THS4302EVM

THS4302 www.ti.com SLOS403H – OCTOBER 2002 – REVISED AUGUST 2006 WIDEBAND FIXED-GAIN AMPLIFIER FEATURES APPLICATIONS • • • • • • • • • • • • 1 2 • • Fixed-Gain Amplifier, 5 V/V (14 dB) Wide Bandwidth: 2.4 GHz High Slew Rate: 5500 V/μs Low Total Input Referred Noise: 2.8 nV/√Hz Low Distortion – HD3: -86 dBc at 30 MHz – HD3: -81 dBc at 70 MHz – IMD3: -88 dBc at 100 MHz – OIP3: 39 dBm at 100 MHz – IMD3: -73 dBc at 300 MHz – OIP3: 32 dBm at 300 MHz High Output Drive: ±180 mA Power Supply Voltage: 3 V or 5 V Wideband Signal Processing Wireless Transceivers IF Amplifier ADC Preamplifier DAC Output Buffers Test, Measurement, and Instrumentation Medical and Industrial Imaging DESCRIPTION The THS4302 device is a wideband, fixed-gain amplifier that offers high bandwidth, high slew rate, low noise, and low distortion. This combination of specifications enables analog designers to transcend current performance limitations and process analog signals at much higher speeds than previously possible with closed-loop, complementary amplifier designs. This device is offered in a 16-pin leadless package and incorporates a power-down mode for quiescent power savings. APPLICATION CIRCUIT VS+ SMALL SIGNAL FREQUENCY RESPONSE 16 + 47 pF 0.1 µF 14 30.1 Ω 12 Rf Rg 50 Ω Source _ + VI VO THS4302 49.9 Ω 100 Ω Small Signal Gain - dB FB 22 µF 10 8 6 4 2 VS- VO = 200 mV RL = 100 Ω VS = 5 V 0 10 M 100 M 1G 10 G f - Frequency - Hz + 22 µF FB 47 pF 0.1 µF 30.1 Ω FB = Ferrite Bead 1 2 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. PowerPAD is a trademark of Texas Instruments. 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 © 2002–2006, Texas Instruments Incorporated THS4302 www.ti.com SLOS403H – OCTOBER 2002 – REVISED AUGUST 2006 These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. ABSOLUTE MAXIMUM RATING over operating free-air temperature range unless otherwise noted (1) UNIT Supply voltage, VS 6V Input voltage, VI ±VS Output current, IO 200 mA Continuous power dissipation See Dissipation Rating Table Maximum junction temperature, TJ 150°C Maximum junction temperature, continuous operation, long term reliability, TJ (2) 125°C Storage temperature range, Tstg -65°C to 150°C Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds (1) (2) 300°C The absolute maximum temperature under any condition is limited by the constraints of the silicon process. 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 implied. The maximum junction temperature for continuous operation is limited by package constraints. Operation above this temperature may result in reduced reliability and/or lifetime of the device. RECOMMENDED OPERATING CONDITIONS MIN MAX ±1.5 ±2.5 3 5 VS- +1 VS+ -1 Dual supply Supply voltage, VCC (VS+ and VS-) Single supply Common-mode input voltage range UNIT V V PACKAGE DISSIPATION RATINGS (1) (2) (3) PACKAGE θJC(°C/W) θJA(°C/W) (1) RGT (16) (3) 2.4 39.5 POWER RATING (2) TA ≤ 25°C TA = 25°C 3.16 1.65 W This data was taken using the JEDEC standard High-K test PCB. Power rating is determined with a junction temperature of 125°C. This is the point where distortion starts to substantially increase. Thermal management of the final PCB should strive to keep the junction temperature at or below 125°C for best performance and long term reliability. The THS4302 device may incorporate a PowerPAD™ on the underside of the chip. This acts as a heatsink and must be connected to a thermally dissipative plane for proper power dissipation. Failure to do so may result in exceeding the maximum junction temperature which can permanently damage the device. See TI technical brief SLMA002 and SLMA004 for more information about utilizing the PowerPAD thermally enhanced package. AVAILABLE OPTIONS INTERNAL FIXED GAIN RESISTOR VALUES (+5) (1) 2 PACKAGED DEVICES RG RF THS4302RGTT 50 Ω 200 Ω THS4302RGTR PACKAGE TYPE (1) Leadless (RGT-16) TRANSPORTATION MEDIA, QUANTITY Tape and Reel, 250 Tape and Reel, 3000 The PowerPAD is electrically isolated from all other pins. Submit Documentation Feedback Copyright © 2002–2006, Texas Instruments Incorporated Product Folder Link(s): THS4302 THS4302 www.ti.com SLOS403H – OCTOBER 2002 – REVISED AUGUST 2006 PIN ASSIGNMENTS NC V IN− 16 15 14 13 12 2 11 3 10 Rg 1 Rf VS− V IN+ PD RGT PACKAGE TOP VIEW 4 5 6 7 8 VS+ 9 VOUT NC = No connect ELECTRICAL CHARACTERISTICS THS4302 (Gain = +5 V/V) Specifications: VS = 5 V, RL = 100 Ω, (unless otherwise noted) TYP PARAMETER TEST CONDITIONS 25°C OVERTEMPERATURE 