidth product (100MHz) and slew rate (500V/µs), making the OPA2830 an ideal input buffer stage to 3V and 5V CMOS Analog-to-Digital Converters (ADCs). Unlike earlier low-power, single-supply amplifiers, distortion performance improves as the signal swing is decreased. A low 9.2nV/√Hz input voltage noise supports wide dynamic range operation. The OPA2830 is available in an industry-standard SO-8 package. The OPA2830 is also available in a small MSOP-8 package. For fixed-gain and line driver applications, consider the OPA2832. • • • • • • • • • • • • APPLICATIONS SINGLE-SUPPLY ADC INPUT BUFFERS SINGLE-SUPPLY VIDEO LINE DRIVERS CCD IMAGING CHANNELS LOW-POWER ULTRASOUND PLL INTEGRATORS PORTABLE CONSUMER ELECTRONICS LOW-POWER ACTIVE FILTERS 150pF +5V 0.1µF 238Ω 506Ω 1/2 OPA2830 RELATED PRODUCTS DESCRIPTION Rail-to-Rail Rail-to-Rail Fixed-Gain General-Purpose (1800V/µs slew rate) Low-Noise, High DC Precision SINGLES OPA830 OPA832 OPA690 OPA820 DUALS — OPA2832 OPA2690 OPA2822 TRIPLES — OPA3832 OPA3690 — QUADS OPA4830 — — OPA4820 +5V 238Ω 5kΩ 100pF 750Ω VI 2.5V BUF602 1500Ω 750Ω 238Ω 100pF 1/2 OPA2830 VO 0.1µF 5kΩ 0.1µF 238Ω 506Ω 150pF Single-Supply, Differential, 2nd-Order, 5MHz, Low-Pass Sallen-Key Filter Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2004–2006, Texas Instruments Incorporated OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. ORDERING INFORMATION (1) PACKAGE DESIGNATOR D DGK SPECIFIED TEMPERATURE RANGE –40°C to +85°C –40°C to +85°C PACKAGE MARKING OPA2830 A59 ORDERING NUMBER OPA2830ID OPA2830IDR OPA2830IDGKT OPA2830IDGKR TRANSPORT MEDIA, QUANTITY Rails, 100 Tape and Reel, 2500 Tape and Reel, 250 Tape and Reel, 2500 PRODUCT OPA2830 OPA2830 (1) PACKAGE-LEAD SO-8 Surface-Mount MSOP-8 For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI web site at www.ti.com. ABSOLUTE MAXIMUM RATINGS (1) Power Supply Internal Power Dissipation Differential Input Voltage Input Voltage Range Storage Temperature Range: D, DGK Lead Temperature (soldering, 10s) Junction Temperature (TJ) ESD Rating: Human Body Model (HBM) Charge Device Model (CDM) Machine Model (MM) (1) 2000V 1000V 200V 11VDC See Thermal Characteristics ±2.5V –0.5V to +VS + 0.3V –40°C to +125°C +300°C +150°C Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those specified is not supported. PIN CONFIGURATIONS Top View SO, MSOP Output 1 − Input 1 1 2 3 4 8 7 6 5 +VS Output 2 − Input 2 +Input 2 +Input 1 − VS 2 Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 ELECTRICAL CHARACTERISTICS: VS = ±5V Boldface limits are tested at +25°C. At TA = +25°C, G = +2V/V, RF = 750Ω, and RL = 150Ω to GND, unless otherwise noted (see Figure 70). OPA2830ID, IDGK TYP PARAMETER AC PERFORMANCE (see Figure 70) Small-Signal Bandwidth G = +1, VO ≤ 0.2VPP G = +2, VO ≤ 0.2VPP G = +5, VO ≤ 0.2VPP G = +10, VO ≤ 0.2VPP Gain Bandwidth Product Peaking at a Gain of +1 Slew Rate Rise Time Fall Time Settling Time to 0.1% Harmonic Distortion 2nd-Harmonic G ≥ +10 VO ≤ 0.2VPP G = +2, 2V Step 0.5V Step 0.5V Step G = +2, 1V Step VO = 2VPP, f = 5MHz RL = 150Ω RL ≥ 500Ω 3rd-Harmonic RL = 150Ω RL ≥ 500Ω Input Voltage Noise Input Current Noise NTSC Differential Gain NTSC Differential Phase DC PERFORMANCE (4) Open-Loop Voltage Gain Input Offset Voltage Average Offset Voltage Drift Input Bias Current Input Bias Current Drift Input Offset Current Input Offset Current Drift INPUT Negative Input Voltage Positive Input Voltage Common-Mode Rejection Ratio (CMRR) Input Impedance Differential Mode Common-Mode OUTPUT Output Voltage Swing G = +2, RL = 1kΩ to GND G = +2, RL = 150Ω to GND Current Output, Sinking and Sourcing Short-Circuit Current Closed-Loop Output Impedance Output Shorted to Ground G = +2, f ≤ 100kHz ±4.88 ±4.64 ±82 150 0.06 ±4.86 ±4.60 ±63 ±4.85 ±4.58 ±58 ±4.84 ±4.56 ±53 V V mA mA Ω min min min typ typ A A A C C 10 | | 2.1 400 | | 1.2 kΩ | | pF kΩ | | pF typ typ C C Input-Referred –5.5 3.2 80 –5.4 3.1 76 –5.3 3.0 74 –5.2 2.9 71 V V dB max min min A A A VCM = 2.0V ±0.2 — ±1.1 VCM = 2.0V RL = 150Ω 74 ±1.5 — +5 +10 66 ±7.5 65 ±8.7 ±27 +12 ±44 ±1.3 ±5 64 ±9.3 ±27 +13 ±46 ±1.5 ±6 dB mV µV/°C µA nA/°C µA nA/°C min max max max max max max A A B A B A B f > 1MHz f > 1MHz –62 –66 –59 –77 9.5 3.7 0.07 0.17 –55 –58 –50 –65 10.6 4.8 –53 –57 –49 –62 11.1 5.3 –52 –56 –48 –55 11.6 5.8 dBc dBc dBc dBc nV/√Hz pA/√Hz % ° min min min min max max typ typ B B B B B B C C 290 105 22 10 100 4 560 3.4 3.6 43 275 5.9 6.0 64 265 5.95 6.05 66 255 6.0 6.1 67 66 16 8 80 64 14 7 77 61 13 6 75 MHz MHz MHz MHz MHz dB V/µs ns ns ns typ min min min min typ min max max max C B B B B C B B B B CONDITIONS +25°C MIN/MAX OVER TEMPERATURE +25°C (1) 0°C to +70°C (2) –40°C to +85°C (2) UNITS MIN/ MAX TEST LEVEL (3) (1) (2) (3) (4) Junction temperature = ambient for +25°C specifications. Junction temperature = ambient at low temperature limits; junction temperature = ambient +18°C at high temperature limit for over temperature specifications. Test levels: (A) 100% tested at +25°C. Over temperature limits by characterization and simulation. (B) Limits set by characterization and simulation. (C) Typical value only for information. Current is considered positive out of pin. Submit Documentation Feedback 3 OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 ELECTRICAL CHARACTERISTICS: VS = ±5V (continued) Boldface limits are tested at +25°C. At TA = +25°C, G = +2V/V, RF = 750Ω, and RL = 150Ω to GND, unless otherwise noted (see Figure 70). OPA2830ID, IDGK TYP PARAMETER POWER SUPPLY Minimum Operating Voltage Maximum Operating Voltage Maximum Quiescent Current Minimum Quiescent Current Power-Supply Rejection Ratio (–PSRR) THERMAL CHARACTERISTICS Specification: ID, IDGK Thermal Resistance, θJA D DGK SO-8 MSOP-8 125 150 °C/W °C/W typ typ C C –40 to +85 °C typ C VS = ±5V, Both Channels VS = ±5V, Both Channels Input-Referred 8.5 8.5 66 ±1.4 ±5.5 9.5 8.0 61 ±5.5 10.7 7.2 60 ±5.5 11.9 6.6 59 V V mA mA dB typ max max min min C A A A A CONDITIONS +25°C MIN/MAX OVER TEMPERATURE +25°C (1) 0°C to +70°C (2) –40°C to +85°C (2) UNITS MIN/ MAX TEST LEVEL (3) 4 Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 ELECTRICAL CHARACTERISTICS: VS = +5V Boldface limits are tested at +25°C. At TA = +25°C, G = +2V/V, RF = 750Ω, and RL = 150Ω to VS/2, unless otherwise noted (see Figure 72). OPA2830ID, IDGK TYP PARAMETER AC PERFORMANCE (see Figure 72) Small-Signal Bandwidth G = +1, VO ≤ 0.2VPP G = +2, VO ≤ 0.2VPP G = +5, VO ≤ 0.2VPP G = +10, VO ≤ 0.2VPP Gain-Bandwidth Product Peaking at a Gain of +1 Slew Rate Rise Time Fall Time Settling Time to 0.1% Harmonic Distortion 2nd-Harmonic G ≥ +10 VO ≤ 0.2VPP G = +2, 2V Step 0.5V Step 0.5V Step G = +2, 1V Step VO = 2VPP, f = 5MHz RL = 150Ω RL ≥ 500Ω 3rd-Harmonic RL = 150Ω RL ≥ 500Ω Input Voltage Noise Input Current Noise NTSC Differential Gain NTSC Differential Phase DC PERFORMANCE (4) Open-Loop Voltage Gain Input Offset Voltage Average Offset Voltage Drift Input Bias Current Input Bias Current Drift Input Offset Current Input Offset Current Drift INPUT Least Positive Input Voltage Most Positive Input Voltage Common-Mode Rejection Ratio (CMRR) Input Impedance, Differential Mode Common-Mode OUTPUT Least Positive Output Voltage G = +5, RL = 1kΩ to 2.5V G = +5, RL = 150Ω to 2.5V Most Positive Output Voltage G = +5, RL = 1kΩ to 2.5V G = +5, RL = 150Ω to 2.5V Current Output, Sinking and Sourcing Short-Circuit Output Current Output Shorted to Either Supply 0.09 0.21 4.91 4.78 ±75 140 0.11 0.24 4.89 4.75 ±58 0.12 0.25 4.88 4.73 ±53 0.13 0.26 4.87 4.72 ±50 V V V V mA mA max max min min min typ A A A A A C Input-Referred –0.5 3.2 80 10 | | 2.1 400 | | 1.2 –0.4 3.1 76 –0.3 3.0 74 –0.2 2.9 71 V V dB kΩ | | pF kΩ | | pF max min min typ typ A A A C C VCM = 2.5V ±0.2 — ±0.9 VCM = 2.5V RL = 150Ω 72 ±0.5 — +5 +10 66 ±5.5 65 ±6.5 ±22 +12 ±44 ±1.1 ±5 64 ±7.0 ±22 +13 ±46 ±1.3 ±6 dB mV µV/°C µA nA/°C µA nA/°C min max max max max max max A A B A B A B f > 1MHz f > 1MHz –58 –62 –58 –84 9.2 3.5 0.075 0.087 –52 –56 –50 –65 10.3 4.6 –51 –55 –49 –62 10.8 5.1 –50 –54 –48 –60 11.3 5.6 dBc dBc dBc dBc nV/√Hz pA/√Hz % ° min min min min max max typ typ B B B B B B C C 230 100 21 10 100 4 500 3.4 3.4 44 270 5.8 5.8 65 260 5.9 5.9 67 250 6.0 6.0 68 70 15 7 75 68 14 6 65 66 13 5 59 MHz MHz MHz MHz MHz dB V/µs ns ns ns typ min min min min typ min max max max C B B B B C B B B B CONDITIONS +25°C MIN/MAX OVER TEMPERATURE +25°C (1) 0°C to +70°C (2) –40°C to +85°C (2) UNITS MIN/ MAX TEST LEVEL (3) (1) (2) (3) (4) Junction temperature = ambient for +25°C specifications. Junction temperature = ambient at low temperature limits; junction temperature = ambient +6°C at high temperature limit for over temperature specifications. Test levels: (A) 100% tested at +25°C. Over temperature limits by characterization and simulation. (B) Limits set by characterization and simulation. (C) Typical value only for information. Current is considered positive out of pin. Submit Documentation Feedback 5 OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 ELECTRICAL CHARACTERISTICS: VS = +5V (continued) Boldface limits are tested at +25°C. At TA = +25°C, G = +2V/V, RF = 750Ω, and RL = 150Ω to VS/2, unless