CLC2605ISO8X

Data Sheet Comlinear CLC1605, CLC2605, CLC3605 ® 1.5GHz Amplifiers The COMLINEAR CLC1605 (single), CLC2605 (dual), and CLC3605 (triple) are high-performance, current feedback amplifiers that provide 1.5GHz unity gain bandwidth, ±0.1dB gain flatness to 120MHz, and 2,500V/μs slew rate. This high performance exceeds the requirements of high-definition television (HDTV) and other multimedia applications. These COMLINEAR highperformance amplifiers also provide ample output current to drive multiple video loads. The COMLINEAR CLC1605, CLC2605, and CLC3605 are designed to operate from ±5V or +5V supplies. The CLC3605 offers a fast enable/disable feature to save power. While disabled, the outputs are in a high-impedance state to allow for multiplexing applications. The combination of high-speed, lowpower, and excellent video performance make these amplifiers well suited for use in many general purpose, high-speed applications including highdefinition video, imaging applications, and radar/communications receivers. APPLICATIONS n RGB video line drivers n High definition video driver n Video switchers and routers n ADC buffer n Active filters n High-speed instrumentation n Wide dynamic range IF amp n Radar/communication receivers Typical Application - Driving Dual Video Loads +Vs 75Ω Cable Input 75Ω 75Ω Cable Output A 75Ω Rg 75Ω Rev 1E 75Ω Rf 75Ω Cable Output B 75Ω -Vs Ordering Information Part Number Package Pb-Free RoHS Compliant Operating Temperature Range Packaging Method CLC1605IST5X SOT23-5 Yes Yes -40°C to +85°C Reel CLC2605ISO8X* SOIC-8 Yes Yes -40°C to +85°C Reel CLC3605ISO16X SOIC-16 Yes Yes -40°C to +85°C Reel Moisture sensitivity level for all parts is MSL-1. *Preliminary. Exar Corporation 48720 Kato Road, Fremont CA 94538, USA Comlinear CLC1605, CLC2605, CLC3605 1.5GHz Amplifiers General Description FEATURES n 0.1dB gain flatness to 120MHz n 0.01%/0.01˚ differential gain/phase n 1.2GHz -3dB bandwidth at G = 2 n 700MHz large signal bandwidth n 2,500V/μs slew rate n 3.7nV/√Hz input voltage noise n 120mA output current n Triple offers disable n Fully specified at 5V and ±5V supplies n CLC1605: Pb-free SOT23-5 n CLC2605: Pb-free SOIC-8 n CLC3605: Pb-free SOIC-16 www.exar.com Tel. +1 510 668-7000 - Fax. +1 510 668-7001 Data Sheet CLC1605 Pin Configuration 1 -V S 2 +IN 3 +VS 5 + -IN 4 CLC2605 Pin Configuration OUT1 1 -IN1 2 +IN1 3 -Vs 4 + + 8 +Vs 7 OUT2 6 -IN2 5 +IN2 CLC3605 Pin Configuration Pin No. Pin Name 1 OUT Output 2 -VS Negative supply 3 +IN Positive input 4 -IN Negative input 5 +VS Positive supply CLC2605 Pin Assignments Pin No. Pin Name 1 OUT1 Output, channel 1 2 -IN1 Negative input, channel 1 3 +IN1 Positive input, channel 1 -VS 5 +IN2 DIS1 +IN1 2 15 OUT1 -VS 3 14 +VS -IN2 4 13 DIS2 +IN2 5 12 OUT2 -VS 6 11 +VS +IN3 7 10 OUT3 -IN3 8 9 DIS3 Negative supply Positive input, channel 2 6 -IN2 Negative input, channel 2 7 OUT2 Output, channel 2 8 +VS Positive supply CLC3605 Pin Configuration Pin Name