25°C 0°C to 70°C -40°C to 85°C UNITS MIN/ TYP/ MAX GHz Typ AC PERFORMANCE Small signal bandwidth G = +5, VO = 200 mVRMS 2.4 12 GHz Typ Full-power bandwidth G = +5, VO = 2 Vpp 875 MHz Typ Slew rate G = +5, VO = 2 V Step 5500 V/μs Min RL = 100 Ω -66 dBc RL = 1 kΩ -75 dBc RL = 100 Ω -81 dBc RL = 1 kΩ -85 dBc fc = 100 MHz -88 dBc Gain bandwidth product Harmonic distortion Second harmonic distortion G = +5, VO = 1 VPP, f = 70 MHz Third harmonic distortion Typ Typ Third order intermoduation (IMD3) VO = 1 VPP envelope, 200 kHz tone spacing fc = 300 MHz -73 dBc Third order output intercept (OIP3) VO = 1 VPP, 200 kHz fc = 100 MHz tone spacing fc = 300 MHz 39 dBm 32 dBm Total input referred noise f = 1 MHz 2.8 nV/√Hz Typ 16 dB Typ Noise figure Typ Typ DC PERFORMANCE Voltage gain VI = ±50 mV, VCM = 2.5 V Input offset voltage VCM = 2.5 V Average offset voltage drift Input bias current Average bias current drift 5 4.95 4.95 4.95 V/V Min 5 5.05 5.05 5.05 V/V Max 2 4.25 5.25 5.25 mV Max ±20 ±20 μV/°C Typ VCM = 2.5 V VCM = 2.5 V VCM = 2.5 V 7 10 13 15 μA Max ±55 ±55 nA/°C Typ Submit Documentation Feedback Copyright © 2002–2006, Texas Instruments Incorporated Product Folder Link(s): THS4302 3 THS4302 www.ti.com SLOS403H – OCTOBER 2002 – REVISED AUGUST 2006 ELECTRICAL CHARACTERISTICS (continued) THS4302 (Gain = +5 V/V) Specifications: VS = 5 V, RL = 100 Ω, (unless otherwise noted) TYP PARAMETER TEST CONDITIONS OVERTEMPERATURE 25°C 25°C 0°C to 70°C -40°C to 85°C UNITS MIN/ TYP/ MAX INPUT CHARACTERISTICS Common-mode input range 0.5/4.5 1/4 1.1/3.9 1.2/3.8 V Min Common-mode rejection ratio VCM = 2 V to 3 V 60 52 50 50 dB Min Input resistance Noninverting input 1.6 MΩ Typ Input capacitance Noninverting input 1 pF Max OUTPUT CHARACTERISTICS Output voltage swing 1/4 1.1/3.9 1.2/3.8 1.2/3.8 V Min Min Output current (sourcing) RL = 5 Ω 180 170 165 160 mA Output current (sinking) RL = 5 Ω 180 170 165 160 mA Min Output impedance f = 10 MHz 0.2 Ω Typ POWER SUPPLY Operating voltage 5 5.5 5.5 5.5 V Max Maximum quiescent current 37 42 46 48 mA Max Minimum quiescent current 37 32 29 26 mA Min Power supply rejection ratio (PSRR +) VS+ = 5 V to 4.5 V, VS- = 0 V 60 54 52 51 dB Min Power supply rejection ratio (PSRR -) VS+ = 5 V, VS- = 0 V to 0.5 V 75 65 64 62 dB Min PD = 0 V 1.1 1.2 mA Max POWER-DOWN CHARACTERISTICS Maximum power-down current 0.8 1.0 Power-on voltage threshold 1.1 1.5 V Min Power-down voltage threshold 1.1 0.9 V Max Turnon time delay, td(on) 50% of final value 6 μs Typ Turnoff time delay, td(off) 50% of final value 5 μs Typ 100 kΩ Typ 250 Ω Typ Input impedance Output impedance 4 f = 100 kHz Submit Documentation Feedback Copyright © 2002–2006, Texas Instruments Incorporated Product Folder Link(s): THS4302 THS4302 www.ti.com SLOS403H – OCTOBER 2002 – REVISED AUGUST 2006 TYPICAL CHARACTERISTICS Table of Graphs (5 V) FIGURE S-Parameter vs Frequency 1 Small signal frequency response 2 Large signal frequency response 3 Slew rate vs Output voltage 4 Harmonic distortion vs Frequency 5, 6, 7, 8 Harmonic distortion vs Output voltage swing 9 Second-order intermodulation distortion vs Frequency 10 Second-order intercept point vs Frequency 11 Third order intermodulation distortion vs Frequency 12 Third-order intercept point vs Frequency 13 Voltage and current noise vs Frequency 14 Settling time 15, 16 Quiescent current vs Supply voltage 17 Output voltage vs Load resistance 18 Capacitive load frequency response 19 Gain vs Case temperature 20 Rejection ratios vs Frequency 21 Rejection ratios vs Case temperature 22 Common-mode rejection ratio vs Input common-mode range 23 Input offset voltage vs Case temperature 24 Positive input bias current vs Case temperature 25 Small signal transient response 26 Large signal transient response 27 Overdrive recovery 28 Closed-loop output impedance vs Frequency 29 Power-down quiescent current vs Supply voltage 30 Power-down output impedance vs Frequency 31 Turnon and turnoff delay times 32 Power-down S-Parameter vs Frequency 33 Table of Graphs (3 V) FIGURE Small signal frequency response 34 Large signal frequency response 35 Slew rate vs Output voltage 36 Output voltage vs Load resistance 37 Capacitive load frequency response 38 Gain vs Case temperature 39 S - Parameter vs Frequency 40 Input offset voltage vs Case temperature 41 Positive input bias current vs Case temperature 42 Overdrive recovery 43 Submit Documentation Feedback Copyright © 2002–2006, Texas Instruments Incorporated