otherwise noted (see Figure 72). OPA2830ID, IDGK TYP PARAMETER Closed-Loop Output Impedance CONDITIONS G = +2, f ≤ 100kHz +25°C 0.06 MIN/MAX OVER TEMPERATURE +25°C (1) 0°C to +70°C (2) –40°C to +85°C (2) UNITS Ω MIN/ MAX typ TEST LEVEL (3) C 6 Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 ELECTRICAL CHARACTERISTICS: VS = +5V (continued) Boldface limits are tested at +25°C. At TA = +25°C, G = +2V/V, RF = 750Ω, and RL = 150Ω to VS/2, unless otherwise noted (see Figure 72). OPA2830ID, IDGK TYP PARAMETER POWER SUPPLY Minimum Operating Voltage Maximum Operating Voltage Maximum Quiescent Current Minimum Quiescent Current Power-Supply Rejection Ratio (PSRR) THERMAL CHARACTERISTICS Specification: ID, IDGK Thermal Resistance, θJA D DGK SO-8 MSOP-8 125 150 °C/W °C/W typ typ C C –40 to +85 °C typ C VS = +5V, Both Channels VS = +5V, Both Channels Input-Referred 7.8 7.8 66 +2.8 +11 8.3 7.4 61 +11 9.7 6.8 60 +11 11.1 6.2 59 V V mA mA dB min max max min min B A A A A CONDITIONS +25°C MIN/MAX OVER TEMPERATURE +25°C (1) 0°C to +70°C (2) –40°C to +85°C (2) UNITS MIN/ MAX TEST LEVEL (3) Submit Documentation Feedback 7 OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 ELECTRICAL CHARACTERISTICS: VS = +3V Boldface limits are tested at +25°C. At TA = +25°C, G = +2V/V, and RL = 150Ω to VS/3, unless otherwise noted (see Figure 71). OPA2830ID, IDGK TYP PARAMETER AC PERFORMANCE (see Figure 71) Small-Signal Bandwidth G = +2, VO ≤ 0.2VPP G = +5, VO ≤ 0.2VPP G = +10, VO ≤ 0.2VPP Gain-Bandwidth Product Slew Rate Rise Time Fall Time Settling Time to 0.1% Harmonic Distortion 2nd-Harmonic G ≥ +10 1V Step 0.5V Step 0.5V Step 1V Step VO = 1VPP, f = 5MHz RL = 150Ω RL ≥ 500Ω 3rd-Harmonic RL = 150Ω RL ≥ 500Ω Input Voltage Noise Input Current Noise DC PERFORMANCE (4) Open-Loop Voltage Gain Input Offset Voltage Average Offset Voltage Drift Input Bias Current Input Bias Current Drift Input Offset Current Input Offset Current Drift INPUT Least Positive Input Voltage Most Positive Input Voltage Common-Mode Rejection Ratio (CMRR) Input Impedance Differential Mode Common-Mode OUTPUT Least Positive Output Voltage G = +5, RL = 1kΩ to 1.5V G = +5, RL = 150Ω to 1.5V Most Positive Output Voltage G = +5, RL = 1kΩ to 1.5V G = +5, RL = 150Ω to 1.5V Current Output, Sinking and Sourcing Short-Circuit Output Current Closed-Loop Output Impedance Output Shorted to Either Supply See Figure 71, f < 100kHz 0.08 0.17 2.91 2.82 ±30 45 0.06 0.11 0.39 2.88 2.74 ±20 0.125 0.40 2.85 2.70 ±18 V V V V mA mA Ω max max min min min typ typ A A A A A C C 10 | | 2.1 400 | | 1.2 kΩ | | pF kΩ | | pF typ typ C C Input-Referred –0.45 1.2 80 –0.4 1.1 74 –0.27 1.0 72 V V dB max min min A A A VCM = 1.0V ±0.2 — ±1.1 VCM = 1.0V 72 ±1.5 — +5 +10 66 ±7.5 65 ±8.7 ±27 +12 ±44 ±1.3 ±5 dB mV µV/°C µA nA/°C µA nA/°C min max max max max max max A A B A B A B f > 1MHz f > 1MHz –60 –64 –68 –72 9.2 3.5 –56 –59 –59 –65 10.3 4.6 –54 –57 –58 –64 10.8 5.1 dBc dBc dBc dBc nV/√Hz pA/√Hz min min min min max max B B B B B B 90 20 9 90 220 3.4 3.4 46 70 15 7.5 75 135 5.6 5.6 73 66 14 6.5 65 105 5.7 5.7 88 MHz MHz MHz MHz V/µs ns ns ns min min min min min max max max B B B B B B B B CONDITIONS +25°C MIN/MAX OVER TEMPERATURE +25°C (1) 0°C to +70°C (2) UNITS MIN/ MAX TEST LEVEL (3) (1) (2) (3) (4) Junction temperature = ambient for +25°C specifications. Junction temperature = ambient at low temperature limits; junction temperature = ambient +20°C at high temperature limit for over temperature specifications. Test levels: (A) 100% tested at +25°C. Over temperature limits by characterization and simulation. (B) Limits set by characterization and simulation. (C) Typical value only for information. Current is considered positive out of node. 8 Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 ELECTRICAL CHARACTERISTICS: VS = +3V (continued) Boldface limits are tested at +25°C. At TA = +25°C, G = +2V/V, and RL = 150Ω to VS/3, unless otherwise noted (see Figure 71). OPA2830ID, IDGK TYP PARAMETER POWER SUPPLY Minimum Operating Voltage Maximum Operating Voltage Maximum Quiescent Current Minimum Quiescent Current Power-Supply Rejection Ratio (PSRR) THERMAL CHARACTERISTICS Specification: ID, IDGK Thermal Resistance, θJA D DGK SO-8 MSOP-8 125 150 °C/W °C/W typ typ C C –40 to +85 °C typ C VS = +3V, Both Channels VS = +3V, Both Channels Input-Referred 7.4 7.4 64 +2.8 +11 8.1 6.6 60 +11 8.7 6.2 58 V V mA mA dB min max max min min B A A A A CONDITIONS +25°C MIN/MAX OVER TEMPERATURE +25°C (1) 0°C to +70°C (2) UNITS MIN/ MAX TEST LEVEL (3) Submit Documentation Feedback 9 OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 TYPICAL CHARACTERISTICS: VS = ±5V At TA = +25°C, G = +2V/V, RF = 750Ω, and RL = 150Ω to GND, unless otherwise noted (see Figure 72). NONINVERTING SMALL-SIGNAL FREQUENCY RESPONSE 6 3 Normalized Gain (dB) 0 −3 −6 −9 − 12 − 15 − 18 1 VO = 0.2VPP RL = 150Ω See Figure 72 10 Frequency (MHz) 100 600 G = +10 G = +5 G = +2 G = +1 RF = 0Ω Normalized Gain (dB) INVERTING SMALL-SIGNAL FREQUENCY RESPONSE 3 0 −3 −6 −9 − 12 − 15 − 18 1 VO = 0.2VPP RL = 150Ω 10 Frequency (MHz) 100 400 G = −5 G = − 10 G = −2 G = −1 Figure 1. NONINVERTING LARGE-SIGNAL FREQUENCY RESPONSE 9 6 3 Gain (dB) Gain (dB) 0 −3 −6 −9 − 12 10 Frequency (MHz) G = +2V/V RL = 150Ω See Figure 72 VO = 4VPP VO = 2VPP VO = 0.5VPP 100 400 VO = 1VPP Figure 2. INVERTING LARGE-SIGNAL FREQUENCY RESPONSE 3 0 −3 −6 VO = 0.5VPP −9 − 12 − 15 − 18 10 G = − 1V/V RL = 150Ω 100 Frequency (MHz) 400 VO = 4VPP VO = 2VPP VO = 1VPP Figure 3. NONINVERTING PULSE RESPONSE 0.4 Small−Signal Output Voltage (V) 0.3 0.2 0.1 0 − 0.1 − 0.2 − 0.3 − 0.4 Time (10ns/div) Small−Signal ± 100mV Left Scale G = +2V/V See Figure 72 Large−Signal ± 1V Right Scale 2.0 Large−Signal Output Voltage (V) Small−Signal Output Voltage (V) 1.5 1.0 0.5 0 − 0.5 − 1.0 − 1.5 − 2.0 0.4 0.3 0.2 0.1 0 − 0.1 − 0.2 − 0.3 − 0.4 G = − 1V/V Figure 4. INVERTING PULSE RESPONSE 2.0 1.5 1.0 0.5 Small−Signal ± 100mV Left Scale 0 − 0.5 Large−Signal ± 1V Right Scale Time (10ns/div) − 1.0 − 1.5 − 2.0 Large−Signal Output Voltage (V) Figure 5. Figure 6. 10 Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 TYPICAL CHARACTERISTICS: VS = ±5V (continued) At TA = +25°C, G = +2V/V, RF = 750Ω, and RL = 150Ω to GND, unless otherwise noted (see Figure 72). HARMONIC DISTORTION vs LOAD RESISTANCE − 50 − 55 Harmonic Distortion (dBc) − 60 − 65 − 70 − 75 − 80 G = +2V/V VO = 2VPP f = 5MHz See Figure 72 2nd−Harmonic 5MHz HARMONIC DISTORTION vs SUPPLY VOLTAGE − 40 − 45 Harmonic Distortion (dBc) − 50 − 55 − 60 − 65 − 70 − 75 − 80 − 85 − 90 3rd−Harmonic 2nd−Harmonic Input Limited for VCM = 0V G = +2V/V VO = 2VPP R L = 500Ω See Figure 72 3rd−Harmonic − 85 100 1k Resistance (Ω ) 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 Supply Voltage (± VS) Figure 7. HARMONIC DISTORTION vs OUTPUT VOLTAGE − 55 − 60 Harmonic Distortion (dBc) − 65 − 70 − 75 − 80 − 85 − 90 − 95 0.1 1 Output Voltage Swing (VPP) 10 3rd−Harmonic G = +2V/V RL = 500Ω f = 5MHz See Figure 72 2nd−Harmonic Harmonic Distortion (dBc) − 50 − 55 − 60 − 65 − 70 − 75 − 80 − 85 − 90 − 95 − 100 − 105 0.1 G = +2V/V VO = 2VPP See Figure 72 Figure 8. HARMONIC DISTORTION vs FREQUENCY 3rd−Harmonic RL = 150Ω 2nd−Harmonic RL = 500Ω 2nd−Harmonic RL = 150Ω 3rd−Harmonic RL = 500Ω 1 Frequency (MHz) 10 Figure 9. TWO-TONE, 3RD-ORDER INTERMODULATION SPURIOUS − 40 3rd−Order Spurious Level (dBc) − 45 − 50 − 55 − 60 − 65 − 70 − 75 − 80 − 85 − 90 − 26 − 20 − 14 −8 −2 6 77 − 50 − 25 5MHz PI 50Ω 1 /2 O P A 28 30 Figure 10. SUPPLY AND OUTPUT CURRENT vs TEMPERATURE 83 13 12 11 Output Current (sourcing) 80 79 78 Quiescent Current (total, both amplifiers) 7 0 25 50 75 100 125 Ambient Temperature (_ C) Output Current (sinking) 10 9 8 Supply Current (mA) PO 500 Ω 20MHz Output Current (mA) 82 81 750Ω 750 Ω 10MHz Single−Tone Load Power (2dBm/div) Figure 11. Figure 12. Submit Documentation Feedback 11 OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 TYPICAL CHARACTERISTICS: VS = ±5V (continued) At TA = +25°C, G = +2V/V, RF = 750Ω, and RL = 150Ω to GND, unless otherwise noted (see Figure 72). FREQUENCY RESPONSE vs CAPACITIVE LOAD Normalized Gain to Capacitive Load (dB) 8 7 6 5 4 3 2 1 0 −1 −2 −3 1 10 Frequency (MHz) 100 200 VI 50Ω 1/2 O PA2830 RECOMMENDED RS vs CAPACITIVE LOAD 120 110 100 90 80 RS (Ω ) 70 60 50 40 30 20 10 1 10 100 1k Capacitive Load (pF) 0dB Peaking Targeted CL = 10pF CL = 100pF CL = 1000pF RS VO CL (1) 1k Ω 750Ω 750 Ω NOTE: (1) 1kΩ is optional. Figure 13. OUTPUT SWING vs LOAD RESISTANCE 6 5 4 Output Voltage (V) 3 VO (V) 2 1 0 −1 −2 −3 −4 −5 −6 10 100 Resistance (Ω ) 1k G = +5V/V VS = ± 5V 6 5 4 3 2 1 0 −1 −2 −3 −4 −5 Outpu t Current Limit One Channel Only Figure 14. OUTPUT VOLTAGE AND CURRENT LIMITATIONS 1W In ternal Power Lim it Output Current Lim it RL = 500Ω RL = 50Ω RL = 100Ω 1W Internal P ower Limit −6 − 160 − 120 − 80 − 40 0 IO (mA) 40 80 120 160 Figure 15. Figure 16. 