Description 1 -IN1 Negative input, channel 1 2 +IN1 Positive input, channel 1 3 -VS Negative supply 4 -IN2 Negative input, channel 2 5 +IN2 Positive input, channel 2 6 -VS 7 +IN3 Positive input, channel 3 8 -IN3 Negative input, channel 3 9 DIS3 Disable pin. Enabled if pin is grounded, left floating or pulled below VON, disabled if pin is pulled above VOFF. 10 OUT3 Output, channel 3 Negative supply 11 +VS 12 OUT2 Positive supply Output, channel 2 13 DIS2 Disable pin. Enabled if pin is grounded, left floating or pulled below VON, disabled if pin is pulled above VOFF. 14 +VS Positive supply 15 OUT1 Output, channel 1 16 DIS1 Disable pin. Enabled if pin is grounded, left floating or pulled below VON, disabled if pin is pulled above VOFF. Disable Pin Truth Table Pin High Low* DIS Disabled Enabled *Default Open State ©2007-2013 Exar Corporation 2/21 Rev 1E Rev 1E -IN1 16 Description 4 Pin No. 1 Description Comlinear CLC1605, CLC2605, CLC3605 1.5GHz Amplifiers OUT CLC1605 Pin Assignments Data Sheet Absolute Maximum Ratings The safety of the device is not guaranteed when it is operated above the “Absolute Maximum Ratings”. The device should not be operated at these “absolute” limits. Adhere to the “Recommended Operating Conditions” for proper device function. The information contained in the Electrical Characteristics tables and Typical Performance plots reflect the operating conditions noted on the tables and plots. Supply Voltage Input Voltage Range Continuous Output Current Min Max Unit 0 -Vs -0.5V 14 +Vs +0.5V 120 V V mA Comlinear CLC1605, CLC2605, CLC3605 1.5GHz Amplifiers Parameter Reliability Information Parameter Min Junction Temperature Storage Temperature Range Lead Temperature (Soldering, 10s) Package Thermal Resistance 5-Lead SOT23 8-Lead SOIC 16-Lead SOIC Typ -65 Max Unit 150 150 260 °C °C °C 221 100 68 °C/W °C/W °C/W Notes: Package thermal resistance (qJA), JDEC standard, multi-layer test boards, still air. ESD Protection Product SOT23-5 SOIC-16 2kV 1kV 2kV 1kV Human Body Model (HBM) Charged Device Model (CDM) (1) Notes: 1. 0.8kV between the input pairs +IN and -IN pins only. All other pins are 2kV. Recommended Operating Conditions Min Operating Temperature Range Supply Voltage Range -40 4.5 ©2007-2013 Exar Corporation 3/21 Typ Max Unit +85 12 °C V Rev 1E Parameter Rev 1E Data Sheet Electrical Characteristics at +5V TA = 25°C, Vs = +5V, Rf = Rg =330Ω, RL = 150Ω to VS/2, G = 2; unless otherwise noted. Symbol Parameter Conditions Min Typ Max Units Frequency Domain Response Unity Gain Bandwidth G = +1, VOUT = 0.5Vpp, Rf = 499Ω 1250 MHz BWSS -3dB Bandwidth G = +2, VOUT = 0.5Vpp 1000 MHz BWLS Large Signal Bandwidth G = +2, VOUT = 1Vpp 825 MHz BW0.1dBSS 0.1dB Gain Flatness G = +2, VOUT = 0.5Vpp 100 MHz BW0.1dBLS 0.1dB Gain Flatness G = +2, VOUT = 1Vpp 100 MHz Time Domain Response tR, tF Rise and Fall Time VOUT = 1V step; (10% to 90%) 0.6 ns tS Settling Time to 0.1% VOUT = 1V step 10 ns OS Overshoot VOUT = 0.2V step 