Product Folder Link(s): THS4302 5 THS4302 www.ti.com SLOS403H – OCTOBER 2002 – REVISED AUGUST 2006 Typical Test Data S-Parameter (Measured using standard THS4302EVM, edge number 6443548, with VS = 5 V in a 50-Ω test system) Frequency MHz S11 (dB) S11 (Ang) S21 (dB) S21 (Ang) S12 (dB) S12 (Ang) S22 (dB) 1 -55.86328 -3.728516 14.10889 -0.093384 -96.26953 20.78809 -70.32422 S22 (Ang) 122.5 2 -55.75781 -4.832764 14.11621 -0.109863 -98.18359 -120.6758 -65.65234 97.16016 10 -53.0293 -29.01563 14.11035 -0.350189 -78.10156 121.2148 -52.01953 73.91406 50 -42.92383 -82.44141 14.16309 -1.682312 -61.82813 75 -45.27539 142.0391 100 -37.35156 -97.42188 14.34766 -4.422119 -56.37891 61.26367 -31.04981 115.4414 150 -35.64258 -105.9063 14.38428 -7.657471 -54.44336 53.0957 -26.75098 98.26172 200 -33.27344 -111.1133 14.42041 -10.49512 -53.72852 34.22656 -25.3418 85.07031 250 -32.18945 -114.2891 14.39209 -13.63135 -53.55273 31.70508 -24.14844 77.09766 300 -30.92578 -114.4297 14.40918 -17.17871 -53.94727 21.56934 -23.53613 72.94531 350 -30.29492 -113.9727 14.38477 -19.34375 -54.23828 19.45508 -22.99512 70.63281 400 -29.11816 -113.5313 14.38184 -23.08594 -55.13281 16.29395 -22.13379 72.0625 450 -28.44141 -116 14.35645 -25.62305 -56.33594 14.38232 -21.45215 71.90234 500 -27.50977 -114.082 14.36035 -28.69922 -58.48828 12.0708 -20.56641 74.21094 550 -26.51856 -112.25 14.3208 -32.48047 -63.26367 3.492187 -19.71094 74.85938 600 -26.01856 -113.6719 14.30713 -34.17773 -67.62109 27.33594 -19.2959 75.58984 700 -24.03613 -115.8984 14.23242 -39.5918 -68.02734 172.2422 -17.80078 77.79297 800 -21.97559 -117.4922 14.1665 -47.05664 -55.4082 171.0703 -15.81494 77.22266 900 -20.40137 -120.7305 14.11133 -51.92969 -50.38477 168.8125 -14.38965 76.04297 1000 -18.70313 -123.4023 14.06006 -57.80078 -46.64453 163.1016 -12.91406 73.89063 1250 -15.14893 -134.7031 13.93872 -75.02344 -40.19141 152.5313 -9.994141 65.77734 1500 -12.66602 -149.0625 13.74683 -88.4375 -35.73438 139.7109 -7.968018 55.74414 1750 -11.48975 -168.9922 12.97827 -110.2852 -31.94531 112.5 -6.750977 40.24414 2000 -11.68311 -169.8203 12.18066 -123.043 -34.46094 84.83984 -7.211182 31.3877 TYPICAL THS4302 CHARACTERISTICS (5 V) S-PARAMETER vs FREQUENCY 10 −20 50 Ω Source 50 Ω 50 Ω 50 Ω 16 14 14 S22 −40 S11 −60 S12 −70 16 VS = 5 V −30 −50 12 10 8 6 4 −80 2 −90 −100 RL = 100 Ω VO = 200 mV VS = 5 V 1M 10 M 100 M 1G f − Frequency − Hz 10 G 10 M 12 10 8 6 4 2 0 Figure 1. 6 LARGE SIGNAL FREQUENCY RESPONSE Large Signal Gain − dB S−Parameter − dB −10 − + Small Signal Gain − dB 0 SMALL SIGNAL FREQUENCY RESPONSE 100 M 1G f − Frequency − Hz Figure 2. Submit Documentation Feedback 10 G RL = 100 Ω VO = 2 V VS = 5 V 0 100 k 1M 10 M 100 M 1G 10 G f − Frequency − Hz Figure 3. Copyright © 2002–2006, Texas Instruments Incorporated Product Folder Link(s): THS4302 THS4302 www.ti.com SLOS403H – OCTOBER 2002 – REVISED AUGUST 2006 TYPICAL THS4302 CHARACTERISTICS (5 V) (continued) SLEW RATE vs OUTPUT VOLTAGE HARMONIC DISTORTION vs FREQUENCY −50 RL = 100 Ω VS = 5 V −60 Harmonic Distortion − dBc 5000 Fall 4000 Rise 3000 2000 −70 HD2 −80 −90 HD3 0 −80 HD2 −90 HD3 −100 0.5 1 1.5 2 −110 2.5 −110 1 10 f − Frequency − MHz VO − Output Voltage − VPP Figure 5. Figure 6. HARMONIC DISTORTION vs FREQUENCY HARMONIC DISTORTION vs FREQUENCY HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING −65 −70 HD2 −80 RL = 1 kΩ VO = 2 VPP VS = 5 V −60 Harmonic Distortion − dBc −60 −85 −50 −50 RL = 100 Ω VO = 2 VPP VS = 5 V −75 100 f − Frequency − MHz Figure 4. −50 −55 10 1 100 −70 HD3 −80 HD2 −90 HD3 HD2, f = 64 MHz −60 −65 −70 HD3, f = 64 MHz −75 HD2, f = 4 MHz −80 −85 −90 −95 −100 −90 10 1 RL = 100 Ω VS = 5 V −55 Harmonic Distortion − dBc 0 Harmonic Distortion − dBc −70 −100 1000 RL = 1 kΩ VO = 1 VPP VS = 5 V −60 100 HD3, f = 4 MHz −100 1 0 1 1.5 2 2.5 f − Frequency − MHz Figure 7. Figure 8. Figure 9. SECOND-ORDER INTERMODULATION DISTORTION vs FREQUENCY SECOND-ORDER OUTPUT INTERCEPT POINT vs FREQUENCY THIRD-ORDER INTERMODULATION DISTORTION vs FREQUENCY −50 100 −55 95 F2 − F1 90 −65 85 OIP 2 − dBm −60 −70 −75 F2 + F1 −80 −85 −95 −2.5V −50 −60 49.9 −65 80 Tone Spacing = 200 kHz To 50-Ω Load, Add 3dB to Refer To Amplifier Output 75 70 50 150 200 250 100 f − Frequency − MHz 300 Figure 10. VO = 1 VPP Envelope −75 −80 −90 F2 − F1 55 VO = 0.5 VPP Envelope −95 F2 + F1 50 0 VO = 2 VPP Envelope −70 −85 60 −100 RL = 100 Ω VS = 5 V 200 kHz Tone Spacing −55 50 Test Equipment 65 VS = 5 V RL = 100 Ω VO = 1 VPP Envelope Tone Spacing = 200 kHz −90 49.9 49.9 VO − Output Voltage Swing − VPP Test data measurement point +2.5V 50 Source 100 0.5 10 f − Frequency − MHz IMD 3 − dBc SR − Slew Rate − V/ µ s 6000 −50 RL = 100 Ω VO = 1 VPP VS = 5 V Harmonic Distortion − dBc 7000 IMD 2 − dBc HARMONIC DISTORTION vs FREQUENCY −100 0 50 100 150 200 250 f − Frequency − MHz Figure 11. 