12 Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 TYPICAL CHARACTERISTICS: VS = ±5V, Differential Configuration At TA = +25°C, RF = 604Ω (as shown in Figure 17), and RL = 500Ω, unless otherwise noted. DIFFERENTIAL SMALL-SIGNAL FREQUENCY RESPONSE +5V 3 GD = 1 0 20Ω RG Normalized Gain (dB) 1/2 OPA2830 GD = 2 −3 −6 GD = 5 −9 GD = 10 − 12 VO = 200mVPP RL = 500Ω 1 10 Frequency (MHz) 100 200 604Ω RL 500Ω VI RG 604Ω VO 1/2 OPA2830 − 15 Ω GD = 604 RG 20Ω − 5V Figure 17. DIFFERENTIAL LARGE-SIGNAL FREQUENCY RESPONSE 9 6 VO = 5VPP 3 Gain (dB) 0 −3 −6 −9 1 VO = 2VPP VO = 1VPP GD = 2 RL = 500Ω 10 Frequency (MHz) VO = 200mVPP 100 200 Figure 18. DIFFERENTIAL DISTORTION vs LOAD RESISTANCE − 45 − 50 Harmonic Distortion (dBc) − 55 − 60 − 65 − 70 − 75 − 80 − 85 − 90 − 95 − 100 100 150 200 250 300 2nd−Harmonic GD = 2 VO = 4VPP f = 5MHz 3rd−Harmonic 350 400 450 500 Resistance (Ω ) Figure 19. DIFFERENTIAL DISTORTION vs FREQUENCY − 40 − 50 Harmonic Distortion (dBc) − 60 − 70 − 80 − 90 − 100 2nd−Harmonic − 110 0.1 1 10 Frequency (MHz) 100 GD = 2 VO = 4VPP RL = 500Ω 3rd−Harmonic Figure 20. DIFFERENTIAL DISTORTION vs OUTPUT VOLTAGE − 55 − 60 Harmonic Distrtion (dBc) − 65 − 70 − 75 − 80 − 85 − 90 − 95 − 100 − 105 1 Output Voltage Swing (VPP) 10 2nd−Harmonic GD = 2 RL = 500Ω f = 5MHz 3rd−Harmonic Figure 21. Figure 22. Submit Documentation Feedback 13 OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 TYPICAL CHARACTERISTICS: VS = +5V At TA = +25°C, G = +2V/V, RF = 750Ω, RL = 150Ω to VS/2, and input VCM = 2.5V, unless otherwise noted (see Figure 70). NONINVERTING SMALL-SIGNAL FREQUENCY RESPONSE 6 3 Normalized Gain (dB) 0 −3 −6 −9 − 12 − 15 − 18 1 G = +10 VO = 0.2VPP RL = 150Ω See Figure 70 10 Frequency (MHz) 100 500 G = +2 G = +5 G = +1 RF = 0Ω Normalized Gain (dB) INVERTING SMALL-SIGNAL FREQUENCY RESPONSE 3 0 −3 −6 −9 − 12 − 15 − 18 1 VO = 0.2VPP RL = 150Ω See Figure 84 10 Frequency (MHz) 100 300 G = − 10 G = −5 G = −1 G = −2 Figure 23. NONINVERTING LARGE-SIGNAL FREQUENCY RESPONSE 9 6 3 Gain (dB) Gain (dB) 0 VO = 0.5VPP −3 −6 −9 − 12 10 G = +2V/V RL = 150Ω See Figure 70 VO = 2VPP VO = 1VPP Figure 24. INVERTING LARGE-SIGNAL FREQUENCY RESPONSE 3 0 −3 −6 −9 − 12 − 15 − 18 G = − 1V/V RL = 150Ω See Figure 84 10 Frequency (MHz) 100 300 VO = 0.5VPP VO = 1VPP VO = 2VPP 100 Frequency (MHz) 400 Figure 25. NONINVERTING PULSE RESPONSE 2.9 Small−Signal Output Voltage (V) 2.8 2.7 2.6 2.5 2.4 2.3 2.2 2.1 Time (10ns/div) G = +2V/V See Figure 70 Small−Signal 2.4V to 2.6V Left Scale Large−Signal 1.5V to 3.5V Right Scale 4.5 Large−Signal Output Voltage (V) Small−Signal Output Voltage (V) 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 2.9 2.8 2.7 2.6 2.5 2.4 2.3 2.2 2.1 G = − 1V/V Figure 26. INVERTING PULSE RESPONSE 4.5 4.0 3.5 3.0 Small−Signal 2.4V to 2.6V Left Scale 2.5 2.0 1.5 Large−Signal 1.5V to 3.5V Right Scale Time (10ns/div) 1.0 0.5 Large−Signal Output Voltage (V) Figure 27. Figure 28. 14 Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 TYPICAL CHARACTERISTICS: VS = +5V (continued) At TA = +25°C, G = +2V/V, RF = 750Ω, RL = 150Ω to VS/2, and input VCM = 2.5V, unless otherwise noted (see Figure 70). HARMONIC DISTORTION vs LOAD RESISTANCE − 50 − 55 Harmonic Distortion (dBc) − 60 − 65 − 70 − 75 − 80 − 85 G = +2V/V VO = 2VPP f = 5MHz See Figure 70 1k Load Resistance (Ω ) 3rd−Harmonic 2nd−Harmonic − 45 − 50 Harmonic Distortion (dBc) − 55 − 60 − 65 − 70 − 75 − 80 − 85 − 90 − 95 − 100 0.1 3rd−Harmonic RL = 150Ω 1 Frequency (MHz) 10 2nd−Harmonic RL = 150Ω 2nd−Harmonic RL = 500Ω 3rd−Harmonic RL = 500Ω HARMONIC DISTORTION vs FREQUENCY G = +2V/V VO = 2VPP See Figure 70 − 90 100 Figure 29. HARMONIC DISTORTION vs OUTPUT VOLTAGE − 45 − 50 Harmonic Distortion (dBc) − 55 − 60 − 65 − 70 − 75 − 80 − 85 − 90 − 95 − 100 0.1 1 Output Voltage Swing (VPP ) 10 3rd−Harmonic G = +2V/V RL = 500Ω f = 5MHz See Figure 70 Input Limited Harmonic Distortion (dBc) 2nd−Harmonic Figure 30. HARMONIC DISTORTION vs NONINVERTING GAIN − 55 − 60 − 65 − 70 − 75 − 80 − 85 − 90 1 Gain (V/V) 10 3rd−Harmonic RL = 500Ω VO = 2VPP f = 5MHz See Figure 70 2nd−Harmonic Figure 31. HARMONIC DISTORTION vs INVERTING GAIN − 55 3rd−Order Spurious Level (dBc) − 60 2nd−Harmonic − 65 − 70 − 75 − 80 − 85 1 Gain ( V/V ) 10 3rd−Harmonic RL = 500Ω VO = 2VPP f = 5MHz Figure 32. TWO-TONE, 3RD-ORDER INTERMODULATION SPURIOUS − 45 − 50 − 55 − 60 − 65 − 70 − 75 − 80 − 85 − 90 − 95 − 26 − 24 − 22 − 20 − 18 − 16 − 14 − 12 − 10 − 8 Single−Tone Load Power (dBm) −6 −4 −2 5MHz PI 50Ω 1 /2 O P A28 30 PO 500 Ω 20MHz Harmonic Distortion (dBc) 750Ω 750 Ω 10MHz Figure 33. Figure 34. Submit Documentation Feedback 15 OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 TYPICAL CHARACTERISTICS: VS = +5V (continued) At TA = +25°C, G = +2V/V, RF = 750Ω, RL = 150Ω to VS/2, and input VCM = 2.5V, unless otherwise noted (see Figure 70). INPUT VOLTAGE AND CURRENT NOISE DENSITY 100 CLOSED-LOOP OUTPUT IMPEDANCE vs FREQUENCY 100 Voltage Noise (nV/ √ Hz) Current Noise (pA/√ Hz) Output Impedance (Ω ) 10 Voltage Noise (9.2nV/√ Hz) 10 1 Current Noise (3.5pA/√ Hz) 1 10 100 1k 10k 100k 1M 10M Frequency (Hz) 0.1 0.01 1k 10k 100k 1M 10M 100M Frequency (Hz) Figure 35. RECOMMENDED RS vs CAPACITIVE LOAD Normalized Gain to Capacitive Load (dB) 130 120 110 100 90 RS (Ω ) 80 70 60 50 40 30 20 10 1 10 100 1k Capacitive Load (pF) < 0.5dB Peaking Targeted 8 7 6 5 4 3 2 1 0 −1 −2 −3 1 VI 50Ω 1/2 OPA2830 Figure 36. FREQUENCY RESPONSE vs CAPACITIVE LOAD CL = 10pF CL = 100pF CL = 1000pF RS VO CL 1k Ω(1) 750 Ω 750 Ω NOTE: (1) 1k Ω is optional. 10 Frequency (MHz) 100 300 Figure 37. OPEN-LOOP GAIN AND PHASE 80 70 Open−Loop Gain (dB) 60 50 40 30 20 10 0 − 10 − 20 100 1k 10k 100k 1M 10M 100M 1G ∠ (AOL) 20 log (AOL) 180 160 Open−Loop Phase (dB) 140 120 100 80 60 40 20 0 − 20 Frequency (Hz) Voltage Range (V) 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 − 0.5 − 1.0 − 50 0 Figure 38. VOLTAGE RANGES vs TEMPERATURE Most Positive Output Voltage Most Positive Input Voltage RL = 150Ω Least Positive Output Voltage Least Positive Input Voltage 50 110 Ambient Temperature (10_ C/div) Figure 39. Figure 40. 16 Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 TYPICAL CHARACTERISTICS: VS = +5V (continued) At TA = +25°C, G = +2V/V, RF = 750Ω, RL = 150Ω to VS/2, and input VCM = 2.5V, unless otherwise noted (see Figure 70). TYPICAL DC DRIFT OVER TEMPERATURE 4 Input Bias Current (IB) 3 Input Offset Voltage (mV) 2 1 0 −1 −2 −3 −4 − 50 − 25 0 25 50 75 100 125 Input Offset Voltage (VOS) 10 × Input Offset Current (IOS) 6 4 2 0 −2 −4 −6 −8 Ambient Temperature (_ C) 8 Input Bias and Offset Current (µ A) 100 95 Output Current (mA) 90 85 Output Current, Sinking 80 75 Output Current, Sourcing 70 65 60 − 50 − 25 0 25 50 75 100 125 7.5 7.0 6.5 Ambient Temperature (_ C) 8.5 8.0 Quiescent Current SUPPLY AND OUTPUT CURRENT vs TEMPERATURE 10.5 10.0 Supply Current (mA) 9.5 9.0 Figure 41. CMRR AND PSRR vs FREQUENCY 90 Common−Mode Rejection Ratio (dB) Power−Supply Rejection Ratio (dB) 80 70 60 50 40 30 20 10 0 1k 10k 100k 1M 10M 100M Frequency (Hz) PSRR Output Voltage (V) CMRR 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 − 0.5 10 Figure 42. OUTPUT SWING vs LOAD RESISTANCE G = +5V/V 100 Load Resistance (Ω ) 1k Figure 43. Figure 44. Submit Documentation Feedback 17 OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 TYPICAL CHARACTERISTICS: VS = +5V, Differential Configuration At TA = +25°C, RF = 604Ω, and RL = 500Ω differential (as shown in Figure 45), unless otherwise noted. DIFFERENTIAL SMALL-SIGNAL FREQUENCY RESPONSE +5V 1.2kΩ 1.2kΩ RG 3 GD = 1 0 Normalized Gain (dB) 2.5V 0.1µF 1/2 OPA2830 GD = 2 −3 −6 GD = 5 −9 GD = 10 − 12 − 15 VO = 200mVPP RL = 500Ω 1 10 Frequency (MHz) 100 200 604 Ω RL VO VI RG 604 Ω Ω GD = 604 RG 1/2 OPA2830 2.5V Figure 45. DIFFERENTIAL LARGE-SIGNAL FREQUENCY RESPONSE 9 6 VO = 3VPP 3 Gain (dB) 0 −3 VO = 1VPP −6 −9 GD = 2 RL = 500Ω 1 10 Frequency (MHz) VO = 0.2VPP 100 200 VO = 2VPP Figure 46. DIFFERENTIAL DISTORTION vs LOAD RESISTANCE − 40 − 45 Harmonic Distortion (dBc) − 50 − 55 − 60 − 65 − 70 − 75 − 80 − 85 − 90 100 150 200 250 300 2nd−Harmonic 350 400 450 500 GD = 2 VO = 4VPP f = 5MHz 3rd−Harmonic Resistance (Ω ) Figure 47. DIFFERENTIAL DISTORTION vs FREQUENCY − 30 − 40 Harmonic Distrtion (dBc) − 50 − 60 − 70 − 80 − 90 − 100 − 110 1 10 Frequency (MHz) 100 2nd−Harmonic GD = 2 VO = 4VPP RL = 500Ω Figure 48. DIFFERENTIAL DISTORTION vs OUTPUT VOLTAGE − 55 − 60 Harmonic Distrtion (dBc) 3rd−Harmonic − 65 − 70 − 75 − 80 − 85 − 90 − 95 − 100 1 Output Voltage Swing (VPP) 10 2nd−Harmonic GD = 2 RL = 500Ω f = 5MHz 3rd−Harmonic Figure 49. Figure 50. 