1 % SR Slew Rate 2V step 1350 V/µs Distortion/Noise Response HD2 2nd Harmonic Distortion VOUT = 1Vpp, 5MHz -75 dBc HD3 3rd Harmonic Distortion VOUT = 1Vpp, 5MHz -85 dBc THD Total Harmonic Distortion VOUT = 1Vpp, 5MHz 74 dB DG Differential Gain NTSC (3.58MHz), AC-coupled, RL = 150Ω 0.04 % DP Differential Phase NTSC (3.58MHz), AC-coupled, RL = 150Ω 0.01 ° IP3 Third Order Intercept VOUT = 1Vpp, 10MHz 37 dBm SFDR Spurious Free Dynamic Range VOUT = 1Vpp, 5MHz 61 dBc en Input Voltage Noise > 1MHz 3.7 nV/√Hz in Input Current Noise > 1MHz, Inverting 20 pA/√Hz > 1MHz, Non-Inverting 30 pA/√Hz XTALK Crosstalk Channel-to-channel 5MHz, VOUT = 2Vpp 60 dB DC Performance VIO Input Offset Voltage 0 mV dVIO Average Drift 1.6 µV/°C Ibn dIbn Ibi Average Drift Input Bias Current - Inverting Average Drift 3 µA 7 nA/°C 6 µA 20 nA/°C PSRR Power Supply Rejection Ratio DC 58 dB IS Supply Current per channel 11 mA ns Disable Characteristics - CLC3605 only TON Turn On Time 23 TOFF Turn Off Time 350 ns OFFIOS Off Isolation 5MHz, VOUT = 2Vpp 75 dB VOFF Power Down Input Voltage DIS pin, disabled if pin is pulled above VOFF Disabled if DIS > 1.5V V VON Enable Input Voltage DIS pin, enabled if pin is grounded, left open or pulled below VON Enabled if DIS < 0.5V V ISD Disable Supply Current DIS pin is pulled to VS 0.09 mA Non-inverting 150 kΩ Inverting 70 Ω 1.0 pF 1.5 to 3.5 V 50 dB Input Characteristics RIN Input Resistance CIN Input Capacitance CMIR Common Mode Input Range CMRR Common Mode Rejection Ratio DC ©2007-2013 Exar Corporation 4/21 Rev 1E Rev 1E dIbi Input Bias Current - Non-Inverting Comlinear CLC1605, CLC2605, CLC3605 1.5GHz Amplifiers UGBW Data Sheet Electrical Characteristics at +5V continued TA = 25°C, Vs = +5V, Rf = Rg =330Ω, RL = 150Ω to VS/2, G = 2; unless otherwise noted. Symbol Parameter Conditions Min Typ Max Units Output Characteristics Output Resistance Closed Loop, DC VOUT Output Voltage Swing RL = 150Ω IOUT Output Current 0.1 Ω 1.5 to 3.5 V ±120 mA Notes: 1. 100% tested at 25°C Comlinear CLC1605, CLC2605, CLC3605 1.5GHz Amplifiers RO Rev 1E ©2007-2013 Exar Corporation 5/21 Rev 1E Data Sheet Electrical Characteristics at ±5V TA = 25°C, Vs = ±5V, Rf = Rg =330Ω, RL = 150Ω to GND, G = 2; unless otherwise noted. Symbol Parameter Conditions Min Typ Max Units Frequency Domain Response Unity Gain Bandwidth G = +1, VOUT = 0.5Vpp, Rf = 499Ω 1500 MHz BWSS -3dB Bandwidth G = +2, VOUT = 0.5Vpp 1200 MHz BWLS Large Signal Bandwidth G = +2, VOUT = 2Vpp 700 MHz BW0.1dBSS 0.1dB Gain Flatness G = +2, VOUT = 0.5Vpp 120 MHz BW0.1dBLS 0.1dB Gain Flatness G = +2, VOUT = 2Vpp 120 MHz 0.65 ns ns Time Domain Response tR, tF Rise and Fall Time VOUT = 2V step; (10% to 90%) tS Settling Time to 0.1% VOUT = 2V step 13 OS Overshoot VOUT = 0.2V step 1 % SR Slew Rate 2V step 2500 V/µs Distortion/Noise Response HD2 2nd Harmonic Distortion VOUT = 2Vpp, 5MHz -73 dBc HD3 3rd Harmonic Distortion VOUT = 2Vpp, 5MHz -85 dBc THD Total Harmonic Distortion VOUT = 