300 10 100 f − Frequency − MHz Figure 12. Submit Documentation Feedback Copyright © 2002–2006, Texas Instruments Incorporated Product Folder Link(s): THS4302 1000 7 THS4302 www.ti.com SLOS403H – OCTOBER 2002 – REVISED AUGUST 2006 TYPICAL THS4302 CHARACTERISTICS (5 V) (continued) THIRD-ORDER OUTPUT INTERCEPT POINT vs FREQUENCY 50 Source 35 VO = 1 VPP Envelope 31 29 Tone Spacing = 200 kHz To 50-Ω Load, Add 3dB to Refer To Amplifier Output 27 10 10 In Vn 100 200 300 400 500 100 1k f − Frequency − MHz 0.2 50 0.2 0.4 0.6 0.8 t − Time − ns RL = 100 Ω f= 1 MHz VS = 5 V 2.5 2.25 2 1.75 Falling Edge 35 TA = −40°C 30 25 20 15 10 0 0.6 0.8 1 1.2 1.4 1.6 3.5 3 VS = 5 V TA = −40 to 85°C 2.5 2 1.5 1 0.5 5 0.2 0.4 0 VS − Supply Voltage − V 10 100 RL − Load Resistance − Ω Figure 16. Figure 17. Figure 18. CAPACITIVE LOAD FREQUENCY RESPONSE GAIN vs CASE TEMPERATURE REJECTION RATIOS vs FREQUENCY 2.5 t − Time − ns 3 3.5 4 4.5 1 5 14.02 1 R(ISO) = 24.9 Ω, CL = 10 pF 0.5 1.2 4 TA = 25°C VO − Output Voltage − V 3 1 4.5 TA = 85°C 40 2.75 1000 70 PSRR+ 60 14 0 VS = 5 V Gain −dB −0.5 R(ISO) = 8 Ω, CL = 100 pF −1.5 −2.5 0 5 45 Quiescent Current − mA VO − Output Voltage − V 1.75 SETTLING TIME 1.25 Normalized Gain − dB 1 10 M 1M OUTPUT VOLTAGE vs LOAD RESISTANCE 1.5 R(ISO) = 12.1 Ω, CL = 47 pF 13.98 13.96 50 CMRR 40 30 20 13.94 10 VS = 5 V VS = 5 V −3 10 M 8 10 k 100 k f − Frequency − Hz QUIESCENT CURRENT vs SUPPLY VOLTAGE 3.5 3.25 −2 Falling Edge Figure 15. Rising Edge −1 2.25 Figure 14. 3.75 0 2.5 Figure 13. 4 1 0.2 RL = 100 Ω f= 1 MHz VS = 5 V 2.75 2 1 0 3 Rejection Ratios − dB 25 Hz 37 RL = 100 Ω VS = 5 V I n − Current Noise − pA/ 49.9 −2.5V 33 Hz 39 Rising Edge Vn − Voltage Noise − nV/ 50 Test Equipment 49.9 SETTLING TIME 3.25 100 49.9 41 OIP 3 − dBm 100 Test data measurement point +2.5V VO − Output Voltage − V 43 VOLTAGE AND CURRENT NOISE vs FREQUENCY 100 M 1G 13.92 −40−30−20−10 0 10 20 30 40 50 60 70 80 90 f − Frequency − Hz Case Temperature − °C Figure 19. Figure 20. Submit Documentation Feedback 0 100 k 1M 10 M 100 M f − Frequency − Hz 1G Figure 21. Copyright © 2002–2006, Texas Instruments Incorporated Product Folder Link(s): THS4302 THS4302 www.ti.com SLOS403H – OCTOBER 2002 – REVISED AUGUST 2006 TYPICAL THS4302 CHARACTERISTICS (5 V) (continued) COMMON-MODE REJECTION RATIO vs INPUT COMMON-MODE RANGE PSRR− 75 65 CMMR 60 55 PSRR+ 50 45 VS = 5 V 40 −40−30−20−10 0 10 20 30 40 50 60 70 80 90 Case Temperature − °C VS = 5 V 60 50 40 30 20 10 VS = 5 V 0 −10 0 1 3 4 4 3 2 1 0 −40−30−20−10 0 10 20 30 40 50 60 70 80 90 5 VICR − Input Common-Mode Voltage Range − V Case Temperature − °C Figure 23. Figure 24. POSITIVE INPUT BIAS CURRENT vs CASE TEMPERATURE SMALL SIGNAL TRANSIENT RESPONSE LARGE SIGNAL TRANSIENT RESPONSE 2.65 4 10 2.6 3.5 8 2.55 6 2.5 4 2.45 2 2.4 2.35 0 −40−30−20−10 0 10 20 30 40 50 60 70 80 90 Case Temperature − °C VO − Output Voltage − V VS = 5 V RL = 100 Ω Input tr/tf = 60 ps VS = 5 V 3 2.5 2 RL = 100 Ω Input tr/tf = 60 ps VS = 5 V 1.5 0 2 4 6 8 1 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 t − Time − ns Figure 25. Figure 26. Figure 27. OVERDRIVE RECOVERY OUTPUT IMPEDANCE vs FREQUENCY POWER-DOWN QUIESCENT CURRENT vs SUPPLY VOLTAGE 5.5 100 3 1200 VS = 5 V 5 2.75 4 3.5 3 2.5 2.5 2 1.5 2.25 1 Output Impedance − Ω 4.5 VI − Input Voltage − V Single-Ended Output Voltage − V 2 5 Figure 22. 12 I IB+ − Positive Input Bias Current − µ A 6 70 Power-Down Quiescent Current − µ A Rejection Ratios − dB 70 INPUT OFFSET VOLTAGE vs CASE TEMPERATURE VOS − Input Offset Voltage − mV 80 CMRR − Common-Mode Rejection Ratio − dB REJECTION RATIOS vs CASE TEMPERATURE 10 1 0.5 0 2 −0.5 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 t − Time − µs Figure 28. 0.1 10 M 100 M 1G f − Frequency − Hz Figure 29. 10 G 1100 1000 900 TA = 85°C TA = 25°C 800 TA = −40°C 700 600 500 400 300 200 100 0 2.5 2.75 3 3.25 3.5 3.75 4 4.25 4.5 4.75 5 VS − Supply Voltage − V Figure 30. Submit Documentation Feedback Copyright © 2002–2006, Texas Instruments Incorporated Product Folder Link(s): THS4302 9 THS4302 www.ti.com SLOS403H – OCTOBER 2002 – REVISED AUGUST 2006 TYPICAL THS4302 CHARACTERISTICS (5 V) (continued) POWER-DOWN OUTPUT IMPEDANCE vs FREQUENCY 2 100 VS = 5 V 1M 10 M 100 M 1G f − Frequency − Hz 1 50 0 40 −1 30 −2 20 −3 RL = 100 Ω VS = 5 V 10 −4 0 −5 −10 −6 −15 0 15 30 45 t − Time − µs Figure 31. 