18 Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 TYPICAL CHARACTERISTICS: VS = +3V At TA = +25°C, G = +2V/V, and RL = 150Ω to VS/3, unless otherwise noted (see Figure 71). NONINVERTING SMALL-SIGNAL FREQUENCY RESPONSE 6 3 Normalized Gain (dB) 0 −3 −6 −9 − 12 − 15 − 18 1 RL = 150Ω VO = 0.2VPP See Figure 71 10 Frequency (MHz) G = +10 G = +5 G = +2 G = +1 RF = 0 Normalized Gain (dB) INVERTING SMALL-SIGNAL FREQUENCY RESPONSE 3 0 −3 −6 −9 − 12 − 15 − 18 RL = 150Ω VO = 0.2VPP 1 10 Frequency (MHz) G = − 10 G = −5 G = −2 G = −1 100 400 100 300 Figure 51. NONINVERTING LARGE-SIGNAL FREQUENCY RESPONSE 9 6 3 Gain (dB) Gain (dB) VO = 0.5VPP 0 −3 −6 −9 − 12 10 Frequency (MHz) G = +2V/V RL = 150Ω See Figure 71 100 300 VO = 1.5VPP VO = 1VPP Figure 52. INVERTING LARGE-SIGNAL FREQUENCY RESPONSE 3 0 −3 −6 −9 − 12 − 15 − 18 10 Frequency (MHz) 100 300 G = − 1V/V RL = 150Ω VO = 1.5VPP VO = 1VPP VO = 0.5VPP Figure 53. NONINVERTING PULSE RESPONSE 1.20 Small−Signal Output Voltage (V) 1.15 1.10 1.05 1.00 0.95 0.90 0.85 0.80 Time (10ns/div) G = +2V/V See Figure 71 Small−Signal 0.95V to 1.05V Left Scale Large−Signal 0.5V to 1.5V Right Scale 2.00 Large−Signal Output Voltage (V) Small−Signal Output Voltage (V) 1.75 1.50 1.25 1.00 0.75 0.50 0.25 0 1.20 1.15 1.10 1.05 1.00 0.95 0.90 0.85 0.80 G = − 1V/V RL = 150Ω Figure 54. INVERTING PULSE RESPONSE 2.00 1.75 1.50 1.25 Small−Signal 0.95V to 1.05V Left Scale 1.00 0.75 0.50 Large−Signal 0.5V to 1.5V Right Scale Time (10ns/div) 0.25 0 Large−Signal Output Voltage (V) Figure 55. Figure 56. Submit Documentation Feedback 19 OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 TYPICAL CHARACTERISTICS: VS = +3V (continued) At TA = +25°C, G = +2V/V, and RL = 150Ω to VS/3, unless otherwise noted (see Figure 71). HARMONIC DISTORTION vs LOAD RESISTANCE − 50 − 55 Harmonic Distortion (dBc) − 60 − 65 − 70 − 75 3rd−Harmonic − 80 − 85 − 90 100 Resistance (Ω ) 1k 2nd−Harmonic G = +2V/V VO = 1VPP f = 5MHz See Figure 71 − 30 − 40 − 50 − 60 2nd−Harmonic − 70 3rd−Harmonic − 80 − 90 0.1 1 Output Voltage Swing (VPP ) 10 G = +2V/V RL = 500Ω f = 5MHz See Figure 71 HARMONIC DISTORTION vs OUTPUT VOLTAGE Harmonic Distortion (dBc) Input Limited Figure 57. HARMONIC DISTORTION vs FREQUENCY − 55 3rd−Order Spurious Level (dBc) − 60 Harmonic Distortion (dBc) − 65 − 70 − 75 − 80 − 85 − 90 − 95 − 100 0.1 1 Frequency (MHz) 10 2nd−Harmonic RL = 150Ω 3rd−Harmonic RL = 150Ω 3rd−Harmonic RL = 500Ω G = +2V/V VO = 1VPP See Figure 71 2nd−Harmonic RL = 500Ω Figure 58. TWO-TONE, 3RD-ORDER INTERMODULATION SPURIOUS − 40 − 45 − 50 − 55 − 60 − 65 − 70 − 75 − 80 − 85 − 90 5MHz 10MHz PI 50Ω 1/2 O P A 2830 PO 500Ω 750Ω 750Ω 20MHz − 95 − 28 − 26 − 24 − 22 − 20 − 18 − 16 − 14 − 12 − 10 Single−Tone Load Power (dBm) −8 Figure 59. RECOMMENDED RS vs CAPACITIVE LOAD Normalized Gain to Capacitive Load (dB) 190 < 0.5dB Peaking Targeted 170 150 130 RS (Ω ) 110 90 70 50 30 10 1 10 100 1k Capacitive Load (pF) 8 7 6 5 4 3 2 1 0 −1 −2 −3 1 VI 50 Ω O PA2830 Figure 60. FREQUENCY RESPONSE vs CAPACITIVE LOAD CL = 10pF CL = 100pF CL = 1000pF RS VO CL 750Ω 750 Ω NOTE: (1) 1kΩ is optional. 1kΩ(1) 10 Frequency (MHz) 100 200 Figure 61. Figure 62. 20 Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 TYPICAL CHARACTERISTICS: VS = +3V (continued) At TA = +25°C, G = +2V/V, and RL = 150Ω to VS/3, unless otherwise noted (see Figure 71). OUTPUT SWING vs LOAD RESISTANCE 3.5 3.0 Output Voltage (V) 2.5 2.0 1.5 1.0 0.5 0 − 0.5 10 100 Load Resistance (Ω ) 1k G = +5V/V Figure 63. Submit Documentation Feedback 21 OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 TYPICAL CHARACTERISTICS: VS = +3V, Differential Configuration At TA = +25°C, RF = 604Ω, and RL = 500Ω differential (as shown in Figure 64), unless otherwise noted. DIFFERENTIAL SMALL-SIGNAL FREQUENCY RESPONSE +3V 2kΩ 1kΩ RG 3 0 Normalized Gain (dB) 1V 0.1µF 1/2 OPA2830 604Ω GD = 1 −3 −6 −9 − 12 − 15 GD = 5 GD = 10 VO = 200mVPP RL = 500Ω 1 10 Frequency (MHz) 100 200 GD = 2 RL VI RG 604Ω VO 1/2 OPA2830 1V GD = 604Ω RG Figure 64. DIFFERENTIAL LARGE-SIGNAL FREQUENCY RESPONSE 9 6 3 Gain (dB) 0 VO = 1VPP −3 VO = 200mVPP −6 −9 GD = 2 1 10 Frequency (MHz) 100 200 Figure 65. DIFFERENTIAL DISTORTION vs LOAD RESISTANCE − 40 − 45 Harmonic Distortion (dBc) − 50 − 55 − 60 − 65 − 70 − 75 − 80 − 85 − 90 100 2nd−Harmonic GD = 2 VO = 4VPP f = 5MHz 3rd−Harmonic VO = 2VPP 150 200 250 300 350 400 450 500 Resistance (Ω ) Figure 66. DIFFERENTIAL DISTORTION vs FREQUENCY − 35 − 45 Harmonic Distortion (dBc) − 55 − 65 − 75 − 85 − 95 − 105 − 115 0.1 1 10 Frequency (MHz) 100 2nd−Harmonic GD = 2 VO = 2VPP RL = 500Ω Figure 67. DIFFERENTIAL DISTORTION vs OUTPUT VOLTAGE − 75 − 80 − 85 − 90 − 95 − 100 0.50 2nd−Harmonic GD = 2 RL = 500Ω f = 5MHz Harmonic Distortion (dBc) 3rd−Harmonic 3rd−Harmonic 0.75 1.00 1.25 1.50 1.75 2.00 Output Voltage Swing (VPP) Figure 68. Figure 69. 22 Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 APPLICATIONS INFORMATION WIDEBAND VOLTAGE-FEEDBACK OPERATION The OPA2830 is a unity-gain stable, very high-speed voltage-feedback op amp designed for single-supply operation (+3V to +10V). The input stage supports input voltages below ground and to within 1.7V of the positive supply. The complementary common-emitter output stage provides an output swing to within 25mV of ground and the positive supply. The OPA2830 is compensated to provide stable operation with a wide range of resistive loads. Figure 70 shows the AC-coupled, gain of +2 configuration used for the +5V Specifications and Typical Characteristic Curves. For test purposes, the input impedance is set to 50Ω with a resistor to ground. Voltage swings reported in the Electrical Characteristics are taken directly at the input and output pins. For the circuit of Figure 70, the total effective load on the output at high frequencies is 150Ω || 1500Ω. The 1.5kΩ resistors at the noninverting input provide the common-mode bias voltage. Their parallel combination equals the DC resistance at the inverting input (RF), reducing the DC output offset due to input bias current. VS = +5V 6.8µF + 1.5kΩ 0.1µ F VIN 53.6Ω 0.1µF high frequencies is 150Ω || 1500Ω. The 1.13kΩ and 2.26kΩ resistors at the noninverting input provide the common-mode bias voltage. Their parallel combination equals the DC resistance at the inverting input (RF), reducing the DC output offset due to input bias current. VS = +3V 6.8µF + 2.26kΩ 0.1µ F VIN 53.6Ω 1.13kΩ 1/2 OPA2830 RL 150Ω RG 750Ω +VS/3 RF 750Ω VOUT 0.1µF +1V +VS 3 Figure 71. AC-Coupled, G = +2, +3V Single-Supply Specification and Test Circuit Figure 72 shows the DC-coupled, gain of +2, dual power-supply circuit configuration used as the basis of the ±5V Electrical Characteristics and Typical Characteristics. For test purposes, the input impedance is set to 50Ω with a resistor to ground and the output impedance is set to 150Ω with a series output resistor. Voltage swings reported in the specifications are taken directly at the input and output pins. For the circuit of Figure 72, the total effective load will be 150Ω || 1.5kΩ. Two optional components are included in Figure 72. An additional resistor (348Ω) is included in series with the noninverting input. Combined with the 25Ω DC source resistance looking back towards the signal generator, this gives an input bias current cancelling resistance that matches the 375Ω source resistance seen at the inverting input (see the DC Accuracy and Offset Control section). In addition to the usual power-supply decoupling capacitors to ground, a 0.01µF capacitor is included between the two power-supply pins. In practical PC board layouts, this optional capacitor will typically improve the 2nd-harmonic distortion performance by 3dB to 6dB. 2.5V 1.5kΩ 1/2 OPA2830 RL 150Ω RG 750Ω RF 750Ω VOUT +VS 2 +VS/2 Figure 70. AC-Coupled, G = +2, +5V Single-Supply Specification and Test Circuit Figure 71 shows the AC-coupled, gain of +2 configuration used for the +3V Specifications and Typical Characteristic Curves. Voltage swings reported in the Electrical Characteristics are taken directly at the input and output pins. For the circuit of Figure 71, the total effective load on the output at Submit Documentation Feedback 23 OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 +5V 0.1µF 6.8µ F + 50Ω Source VIN 50Ω 348Ω 1/2 OPA2830 VO 150Ω voltage range. Given the desired signal gain (G), and the amount VOUT needs to be shifted up (∆VOUT) when VIN is at the center of its range, the following equations give the resistor values that produce the desired performance. Assume that R4 is between 200Ω and 1.5kΩ. • NG = G + VOUT/VS • R1 = R4/G • R2 = R4/(NG – G) • R3 = R4/(NG – 1) where: • NG = 1 + R4/R3 • VOUT = (G)VIN + (NG – G)VS 0.01µF RF 750Ω RG 750Ω + − 5V 6.8µ F 0.1µ F Make sure that VIN and VOUT stay within the specified input and output voltage ranges. +VS R2 R1 VIN 1/2 OPA2830 Figure 72. DC-Coupled, G = +2, Bipolar Supply Specification and Test Circuit SINGLE-SUPPLY ADC INTERFACE The ADC interface of Figure 73 shows a DC-coupled, single-supply ADC driver circuit. Many systems are now requiring +3V to +5V supply capability of both the ADC and its driver. The OPA2830 provides excellent performance in this demanding application. Its large input and output voltage ranges and low distortion support converters such as the ADS5203 shown in the figure on page 1. The input level-shifting circuitry was designed so that VIN can be between 0V and 0.5V, while delivering an output voltage of 1V to 2V for the ADS5203. +3V 2.26kΩ 374Ω VIN 1/2 OPA2830 VOUT R3 R4 Figure 74. DC Level-Shifting The circuit of Figure 73 is a good example of this type of application. It was designed to take VIN between 0V and 0.5V and produce VOUT between 1V and 2V when using a +3V supply. This means G = 2.00, and ∆VOUT = 1.50V – G × 0.25V = 1.00V. Plugging these values into the above equations (with R4 = 750Ω) gives: NG = 2.33, R1 = 375Ω, R2 = 2.25kΩ, and R3 = 563Ω. The