2Vpp, 5MHz 72 dB DG Differential Gain NTSC (3.58MHz), AC-coupled, RL = 150Ω 0.01 % DP Differential Phase NTSC (3.58MHz), AC-coupled, RL = 150Ω 0.01 ° IP3 Third Order Intercept VOUT = 2Vpp, 10MHz 42 dBm SFDR Spurious Free Dynamic Range VOUT = 1Vpp, 5MHz 73 dBc en Input Voltage Noise > 1MHz 3.7 nV/√Hz in Input Current Noise > 1MHz, Inverting 20 pA/√Hz > 1MHz, Non-Inverting 30 pA/√Hz XTALK Crosstalk Channel-to-channel 5MHz 60 dB DC Performance VIO dVIO Ibn dIbn Ibi -10 Average Drift 0 10 1.6 Input Bias Current - Non-Inverting (1) -40 Average Drift 19 40 7 Input Bias Current - Inverting (1) -35 Average Drift Power Supply Rejection Ratio (1) DC IS Supply Current (1) per channel 40 µA nA/°C 6 35 20 PSRR mV µV/°C µA nA/°C 60 dB 12 18 mA Disable Characteristics - CLC3605 only TON Turn On Time 35 TOFF Turn Off Time 410 ns ns OFFIOS Off Isolation 5MHz, VOUT = 2Vpp 75 dB VOFF Power Down Input Voltage DIS pin, disabled if pin is pulled above VOFF Disabled if DIS > 3V V VON Enable Input Voltage DIS pin, enabled if pin is grounded, left open or pulled below VON Enabled if DIS < 1V V ISD Disable Supply Current (1) per channel, DIS pin is pulled to VS 0.1 Non-inverting 150 Inverting 70 Ω 1.0 pF 0.3 mA Input Characteristics RIN Input Resistance CIN Input Capacitance CMIR Common Mode Input Range CMRR Common Mode Rejection Ratio (1) DC ©2007-2013 Exar Corporation 40 6/21 kΩ ±4.0 V 55 dB Rev 1E Rev 1E dIbi Input Offset Voltage (1) Comlinear CLC1605, CLC2605, CLC3605 1.5GHz Amplifiers UGBW Data Sheet Electrical Characteristics at ±5V continued TA = 25°C, Vs = ±5V, Rf = Rg =330Ω, RL = 150Ω to GND, G = 2; unless otherwise noted. Symbol Parameter Conditions Min Typ Max Units Output Characteristics Output Resistance Closed Loop, DC VOUT Output Voltage Swing RL = 150Ω IOUT Output Current 0.1 ±3.0 (1) Ω ±3.8 V ±280 mA Notes: 1. 100% tested at 25°C Comlinear CLC1605, CLC2605, CLC3605 1.5GHz Amplifiers RO Rev 1E ©2007-2013 Exar Corporation 7/21 Rev 1E Data Sheet Typical Performance Characteristics TA = 25°C, Vs = ±5V, Rf = Rg =330Ω, RL = 150Ω to GND, G = 2; unless otherwise noted. Non-Inverting Frequency Response Normalized Gain (dB) G=2 G=5 G = 10 -6 G = -2 -1 0 -3 G = -1 0 G=1 Rf = 750Ω G = -5 -2 -3 G = -10 -4 -5 -6 VOUT = 0.5Vpp -9 VOUT = 0.5Vpp -7 0.1 1 10 100 1000 0.1 1 Frequency (MHz) Frequency Response vs. CL 1000 5 4 0 3 CL = 1000pF Rs = 3.3Ω -1 Normalized Gain (dB) Normalized Gain (dB) 100 Frequency Response vs. RL 1 CL = 500pF Rs = 5Ω -2 -3 CL = 100pF Rs = 10Ω -4 CL = 50pF Rs = 15Ω -5 -6 CL = 20pF Rs = 20Ω VOUT = 0.5Vpp 2 1 0 -1 RL = 100Ω -2 -3 RL = 50Ω -4 VOUT = 0.5Vpp -5 -7 RL = 25Ω -6 0.1 1 10 100 1000 0.1 1 Frequency (MHz) 10 100 1000 Frequency (MHz) Rev 1E Frequency Response vs. VOUT Frequency Response vs. Temperature 1 2 0 1 0 -1 Normalized Gain (dB) Normalized Gain (dB) 10 Frequency (MHz) VOUT = 4Vpp -2 -3 VOUT = 2Vpp -4 VOUT = 1Vpp -5 -1 + 25degC -2 - 40degC -3 + 85degC -4 -5 -6 VOUT = 0.2Vpp -6 -7 -7 0.1 1 10 100 1000 0.1 