60 10 VS = 5 V and 3 V 0 Powerdown S−Parameter − dB 3 70 V I − Input Voltage Level − V 80 60 I O − Output Current Level − mA Power-Down Output Impedance − Ω 1000 10 100 k POWER-DOWN S-PARAMETER vs FREQUENCY TURNON AND TURNOFF TIMES DELAY TIME RG −10 S22 RF C −20 − + −30 50 Ω −40 Source 50 Ω 50 Ω 50 Ω S11 −50 −60 −70 S12 −80 −90 −100 1M 75 10 M 100 M 1G 10 G f − Frequency − Hz Figure 32. Figure 33. TYPICAL THS4302 CHARACTERISTICS (3 V) 16 16 4000 14 14 3500 10 8 6 RL = 100 Ω VO = 100 mV VS = 3 V 4 12 10 8 6 RL = 100 Ω VO = 0.5 V VS = 3 V 4 2 0 1M 10 M 100 M 1G 10 G Rise 2000 1500 1000 RL = 100 Ω VS = 3 V 1M 10 M 100 M f − Frequency − Hz 1G 10 G 0 0.25 0.5 0.75 1 1.25 VO − Output Voltage − V Figure 34. Figure 35. Figure 36. OUTPUT VOLTAGE vs LOAD RESISTANCE CAPACITIVE LOAD FREQUENCY RESPONSE GAIN vs CASE TEMPERATURE Normalized Gain − dB 1.5 1.25 1 1000 Figure 37. 14 −0.5 R(ISO) = 8 Ω, CL = 100 pF −1 −1.5 13.94 RL = 100 Ω, VS = 5 V 10 M 13.98 13.96 R(ISO) = 12.1 Ω, CL = 47 pF −2 −3 0.75 VS = 3 V 14.02 0 −2.5 10 100 RL − Load Resistance − Ω R(ISO) = 24.9 Ω, CL = 10 pF 0.5 1.75 1.5 14.04 1 VS = 3 V TA = −40 to 85°C Gain − dB 2.25 1 Fall 2500 0 100 k f − Frequency − Hz 2 3000 500 0 100 k VO − Output Voltage − V SR − Slew Rate − V/ µ s 12 2 10 SLEW RATE vs OUTPUT VOLTAGE LARGE SIGNAL FREQUENCY RESPONSE Large Signal Gain − dB Small Signal Gain − dB SMALL SIGNAL FREQUENCY RESPONSE 100 M f − Frequency − Hz Figure 38. Submit Documentation Feedback 1G 13.92 −40−30−20−10 0 10 20 30 40 50 60 70 80 90 Case Temperature − °C Figure 39. Copyright © 2002–2006, Texas Instruments Incorporated Product Folder Link(s): THS4302 THS4302 www.ti.com SLOS403H – OCTOBER 2002 – REVISED AUGUST 2006 TYPICAL THS4302 CHARACTERISTICS (3 V) (continued) S-PARAMETER vs FREQUENCY RG C −20 −30 − + 50 Ω Source 3.5 S22 50 Ω 50 Ω VOS − Input Offset Voltage − mV S−Parameter − dB −10 50 Ω −40 −50 S11 −60 S12 −70 −80 −90 3 10 M 100 M 1G VS = 3 V 2.5 2 1.5 1 0.5 −100 1M 12 4 VS = 3 V RF 0 POSITIVE INPUT BIAS CURRENT vs CASE TEMPERATURE I IB+ − Positive Input Bias Current − µ A 10 INPUT OFFSET VOLTAGE vs CASE TEMPERATURE 0 −40−30−20−10 0 10 20 30 40 50 60 70 80 90 10 G f − Frequency − Hz 10 8 VS = 3 V 6 4 2 0 −40−30−20−10 0 10 20 30 40 50 60 70 80 90 Case Temperature − °C Case Temperature − °C Figure 41. Figure 42. Figure 40. OVERDRIVE RECOVERY 3 1.75 VO − Output Voltage − V 2.5 1.625 2.25 2 1.75 1.5 1.5 1.25 1 VI − Input Voltage − V 2.75 1.375 0.75 VS = 3 V 0.5 0.25 1.25 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 t − Time − µs Figure 43. Submit Documentation Feedback Copyright © 2002–2006, Texas Instruments Incorporated Product Folder Link(s): THS4302 11 THS4302 www.ti.com SLOS403H – OCTOBER 2002 – REVISED AUGUST 2006 APPLICATION INFORMATION High-Speed Operational amplifiers The THS4302 fixed-gain operational amplifier set new performance levels, combining low distortion, high slew rates, low noise, and a gain bandwidth in excess of 2 GHz. To achieve the full performance of the amplifier, careful attention must be paid to printed-circuit board layout and component selection. In addition, the devices provide a power-down mode with the ability to save power when the amplifier is inactive. Applications Section Contents • Wideband, Noninverting Operation • Single Supply Operation • Saving Power With Power-Down Functionality • Driving an ADC With the THS4302 • Driving Capacitive Loads • Power Supply Decoupling Techniques and Recommendations • Board Layout • Printed-Circuit Board Layout Techniques for Optimal Performance • PowerPAD Design Considerations • PowerPAD PCB Layout Considerations • Thermal Analysis • Design Tools • Evaluation Fixtures and Application Support Information • Additional Reference Material • Mechanical Package Drawings generator. The 50-Ω series resistor at the VO terminal in addition to the 50-Ω load impedance of the test equipment, provides a 100-Ω load. The total 100-Ω load at the output, combined with the 250-Ω total feedback network load, presents the THS4302 with an effective output load of 71 Ω for the circuit of Figure 44. INTERNAL FIXED RESISTOR VALUES DEVICE GAIN (V/V) Rf Rg THS4302 +5 200 50 VS+ + FB 22 µF 0.1 µF 47 pF 30.1 Ω Rf Rg 50-Ω Source _ + VI VO THS4302 49.9 Ω 100 Ω VS− + 22 µF FB 47 pF 0.1 µF 30.1 Ω