resistors were changed to the nearest standard values for the circuit of Figure 73. +3V 100Ω 22pF 562Ω 750Ω 1/2 ADS5203 10−Bit 30MSPS AC-COUPLED OUTPUT VIDEO LINE DRIVER Figure 73. DC-Coupled, +3V ADC Driver Low-power and low-cost video line drivers often buffer digital-to-analog converter (DAC) outputs with a gain of 2 into a doubly-terminated line. Those interfaces typically require a DC blocking capacitor. For a simple solution, that interface often has used a very large value blocking capacitor (220µF) to limit tilt, or SAG, across the frames. One approach to creating a very low high-pass pole location using much lower capacitor values is shown in Figure 76. DC LEVEL-SHIFTING Figure 74 shows the general form of Figure 73 as a DC-coupled noninverting amplifier that level-shifts the input up to accommodate the desired output 24 Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 Normalized Gain (dB) This circuit gives a voltage gain of 2 at the output pin with a high-pass pole at 8Hz. Given the 150Ω load, a simple blocking capacitor approach would require a 133µF value. The two much lower valued capacitors give this same low-pass pole using this simple SAG correction circuit of Figure 76. The input is shifted slightly positive in Figure 76 using the voltage divider from the positive supply. This gives about a 200mV input DC offset that will show up at the output pin as a 400mV DC offset when the DAC output is at zero current during the sync tip portion of the video signal. This acts to hold the output in its linear operating region. This will pass on any power-supply noise to the output with a gain of approximately –20dB, so good supply decoupling is recommended on the power-supply pin. Figure 75 shows the frequency response for the circuit of Figure 76. This plot shows the 8Hz low-frequency high-pass pole and a high-end cutoff at approximately 100MHz. +5V 3 0 −3 −6 −9 − 12 − 15 − 18 − 21 1 10 102 103 104 105 106 107 108 109 Frequency (Hz) Figure 75. Video Line Driver Response to Matched Load 1.87k Ω Video DAC 1/2 OPA2830 47µ F 75Ω VO 75Ω Load 78.7 Ω 845Ω 325Ω 528Ω 22µ F 650Ω Figure 76. Video Line Driver with SAG Correction Submit Documentation Feedback 25 OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 NONINVERTING AMPLIFIER WITH REDUCED PEAKING Figure 77 shows a noninverting amplifier that reduces peaking at low gains. The resistor RC compensates the OPA2830 to have higher Noise Gain (NG), which reduces the AC response peaking (typically 4dB at G = +1 without RC) without changing the DC gain. VIN needs to be a low impedance source, such as an op amp. RT VIN RC 1/2 OPA2830 VOUT +5V RT = RF = 20.0Ω and RC = 40.2Ω (do not use RG). This gives a noise gain of 2, so the response will be similar to the Characteristics Plots with G = +2 giving less peaking. SINGLE-SUPPLY ACTIVE FILTER The OPA2830 operating on a single +3V or +5V supply lends itself well to high-frequency active filter designs. The key additional requirement is to establish the DC operating point of the signal near the supply midpoint for highest dynamic range. Figure 78 shows an example design of a 1MHz low-pass Butterworth filter using the Sallen-Key topology. Both the input signal and the gain setting resistor are AC-coupled using 0.1µF blocking capacitors (actually giving bandpass response with the low-frequency pole set to 32kHz for the component values shown). This allows the midpoint bias formed by the two 1.87kΩ resistors to appear at both the input and output pins. The midband signal gain is set to +4 (12dB) in this case. The capacitor to ground on the noninverting input is intentionally designed at a higher value to dominate input parasitic terms. At a gain of +4, the OPA2830 on a single supply will show 30MHz small- and large-signal bandwidth. The filter resistor values have been slightly adjusted to account for this limited bandwidth in the amplifier stage. Tests of this circuit show a precise 1MHz, –3dB point with a maximally-flat passband (above the 32kHz AC-coupling corner), and a maximum stop band attenuation of 36dB at the amplifier's –3dB bandwidth of 30MHz. RG RF Figure 77. Compensated Noninverting Amplifier The Noise Gain can be calculated as follows: R G1 + 1 ) F RG G2 + 1 ) NG + G 1 R T ) GF 1 R RC G2 A unity-gain buffer can be designed by selecting +5V 100pF 0.1µ F VI 1.87kΩ 150pF 1.87kΩ 137Ω 432Ω 1/2 OPA2830 4V I 1MHz, 2nd−Order Butterworth Filter 1.5kΩ 500Ω 0.1 µ F Figure 78. Single-Supply, High-Frequency Active Filter 26 Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 DIFFERENTIAL LOW-PASS ACTIVE FILTERS The dual OPA2830 offers an easy means to implement low-power differential active filters. On a single supply, one way to implement a 2nd-order, low-pass filter is shown in Figure 79. This circuit provides a net differential gain of 1 with a precise 5MHz Butterworth response. The signal is AC-coupled (giving a high-pass pole at low frequencies) with the DC operating point for the circuit set by the unity-gain buffer—the BUF602. This buffer gives a very low output impedance to high frequencies to maintain accurate filter characteristics. If the source is a DC-coupled signal already biased into the operating range of the OPA2830 input CMR, these capacitors and the midpoint bias may be removed. To get the desired 5MHz cutoff, the input resistors to the filter is actually 119Ω. This is implemented in Figure 79 as the parallel combination of the two 238Ω resistors on each half of the differential input as part of the DC biasing network. If the BUF602 is removed, these resistors should be collapsed back to a single 119Ω input resistor. unity-gain filter characteristic from input to output. The filter design shown here has also adjusted the resistor values slightly from an ideal analysis to account for the 100MHz bandwidth in the amplifier stages. The filter capacitors at the noninverting inputs are shown as two separate capacitors to ground. While it is certainly correct to collapse these two capacitors into a single capacitor across the two inputs (which would be 50pF for this circuit) to get the same differential filtering characteristic, tests have shown two separate capacitors to a low impedance point act to attenuate the common-mode feedback present in this circuit giving more stable operation in actual implementation. Figure 80 shows the frequency response for the filter of Figure 79. 0 −1 −2 Differential Gain (dB) −3 −4 −5 −6 −7 −8 −9 − 10 − 11 − 12 102 103 104 Frequency (Hz) 105 106 150pF +5V 0.1µF 238 Ω 506Ω 1/2 OPA2830 +5V 238Ω 5kΩ 100pF 750Ω VI 2.5V 0.1 µF 5kΩ Figure 80. 5MHz, 2nd-Order, Butterworth Low-Pass Filter VO BUF602 1500Ω 750Ω 238Ω 100pF 1/2 OPA2830 HIGH-PASS FILTERS Another approach to mid-supply biasing is shown in Figure 81. This method uses a bypassed divider network in place of the buffer used in Figure 79. The impedance is set by the parallel combination of the resistors forming the divider network, but as frequency increases it looks more and more like a short due to the capacitor. Generally, the capacitor value needs to be two to three orders of magnitude greater than the filter capacitors shown for the circuit to work properly. 0.1 µF 238 Ω 506Ω 150pF Figure 79. Single-Supply, 2nd-Order, Low-Pass Sallen-Key Filter Implementing the DC bias in this way also attenuates the differential signal by half. This is recovered by setting the amplifier gain at 2V/V to get a net Submit Documentation Feedback 27 OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 +VS +5V 374Ω 2.2nF 2.2nF 1/2 OPA2830 750Ω 2kΩ 1µ F compliance voltage other than ground for operation, the appropriate voltage level may be applied to the noninverting input of the OPA2830. The DC gain for this circuit is equal to RF. At high frequencies, the DAC output capacitance (CD in Figure 83) will produce a zero in the noise gain for the OPA2830 that may cause peaking in the closed-loop frequency response. CF is added across RF to compensate for this noise gain peaking. To achieve a flat transimpedance frequency response, the pole in each feedback network should be set to: VO VI VS/2 2kΩ 750Ω 1/2 OPA2830 1 + 2pR FCF GBP 4pR FC D which will give approximately: f *3dB + GBP 2pRFC D a cutoff frequency f–3dB of 2.2nF 2.2nF 374Ω +5V Figure 81. 138kHz, 2nd-Order, High-Pass Filter 2.5kΩ Results showing the frequency response for the circuit of Figure 81 is shown in Figure 82. 