Frequency (MHz) ©2007-2013 Exar Corporation 1 10 100 1000 10000 Frequency (MHz) 8/21 Comlinear CLC1605, CLC2605, CLC3605 1.5GHz Amplifiers 1 G=1 Rf = 499Ω 3 Normalized Gain (dB) Inverting Frequency Response Rev 1E Data Sheet Typical Performance Characteristics TA = 25°C, Vs = ±5V, Rf = Rg =330Ω, RL = 150Ω to GND, G = 2; unless otherwise noted. Non-Inverting Frequency Response at VS = 5V Normalized Gain (dB) G=2 G=5 G = 10 -6 G = -2 -1 0 -3 G = -1 0 G=1 Rf = 750Ω G = -5 -2 -3 G = -10 -4 -5 -6 VOUT = 0.5Vpp -9 VOUT = 0.5Vpp -7 0.1 1 10 100 1000 0.1 1 Frequency (MHz) Frequency Response vs. CL at VS = 5V 1000 3 2 0 CL = 1000pF Rs = 3.3Ω -1 1 Normalized Gain (dB) Normalized Gain (dB) 100 Frequency Response vs. RL at VS = 5V 1 CL = 500pF Rs = 5Ω -2 -3 CL = 100pF Rs = 10Ω -4 CL = 50pF Rs = 15Ω -5 -6 VOUT = 0.5Vpp 0 -1 RL = 100Ω -2 RL = 50Ω -3 -4 CL = 20pF Rs = 20Ω RL = 25Ω VOUT = 0.5Vpp -5 -7 -6 0.1 1 10 100 1000 0.1 1 Frequency (MHz) 10 100 1000 Frequency (MHz) Rev 1E Frequency Response vs. VOUT at VS = 5V Frequency Response vs. Temperature at VS = 5V 1 2 0 1 0 -1 VOUT = 3Vpp Normalized Gain (dB) Normalized Gain (dB) 10 Frequency (MHz) -2 -3 VOUT = 2Vpp -4 VOUT = 1Vpp -5 -1 -2 + 25degC -3 - 40degC -4 + 85degC -5 -6 VOUT = 0.2Vpp -6 -7 -7 0.1 1 10 100 1000 0.1 Frequency (MHz) ©2007-2013 Exar Corporation 1 10 100 1000 10000 Frequency (MHz) 9/21 Comlinear CLC1605, CLC2605, CLC3605 1.5GHz Amplifiers 1 G=1 Rf = 499Ω 3 Normalized Gain (dB) Inverting Frequency Response at VS = 5V Rev 1E Data Sheet Typical Performance Characteristics - Continued TA = 25°C, Vs = ±5V, Rf = Rg =330Ω, RL = 150Ω to GND, G = 2; unless otherwise noted. Gain Flatness at VS = 5V 0.1 0 0 Normalized Gain (dB) 0.1 -0.1 -0.2 -0.3 VOUT = 2Vpp RL = 150Ω Rf = 330Ω -0.4 -0.1 -0.2 -0.3 VOUT = 2Vpp RL = 150Ω Rf = 330Ω -0.4 -0.5 -0.5 0.1 1 10 100 1000 0.1 1 Frequency (MHz) -3dB Bandwidth vs. VOUT 1000 1200 1100 1600 1000 1400 -3dB Bandwidth (MHz) -3dB Bandwidth (MHz) 100 -3dB Bandwidth vs. VOUT at VS = 5V 1800 1200 1000 800 600 900 800 700 600 500 400 400 300 200 200 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 0.0 0.5 VOUT (VPP) 1.0 1.5 2.0 2.5 3.0 VOUT (VPP) Rev 1E Closed Loop Output Impedance vs. Frequency Input Voltage Noise 10 25 Input Voltage Noise (nV/√Hz) VS = ±5.0V Output Resistance (Ω) 10 Frequency (MHz) 1 0.1 0.01 10K 100K 1M 10M 15 10 5 0.001 0.01 0.1 1 10 Frequency (MHz) Frequency (Hz) ©2007-2013 Exar Corporation 20 0 0.0001 100M 10/21 Comlinear CLC1605, CLC2605, CLC3605 1.5GHz Amplifiers Normalized Gain (dB) Gain Flatness Rev 1E Data Sheet Typical Performance Characteristics - Continued TA = 25°C, Vs = ±5V, Rf = Rg =330Ω, RL = 150Ω to GND, G = 2; unless otherwise noted. 