FB = Ferrite Bead Figure 44. Wideband, Noninverting Gain Configuration WIDEBAND, NONINVERTING OPERATION SINGLE SUPPLY OPERATION The THS4302 is a fixed-gain voltage feedback operational amplifier, with power-down capability, designed to operate from a single 3-V to 5-V power supply. The THS4302 is designed to operate from a single 3-V to 5-V power supply. When operating from a single power supply, care must be taken to ensure the input signal and amplifier are biased appropriately to allow for the maximum output voltage swing. The circuits shown in Figure 45 demonstrate methods to configure an amplifier in a manner conducive for single supply operation. Figure 44 is the noninverting gain configuration used to demonstrate the typical performance curves. Most of the curves were characterized using signal sources with 50-Ω source impedance, and with measurement equipment presenting a 50-Ω load impedance. In Figure 44, the 49.9-Ω shunt resistor at the VIN terminal matches the source impedance of the test 12 Submit Documentation Feedback Copyright © 2002–2006, Texas Instruments Incorporated Product Folder Link(s): THS4302 THS4302 www.ti.com SLOS403H – OCTOBER 2002 – REVISED AUGUST 2006 APPLICATION CIRCUITS VS+ Driving an Analog-to-Digital Converter With the THS4302 + FB 22 µF 47 pF 0.1 µF 30.1 Ω Rf Rg 50-Ω Source *2.5 V VI _ + VO THS4302 100 Ω 49.9 Ω The THS4302 amplifier can be used to drive highperformance analog-to-digital converters. Two example circuits are presented below. The first circuit uses a wideband transformer to convert a single-ended input signal into a differential signal. The amplified signal from the output of the THS4302 is fed through a low-pass filter, via an isolation resistor and an ac-coupling capacitor, to the transformer. For applications without signal content at dc, this method of driving ADCs is useful. Where dc information content is required, the THS4500 family of fully differential amplifiers may be applicable. *2.5 V FB = Ferrite Bead * = Low Impedance Figure 45. DC-Coupled Single Supply Operation VS+ + Saving Power With Power-Down Functionality The power-down pin of the amplifier defaults to the positive supply voltage in the absence of an applied voltage, putting the amplifier in the power-on mode of operation. To turn off the amplifier in an effort to conserve power, the power-down pin can be driven towards the negative rail. The threshold voltages for power-on and power-down are relative to the supply rails and given in the specification tables. Above the Enable Threshold Voltage, the device is on. Below the Disable Threshold Voltage, the device is off. Behavior in between these threshold voltages is not specified. Note that this power-down functionality is just that; the amplifier consumes less power in power-down mode. The power-down mode is not intended to provide a high-impedance output. In other words, the power-down functionality is not intended to allow use as a 3-state bus driver. When in power-down mode, the impedance looking back into the output of the amplifier is dominated by the feedback and gain setting resistors, but the output impedance of the device itself varies depending on the voltage applied to the outputs. FB 22 µF The THS4302 features a power-down pin (PD) which lowers the quiescent current from 37 mA down to 800 μA, ideal for reducing system power. 0.1 µF 47 pF 30.1 Ω Rf Rg 50-Ω Source _ + *2.5 V VI THS4302 49.9 Ω *2.5 V RISO 0.1 µF 24.9 Ω IN 16.5 Ω FB = Ferrite Bead * = Low Impedance ADS5422 14-Bit, 63 Msps IN CM 24.9 Ω Figure 46. Driving an ADC Via a Transformer The second circuit depicts single-ended ADC drive. While not recommended for optimum performance using converters with differential inputs, satisfactory performance can sometimes be achieved with singleended input drive. An example circuit is shown here for reference. The time delays associated with turning the device on and off are specified as the time it takes for the amplifier to reach 50% of the nominal quiescent current. The time delays are on the order of microseconds because the amplifier moves in and out of the linear mode of operation in these transitions. Submit Documentation Feedback Copyright © 2002–2006, Texas Instruments Incorporated Product Folder Link(s): THS4302 13 THS4302 www.ti.com SLOS403H – OCTOBER 2002 – REVISED AUGUST 2006 VS+ + FB 22 µF 47 pF 0.1 µF 30.1 Ω Rf Rg 50-Ω Source _ + *2.5 V VI THS4302 The Typical Characteristics show the recommended isolation