3 High−Speed DAC 2.5kΩ 1/2 OPA2830 VO = IO R F RF1 CF1 0 IO Gain (dB) −3 CD1 RF2 −6 −9 − 12 0.01 − IO CD2 CF2 +5V 0.1 Frequency (MHz) 1 10 2.5kΩ 1/2 OPA2830 − VO = − IO R F Figure 82. Frequency Response for the Filter of Figure 81 2.5kΩ GBP →Gain Bandwidth Product (Hz) for the OPA2830 HIGH-PERFORMANCE DAC TRANSIMPEDANCE AMPLIFIER High-frequency video Digital-to-Analog Converters (DACs) can sometimes benefit from a low distortion output amplifier to retain their SFDR performance into real-world loads. Figure 83 shows a differential output drive implementation. The diagram shows the signal output current(s) connected into the virtual ground summing junction(s) of the OPA2830, which is set up as a transimpedance stage or I-V converter. If the DAC requires that its outputs terminate to a 28 Figure 83. High-Speed DAC—Differential Transimpedance Amplifier Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 DESIGN-IN TOOLS Demonstration Fixtures Two printed circuit boards (PCBs) are available to assist in the initial evaluation of circuit performance using the OPA2830 in its two package options. Both of these are offered free of charge as unpopulated PCBs, delivered with a user's guide. The summary information for these fixtures is shown in Table 1. Table 1. Demonstration Fixtures by Package PRODUCT OPA2830ID OPA2830IDGK PACKAGE SO-8 MSOP-8 ORDERING NUMBER DEM-OPA-SO-2A DEM-OPA-MSOP-2A LITERATURE NUMBER SBOU003 SBOU004 A good rule of thumb is to target the parallel combination of RF and RG (see Figure 72) to be less than about 400Ω. The combined impedance RF || RG interacts with the inverting input capacitance, placing an additional pole in the feedback network, and thus a zero in the forward response. Assuming a 2pF total parasitic on the inverting node, holding RF || RG < 400Ω will keep this pole above 200MHz. By itself, this constraint implies that the feedback resistor RF can increase to several kΩ at high gains. This is acceptable as long as the pole formed by RF and any parasitic capacitance appearing in parallel is kept out of the frequency range of interest. In the inverting configuration, an additional design consideration must be noted. RG becomes the input resistor and therefore the load impedance to the driving source. If impedance matching is desired, RG may be set equal to the required termination value. However, at low inverting gains, the resultant feedback resistor value can present a significant load to the amplifier output. For example, an inverting gain of 2 with a 50Ω input matching resistor (= RG) would require a 100Ω feedback resistor, which would contribute to output loading in parallel with the external load. In such a case, it would be preferable to increase both the RF and RG values, and then achieve the input matching impedance with a third resistor to ground (see Figure 84). The total input impedance becomes the parallel combination of RG and the additional shunt resistor. The demonstration fixtures can be requested at the Texas Instruments web site (www.ti.com) through the OPA2830 product folder. Macromodel and Applications Support Computer simulation of circuit performance using SPICE is often a quick way to analyze the performance of the OPA2830 and its circuit designs. This is particularly true for video and RF amplifier circuits where parasitic capacitance and inductance can play a major role on circuit performance. A SPICE model for the OPA2830 is available through the TI web page (www.ti.com). The applications department is also available for design assistance. These models predict typical small signal AC, transient steps, DC performance, and noise under a wide variety of operating conditions. The models include the noise terms found in the electrical specifications of the data sheet. These models do not attempt to distinguish between the package types in their small-signal AC performance. BANDWIDTH vs GAIN: NONINVERTING OPERATION Voltage-feedback op amps exhibit decreasing closed-loop bandwidth as the signal gain is increased. In theory, this relationship is described by the Gain Bandwidth Product (GBP) shown in the specifications. Ideally, dividing GBP by the noninverting signal gain (also called the Noise Gain, or NG) will predict the closed-loop bandwidth. In practice, this only holds true when the phase margin approaches 90°, as it does in high-gain configurations. At low gains (increased feedback factors), most amplifiers will exhibit a more complex response with lower phase margin. The OPA2830 is compensated to give a slightly peaked response in a noninverting gain of 2 (see Figure 72). This results in a typical gain of +2 bandwidth of 105MHz, far exceeding that predicted by dividing the 105MHz GBP by 2. Increasing the gain will cause the phase margin to approach 90° and the bandwidth to more closely approach the predicted value of (GBP/NG). At a gain of +10, the 10MHz bandwidth shown in the Electrical Characteristics agrees with that predicted using the simple formula and the typical GBP of 105MHz. OPERATING SUGGESTIONS OPTIMIZING RESISTOR VALUES Since the OPA2830 is a unity-gain stable, voltage-feedback op amp, a wide range of resistor values may be used for the feedback and gain setting resistors. The primary limits on these values are set by dynamic range (noise and distortion) and parasitic capacitance considerations. For a noninverting unity-gain follower application, the feedback connection should be made with a direct short. Below 200Ω, the feedback network will present additional output loading which can degrade the harmonic distortion performance of the OPA2830. Above 1kΩ, the typical parasitic capacitance (approximately 0.2pF) across the feedback resistor may cause unintentional band limiting in the amplifier response. Submit Documentation Feedback 29 OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 Frequency response in a gain of +2 may be modified to achieve exceptional flatness simply by increasing the noise gain to 3. One way to do this, without affecting the +2 signal gain, is to add an 2.55kΩ resistor across the two inputs, as shown in Figure 77. A similar technique may be used to reduce peaking in unity-gain (voltage follower) applications. For example, by using a 750Ω feedback resistor along with a 750Ω resistor across the two op amp inputs, the voltage follower response will be similar to the gain of +2 response of Figure 71. Further reducing the value of the resistor across the op amp inputs will further dampen the frequency response due to increased noise gain. The OPA2830 exhibits minimal bandwidth reduction going to single-supply (+5V) operation as compared with ±5V. This minimal reduction is because the internal bias control circuitry retains nearly constant quiescent current as the total supply voltage between the supply pins is changed. is that the gain resistor (RG) becomes part of the signal channel input impedance. If input impedance matching is desired (which is beneficial whenever the signal is coupled through a cable, twisted pair, long PC board trace, or other transmission line conductor), RG may be set equal to the required termination value and RF adjusted to give the desired gain. This is the simplest approach and results in optimum bandwidth and noise performance. However, at low inverting gains, the resulting feedback resistor value can present a significant load to the amplifier output. For an inverting gain of 2, setting RG to 50Ω for input matching eliminates the need for RM but requires a 100Ω feedback resistor. This configuration has the interesting advantage of the noise gain becoming equal to 2 for a 50Ω source impedance—the same as the noninverting circuits considered above. The amplifier output will now see the 100Ω feedback resistor in parallel with the external load. In general, the feedback resistor should be limited to the 200Ω to 1.5kΩ range. In this case, it is preferable to increase both the RF and RG values, as shown in Figure 84, and then achieve the input matching impedance with a third resistor (RM) to ground. The total input impedance becomes the parallel combination of RG and RM. The second major consideration, touched on in the previous paragraph, is that the signal source impedance becomes part of the noise gain equation and hence influences the bandwidth. For the example in Figure 84, the RM value combines in parallel with the external 50Ω source impedance (at high frequencies), yielding an effective driving impedance of 50Ω || 57.6Ω = 26.8Ω. This impedance is added in series with RG for calculating the noise gain. The resulting noise gain is 2.87 for Figure 84, as opposed to only 2 if RM could be eliminated as discussed above. The bandwidth will therefore be lower for the gain of –2 circuit of Figure 84 (NG = +2.87) than for the gain of +2 circuit of Figure 70. The third important consideration in inverting amplifier design is setting the bias current cancellation resistors on the noninverting input (a parallel combination of RT = 750Ω). If this resistor is set equal to the total DC resistance looking out of the inverting node, the output DC error, due to the input bias currents, will be reduced to (Input Offset Current) times RF. With the DC blocking capacitor in series with RG, the DC source impedance looking out of the inverting mode is simply RF = 750Ω for Figure 84. To reduce the additional high-frequency noise introduced by this resistor and power-supply feed-through, RT is bypassed with a capacitor. INVERTING AMPLIFIER OPERATION All of the familiar op amp application circuits are available with the OPA2830 to the designer. See Figure 84 for a typical inverting configuration where the I/O impedances and signal gain from Figure 70 are retained in an inverting circuit configuration. Inverting operation is one of the more common requirements and offers several performance benefits. It also allows the input to be biased at VS/2 without any headroom issues. The output voltage can be independently moved to be within the output voltage range with coupling capacitors, or bias adjustment resistors. +5V 0.1µ F 2RT 1.5kΩ 1/2 OPA2830 + 6.8µF 150Ω 0.1µF 2RT 1.5kΩ +VS 2 50Ω Source 0.1µF RG 374Ω RF 750Ω RM 57.6Ω Figure 84. AC-Coupled, G = –2 Example Circuit In the inverting configuration, three key design considerations must be noted. The first consideration 30 Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 OUTPUT CURRENT AND VOLTAGES The OPA2830 provides outstanding output voltage capability. For the +5V supply, under no-load conditions at +25°C, the output voltage typically swings closer than 90mV to either supply rail. The minimum specified output voltage and current specifications over temperature are set by worst-case simulations at the cold temperature extreme. Only at cold startup will the output current and voltage decrease to the numbers shown in the ensured tables. As the output transistors deliver power, their junction temperatures will increase, decreasing their VBEs (increasing the available output voltage swing) and increasing their current gains (increasing the available output current). In steady-state operation, the available output voltage and current will always be greater than that shown in the over-temperature specifications, since the output stage junction temperatures will be higher than the minimum specified operating ambient. DISTORTION PERFORMANCE The OPA2830 provides good distortion performance into a 150Ω load. Relative to alternative solutions, it provides exceptional performance into lighter loads and/or operating on a single +3V supply. Generally, until the fundamental signal reaches very high frequency or power levels, the 2nd-harmonic will dominate the distortion with a negligible 3rd-harmonic component. Focusing then on the 2nd-harmonic, increasing the load impedance improves distortion directly. Remember that the total load includes the feedback network; in the noninverting configuration (see Figure 72) this is sum of RF + RG, while in the inverting configuration, only RF needs to be included in parallel with the actual load. Running differentially suppresses the 2nd-harmonic, as shown in the differential typical characteristic curves. NOISE PERFORMANCE High slew rate, unity-gain stable, voltage-feedback op amps usually achieve their slew rate at the expense of a higher input noise voltage. The 9.2nV/√Hz input voltage noise for the OPA2830 however, is much lower than comparable amplifiers. The input-referred voltage noise and the two input-referred current noise terms (2.8pA/√Hz) combine to give low output noise under a wide variety of operating conditions. Figure 85 shows the op amp noise analysis model with all the noise terms included. In this model, all noise terms are taken to be noise voltage or current density terms in either nV/√Hz or pA/√Hz. ENI 1/2 OPA2830 IBN DRIVING CAPACITIVE LOADS One of the most demanding and yet very common load conditions for an op amp is capacitive loading. Often, the capacitive load is the input of an ADC—including additional external capacitance which may be recommended to improve ADC linearity. A high-speed, high open-loop gain amplifier like the OPA2830 can be very susceptible to decreased stability and closed-loop response peaking when a capacitive load is placed directly on the output pin. When the primary considerations are frequency response flatness, pulse response fidelity, and/or distortion, the simplest and most effective solution is to isolate the capacitive load from the feedback loop by inserting a series isolation resistor between the amplifier output and the capacitive load. The Typical Characteristic curves show the recommended RS versus capacitive load and the resulting frequency response at the load. Parasitic capacitive loads greater than 2pF can begin to degrade the performance of the OPA2830. Long PC board traces, unmatched cables, and connections to multiple devices can easily exceed this value. Always consider this effect carefully, and add the recommended series resistor as close as possible to the output pin (see the Board Layout Guidelines section). The criterion for setting this RS resistor is a maximum bandwidth, flat frequency response at the load. For a gain of +2, the frequency response at the output pin is already slightly peaked without the capacitive load, requiring relatively high values of RS to flatten the response at the load. Increasing the noise gain will also reduce the peaking (see Figure 77). RS EO ERS √ 4kTRS RF √ 4kTRF 4kT = 1.6E − 20J at 290_ K 4kT RG RG IBI Figure 85. Noise Analysis Model The total output spot noise voltage can be computed as the square root of the sum of all squared output noise voltage contributors. Equation 1 shows the general form for the output noise voltage using the terms shown in Figure 85: Submit Documentation Feedback 31 OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 2 2 EO + E NI ) I BNRS ) 4kTRS NG 2 ) I BIR F 2 ) 4kTRFNG (1) Dividing this expression by the noise gain (NG = (1 + RF/RG)) will give the equivalent input-referred spot noise voltage at the noninverting input, as shown in Equation 2: EN + ENI ) IBNR S ) 4kTRS ) 2 2 DC offsetting current into the inverting input node through resistor values that are much larger than the signal path resistors. This will insure that the adjustment circuit has minimal effect on the loop gain and hence the frequency response. THERMAL ANALYSIS Maximum desired junction temperature will set the maximum allowed internal power dissipation, as described below. In no case should the maximum junction temperature be allowed to exceed 150°C. Operating junction temperature (TJ) is given by TA + PD × θJA. The total internal power dissipation (PD) is the sum of quiescent power (PDQ) and additional power dissipated in the output stage (PDL) to deliver load power. Quiescent power is simply the specified no-load supply current times the total supply voltage across the part. PDL will depend on the required output signal and load; though, for resistive loads connected to mid-supply (VS/2), PDL is at a maximum when the output is fixed at a voltage equal to VS/4 or 3VS/4. Under this condition, PDL = VS2/(16 × RL), where RL includes feedback network loading. Note that it is the power in the output stage, and not into the load, that determines internal power dissipation. As a worst-case example, compute the maximum TJ using an OPA2830 (MSOP-8 package) in the circuit of Figure 72 operating at the maximum specified ambient temperature of +85°C and driving a 150Ω load at +2.5VDC on both outputs. P D + 10V 11.9mA ) 2 16 52 150W ø 1500W + 142mW IBIRF NG 2 ) 4kTRF NG (2) Evaluating these two equations for the circuit and component values shown in Figure 70 will give a total output spot noise voltage of 19.3nV/√Hz and a total equivalent input spot noise voltage of 9.65nV/√Hz. This is including the noise added by the resistors. This total input-referred spot noise voltage is not much higher than the 9.2nV/√Hz specification for the op amp voltage noise alone. DC ACCURACY AND OFFSET CONTROL The balanced input stage of a wideband voltage-feedback op amp allows good output DC accuracy in a wide variety of applications. The power-supply current trim for the OPA2830 gives even tighter control than comparable products. Although the high-speed input stage does require relatively high input bias current (typically 5µA out of each input terminal), the close matching between them may be used to reduce the output DC error caused by this current. This is done by matching the DC source resistances appearing at the two inputs. Evaluating the configuration of Figure 72 (which has matched DC input resistances), using worst-case +25°C input offset voltage and current specifications, gives a worst-case output offset voltage equal to: • (NG = noninverting signal gain at DC) • ±(NG × VOS(MAX)) + (RF × IOS(MAX)) • = ±(2 × 7.5mV) × (375Ω × 1.1µA) • = ±15.41mV A fine-scale output offset null, or DC operating point adjustment, is often required. Numerous techniques are available for introducing DC offset control into an op amp circuit. Most of these techniques are based on adding a DC current through the feedback resistor. In selecting an offset trim method, one key consideration is the impact on the desired signal path frequency response. If the signal path is intended to be noninverting, the offset control is best applied as an inverting summing signal to avoid interaction with the signal source. If the signal path is intended to be inverting, applying the offset control to the noninverting input may be considered. Bring the Maximum T J + ) 85 oC ) 0.142W 150 oC W + 106 oC Although this is still well below the specified maximum junction temperature, system reliability considerations may require lower ensured junction temperatures. The highest possible internal dissipation will occur if the load requires current to be forced into the output at high output