resistor vs capacitive load and the resulting frequency response at the load. Parasitic capacitive loads greater than 2 pF can begin to degrade the performance of the THS4302. Long PC board traces, unmatched cables, and connections to multiple devices can easily cause this value to be exceeded. Always consider this effect carefully, and add the recommended series resistor as close as possible to the THS4302 output pin (see Board Layout Guidelines). The criterion for setting this R(ISO) resistor is a maximum bandwidth, flat frequency response at the load. 49.9 Ω *2.5 V 1 RISO 0.1 µF 68 pf 16.5 Ω R(ISO) = 24.9 Ω, CL = 10 pF 0.5 IN ADS807 12-Bit, CM 53 Msps IN 1.82 kΩ 0.1 µF Normalized Gain - dB FB = Ferrite Bead * = Low Impedance For best performance, high-speed ADCs should be driven differentially. See the THS4500 family of devices for more information. 0 -0.5 -1 R(ISO) = 8 Ω, CL = 100 pF -1.5 -2 -2.5 R(ISO) = 12.1 Ω, CL = 47 pF VS = 5 V -3 10 M 100 M 1G f - Frequency - Hz Figure 47. Driving an ADC With a Single-Ended Input 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 A/D converter, including additional external capacitance, which may be recommended to improve A/D linearity. High-speed amplifiers like the THS4302 can be susceptible to decreased stability and closed-loop response peaking when a capacitive load is placed directly on the output pin. When the amplifier's open-loop output resistance is considered, this capacitive load introduces an additional pole in the signal path that can decrease the phase margin. When the primary considerations are frequency response flatness, pulse response fidelity, 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. 14 Figure 48. Driving Capacitive Loads Power Supply Decoupling Techniques and Recommendations Power supply decoupling is a critical aspect of any high-performance amplifier design process. Careful decoupling provides higher quality ac performance (most notably improved distortion performance). The following guidelines ensure the highest level of performance. 1. Place decoupling capacitors as close to the power supply inputs as possible, with the goal of minimizing the inductance of the path from ground to the power supply. Inductance in series with the bypass capacitors will degrade performance. Note that a narrow lead or trace has about 0.8 nH of inductance for every millimeter of length. Each printed-circuit board (PCB) via also has between 0.3 and 0.8 nH depending on length and diameter. For these reasons, it is recommended to use a power supply trace about the width of the package for each power supply lead to the capacitors, and 3 or more vias to connect the capacitors to the ground plane. 2. Placement priority should put the smallest valued capacitors closest to the device. 3. Solid power planes can lead to PCB resonances Submit Documentation Feedback Copyright © 2002–2006, Texas Instruments Incorporated Product Folder Link(s): THS4302 THS4302 www.ti.com SLOS403H – OCTOBER 2002 – REVISED AUGUST 2006 when they are not properly terminated to the ground plane over the area and along the perimeter of the power plane by high frequency capacitors. Doing so ensures that there are no power plane resonances in the needed frequency range. Values used are in the range of 2 pF - 50 pF, depending on the frequencies to be suppressed, with numerous vias for each. Using 0402 or smaller component sizes is recommended. An approximate expression for the resonant frequencies associated with a length of one of the power plane dimensions is given in the following equation. Note that a power plane of arbitrary shape can have a number of resonant frequencies. A power plane without distributed capacitors and with active parts near the center of the plane usually has n even (≥ 2) due to the half wave resonant nature of the plane. frequency res [ n (44 GHz mm) ȏ where: frequencyres = the approximate power plane resonant frequencies in GHz ȏ = the length of the power plane dimensions in millimeters n = an integer (n > 1) related to the mode of the oscillation For guidance on capacitor spacing over the area of the ground plane, specify the lowest resonant frequency to be tolerated, then solve using the equation above, with n = 2. Use this length for the capacitor spacing. It is recommended that a power plane, if used, be either small enough, or decoupled as described, so that there are no resonances in the frequency range of interest. An alternative is to use a ferrite bead outside the op-amp, high-frequency bypass capacitors to decouple the amplifier, and mid- and high-frequency bypass capacitors, from the power plane. When a trace is used to deliver power, its approximate self-resonance is given by the equation above, substituting the trace length for power plane dimension. 