voltages or sourced from the output at low output voltages. This puts a high current through a large internal voltage drop in the output transistors. BOARD LAYOUT GUIDELINES Achieving optimum performance with a high-frequency amplifier like the OPA2830 requires careful attention to board layout parasitics and external component types. Recommendations that will optimize performance include: a) Minimize parasitic capacitance to any AC ground for all of the signal I/O pins. Parasitic 32 Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 capacitance on the output and inverting input pins can cause instability: on the noninverting input, it can react with the source impedance to cause unintentional bandlimiting. To reduce unwanted capacitance, a window around the signal I/O pins should be opened in all of the ground and power planes around those pins. Otherwise, ground and power planes should be unbroken elsewhere on the board. b) Minimize the distance ( < 0.25") from the power-supply pins to high-frequency 0.1µF decoupling capacitors. At the device pins, the ground and power-plane layout should not be in close proximity to the signal I/O pins. Avoid narrow power and ground traces to minimize inductance between the pins and the decoupling capacitors. Each power-supply connection should always be decoupled with one of these capacitors. An optional supply decoupling capacitor (0.1µF) across the two power supplies (for bipolar operation) will improve 2nd-harmonic distortion performance. Larger (2.2µF to 6.8µF) decoupling capacitors, effective at lower frequency, should also be used on the main supply pins. These may be placed somewhat farther from the device and may be shared among several devices in the same area of the PC board. c) Careful selection and placement of external components will preserve the high-frequency performance. Resistors should be a very low reactance type. Surface-mount resistors work best and allow a tighter overall layout. Metal film or carbon composition axially-leaded resistors can also provide good high-frequency performance. Again, keep their leads and PC board traces as short as possible. Never use wire-wound type resistors in a high-frequency application. Since the output pin and inverting input pin are the most sensitive to parasitic capacitance, always position the feedback and series output resistor, if any, as close as possible to the output pin. Other network components, such as noninverting input termination resistors, should also be placed close to the package. Where double-side component mounting is allowed, place the feedback resistor directly under the package on the other side of the board between the output and inverting input pins. Even with a low parasitic capacitance shunting the external resistors, excessively high resistor values can create significant time constants that can degrade performance. Good axial metal film or surface-mount resistors have approximately 0.2pF in shunt with the resistor. For resistor values > 1.5kΩ, this parasitic capacitance can add a pole and/or zero below 500MHz that can effect circuit operation. Keep resistor values as low as possible consistent with load driving considerations. The 750Ω feedback used in the Typical Characteristics is a good starting point for design. d) Connections to other wideband devices on the board may be made with short direct traces or through onboard transmission lines. For short connections, consider the trace and the input to the next device as a lumped capacitive load. Relatively wide traces (50mils to 100mils) should be used, preferably with ground and power planes opened up around them. Estimate the total capacitive load and set RS from the typical characteristic curve Recommended RS vs Capacitive Load. Low parasitic capacitive loads (< 5pF) may not need an RS since the OPA2830 is nominally compensated to operate with a 2pF parasitic load. Higher parasitic capacitive loads without an RS are allowed as the signal gain increases (increasing the unloaded phase margin). If a long trace is required, and the 6dB signal loss intrinsic to a doubly-terminated transmission line is acceptable, implement a matched impedance transmission line using microstrip or stripline techniques (consult an ECL design handbook for microstrip and stripline layout techniques). A 50Ω environment is normally not necessary onboard, and in fact, a higher impedance environment will improve distortion as shown in the distortion versus load plots. With a characteristic board trace impedance defined (based on board material and trace dimensions), a matching series resistor into the trace from the output of the OPA2830 is used as well as a terminating shunt resistor at the input of the destination device. Remember also that the terminating impedance will be the parallel combination of the shunt resistor and the input impedance of the destination device; this total effective impedance should be set to match the trace impedance. If the 6dB attenuation of a doubly-terminated transmission line is unacceptable, a long trace can be series-terminated at the source end only. Treat the trace as a capacitive load in this case and set the series resistor value as shown in the typical characteristic curve Recommended RS vs Capacitive Load. This will not preserve signal integrity as well as a doubly-terminated line. If the input impedance of the destination device is low, there will be some signal attenuation due to the voltage divider formed by the series output into the terminating impedance. e) Socketing a high-speed part is not recommended. The additional lead length and pin-to-pin capacitance introduced by the socket can create an extremely troublesome parasitic network which can make it almost impossible to achieve a smooth, stable frequency response. Best results are obtained by soldering the OPA2830 onto the board. Submit Documentation Feedback 33 OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 INPUT AND ESD PROTECTION The OPA2830 is built using a very high-speed complementary bipolar process. The internal junction breakdown voltages are relatively low for these very small geometry devices. These breakdowns are reflected in the Absolute Maximum Ratings table. All device pins are protected with internal ESD protection diodes to the power supplies, as shown in Figure 86. +VCC These diodes provide moderate protection to input overdrive voltages above the supplies as well. The protection diodes can typically support 30mA continuous current. Where higher currents are possible (that is, in systems with ±15V supply parts driving into the OPA2830), current-limiting series resistors should be added into the two inputs. Keep these resistor values as low as possible, since high values degrade both noise performance and frequency response. External Pin Internal Circuitry − VCC Figure 86. Internal ESD Protection 34 Submit Documentation Feedback OPA2830 www.ti.com SBOS309C – AUGUST 2004 – REVISED MARCH 2006 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from B Revision (February 2006) to C Revision ............................................................................................ Page • Changed Differential Input Voltage to ±2.5V from ±1.2V...................................................................................................... 2 Submit Documentation Feedback 35 PACKAGE OPTION ADDENDUM www.ti.com 6-Nov-2006 PACKAGING INFORMATION Orderable Device OPA2830ID OPA2830IDG4 OPA2830IDGKR OPA2830IDGKRG4 OPA2830IDGKT OPA2830IDGKTG4 OPA2830IDR OPA2830IDRG4 (1) Status (1) ACTIVE ACTIVE ACTIVE ACTIVE ACTIVE ACTIVE ACTIVE ACTIVE Package Type SOIC SOIC MSOP MSOP MSOP MSOP SOIC SOIC Package Drawing D D DGK DGK DGK DGK D D Pins Package Eco Plan (2) Qty 8 8 8 8 8 8 8 8 100 100 Green (RoHS & no Sb/Br) Green (RoHS & no Sb/Br) Lead/Ball Finish CU NIPDAU CU NIPDAU CU NIPDAU CU NIPDAU CU NIPDAU CU NIPDAU CU NIPDAU CU NIPDAU MSL Peak Temp (3) Level-2-260C-1 YEAR Level-2-260C-1 YEAR Level-2-260C-1 YEAR Level-2-260C-1 YEAR Level-2-260C-1 YEAR Level-2-260C-1 YEAR Level-2-260C-1 YEAR Level-2-260C-1 YEAR 2500 Green (RoHS & no Sb/Br) 2500 Green (RoHS & no Sb/Br) 250 250 Green (RoHS & no Sb/Br) Green (RoHS & no Sb/Br) 2500 Green (RoHS & no Sb/Br) 2500 Green (RoHS & no Sb/Br) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 11-Mar-2008 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing MSOP MSOP SOIC DGK DGK D 8 8 8 SPQ Reel Reel Diameter Width (mm) W1 (mm) 330.0 180.0 330.0 12.4 12.4 12.4 A0 (mm) B0 (mm) K0 (mm) P1 (mm) 8.0 8.0 8.0 W Pin1 (mm) Quadrant 12.0 12.0 12.0 Q1 Q1 Q1 OPA2830IDGKR OPA2830IDGKT OPA2830IDR 2500 250 2500 5.3 5.3 6.4 3.4 3.4 5.2 1.4 1.4 2.1 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 11-Mar-2008 *All dimensions are nominal Device OPA2830IDGKR OPA2830IDGKT OPA2830IDR Package Type MSOP MSOP SOIC Package Drawing DGK DGK D Pins 8 8 8 SPQ 2500 250 2500 Length (mm) 346.0 184.0 346.0 Width (mm) 346.0 184.0 346.0 Height (mm) 29.0 50.0 29.0 Pack Materials-Page 2 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. 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