4. Bypass capacitors, because they have a self-inductance, resonate with each other. To achieve optimum transfer characteristics through 2 GHz, it is recommended that the bypass arrangement employed in the prototype board be used. The 30.1-Ω resistor in series with the 0.1-μF capacitor reduces the Q of the resonance of the lumped parallel elements including the 0.1-μF and 47-pF capacitors, and the power supply input of the amplifier. The ferrite bead isolates the low-frequency 22-μF capacitor and power plane from the remainder of the bypass network. 5. By removing the 30.1-Ω resistor and ferrite bead, the frequency response characteristic above 400 MHz may be modified. However, bandwidth, distortion, and transient response remain optimal. 6. Recommended values for power supply decoupling include a bulk decoupling capacitor (22 μF), a ferrite bead with a high self-resonant frequency, a mid-range decoupling capacitor (0.1 μF) in series with a 30.1-Ω resistor, and a high-frequency decoupling capacitor (47 pF). BOARD LAYOUT Printed-Circuit Board Layout Techniques for Optimal Performance Achieving optimum performance with a high frequency amplifier like the THS4302 requires careful attention to board layout parasitics and external component types. Recommendations that optimize performance include: 1. Minimize parasitic capacitance to any ac ground for all of the signal I/O pins. However, if using a transmission line at the I/O, then place the matching resistor as close to the part as possible. Except for when transmission lines are used, parasitic capacitance on the output and the noninverting input pins can react with the load and source impedances to cause unintentional band limiting. 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 planes and power planes (if used) should be unbroken elsewhere on the board, and terminated as described in the Power Supply Decoupling section. 2. Minimize the distance (< 0.25”) from the power supply pins to high frequency 0.1-μF 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. Note that each millimeter of a line, that is narrow relative to its length, has ~ 0.8 nH of inductance. The power supply connections should always be decoupled with the recommended capacitors. If not properly decoupled, distortion performance is degraded. Larger (6.8-μF to 22-μF) decoupling capacitors, effective at lower frequency, should also be used on the main supply lines, preferably decoupled from the amplifier and mid- and high-frequency capacitors by a ferrite bead. See the Power Supply Decoupling Techniques section. The larger caps may be placed somewhat farther from the device and may be shared among several devices in the same area of the PC board. A very low inductance path should be used to connect the inverting pin of the amplifier to ground. A minimum of 5 vias as close to the part as Submit Documentation Feedback Copyright © 2002–2006, Texas Instruments Incorporated Product Folder Link(s): THS4302 15 THS4302 www.ti.com SLOS403H – OCTOBER 2002 – REVISED AUGUST 2006 possible is recommended. 3. Careful selection and placement of external components preserves the high frequency performance of the THS4302. Resistors should be a low reactance type. Surface-mount resistors work best and allow a tighter overall layout. Axially-leaded parts do not provide good high frequency performance, because they have ~0.8 nH of inductance for every mm of current path length. Again, keep PC board trace length as short as possible. Never use wirewound type resistors in a high frequency application. Because the output pin and inverting input pin are the most sensitive to parasitic capacitance, always position the terminating resistors, if any, as close as possible to the noninverting and output 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 0.2 pF in shunt with the resistor. 4. 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 (50 mils to 100 mils) should be used, preferably with ground and power planes opened up around them. Estimate the total capacitive load and set RISO from the plot of recommended RISO vs Capacitive Load. Low parasitic capacitive loads (