2nd Harmonic Distortion vs. RL 3rd Harmonic Distortion vs. RL -65 -60 -70 RL = 150Ω -75 -70 Distortion (dBc) Distortion (dBc) -65 -75 -80 -85 RL = 150Ω -80 -85 -90 -90 RL = 1kΩ -95 -95 VOUT = 2Vpp -100 RL = 1kΩ VOUT = 2Vpp -100 0 5 10 15 20 0 5 Frequency (MHz) 10 2nd Harmonic Distortion vs. VOUT 20 3rd Harmonic Distortion vs. VOUT -60 -70 -65 10MHz -75 10MHz Distortion (dBc) -70 Distortion (dBc) 15 Frequency (MHz) -75 -80 5MHz -85 -90 1MHz RL = 150Ω 0.5 0.75 -80 5MHz -85 -90 1MHz -95 -95 -100 RL = 150Ω 100Ω -100 1 1.25 1.5 1.75 2 2.25 2.5 0.5 0.75 1 Output Amplitude (Vpp) 1.25 1.5 1.75 2 2.25 2.5 Output Amplitude (Vpp) Rev 1E CMRR vs. Frequency PSRR vs. Frequency -25 0 -30 -10 -35 -20 PSRR (dB) CMRR (dB) VS = ±5.0V -40 -45 -50 -30 -40 -50 -55 -60 10k 100k Comlinear CLC1605, CLC2605, CLC3605 1.5GHz Amplifiers -55 1M 10M 10K 100M ©2007-2013 Exar Corporation 100K 1M 10M 100M Frequency (Hz) Frequency (Hz) 11/21 Rev 1E Data Sheet Typical Performance Characteristics - Continued TA = 25°C, Vs = ±5V, Rf = Rg =330Ω, RL = 150Ω to GND, G = 2; unless otherwise noted. Small Signal Pulse Response at VS = 5V 0.125 2.625 0.1 2.6 0.075 2.575 2.55 0.025 2.525 Voltage (V) 0.05 0 -0.025 2.5 2.475 -0.05 2.45 -0.075 2.425 -0.1 2.4 -0.125 2.375 0 20 40 60 80 100 120 140 160 180 200 0 20 40 60 80 Time (ns) 100 120 140 160 180 200 Time (ns) Large Signal Pulse Response Large Signal Pulse Response at VS = 5V 2.5 4 2 3.5 1.5 3 0.5 Voltage (V) Voltage (V) 1 0 -0.5 2.5 2 -1 -1.5 1.5 -2 -2.5 1 0 20 40 60 80 100 120 140 160 180 200 0 20 40 60 Time (ns) 100 120 140 160 180 200 Time (ns) Differential Gain & Phase DC Coupled Output 0.01 0.03 Diff Gain (%) / Diff Phase (°) 0.005 DG 0 -0.005 DP -0.01 -0.015 RL = 150Ω AC coupled -0.02 0.02 DP DG 0.01 0 -0.01 -0.02 RL = 150Ω DC coupled -0.03 -0.7 -0.5 -0.3 -0.1 0.1 0.3 0.5 0.7 -0.7 Input Voltage (V) ©2007-2013 Exar Corporation -0.5 -0.3 -0.1 0.1 0.3 0.5 0.7 Input Voltage (V) 12/21 Rev 1E Rev 1E Differential Gain & Phase AC Coupled Output Diff Gain (%) / Diff Phase (°) 80 Comlinear CLC1605, CLC2605, CLC3605 1.5GHz Amplifiers Voltage (V) Small Signal Pulse Response Data Sheet Typical Performance Characteristics - Continued TA = 25°C, Vs = ±5V, Rf = Rg =330Ω, RL = 150Ω to GND, G = 2; unless otherwise noted. Differential Gain & Phase AC Coupled Output at VS = ±2.5V Differential Gain & Phase DC Coupled at VS = ±2.5V 0.01 0 Diff Gain (%) / Diff Phase (°) Diff Gain (%) / Diff Phase (°) DP -0.01 -0.02 DG -0.03 -0.04 RL = 150Ω AC coupled -0.01 -0.02 DG -0.03 -0.04 -0.05 -0.06 RL = 150Ω DC coupled -0.07 -0.05 -0.35 DP 0 -0.25 -0.15 -0.05 0.05 0.15 0.25 -0.35 0.35 -0.25 -0.15 0.05 0.15 0.25 0.35 Crosstalk vs. Frequency at VS=5V (CLC3605) -30 -30 -35 -35 -40 -40 -45 -45 -50 -50 Crosstalk (dB) Crosstalk (dB) Crosstalk vs. Frequency (CLC3605) -55 -60 -65 -70 -55 -60 -65 -70 -75 -75 -80 -80 -85 -85 VOUT = 2Vpp -90 VOUT = 1Vpp -90 -95 -95 0.1 1 10 100 0.1 1 Frequency (MHz) 10 100 Frequency (MHz) Off Isolation vs. Frequency at VS=5V -45 -50 -50 -55 -55 -60 -60 -65 -65 Off Isolation (dB) -45 -70 -75 -80 -85 -90 -70 -75 -80 -85 -90 -95 -95 -100 -100 VOUT = 2Vpp -105 Rev 1E Off Isolation vs. Frequency Off Isolation (dB) -0.05 Input Voltage (V) Input Voltage (V) VOUT = 1Vpp -105 -110 -110 0.1 1 10 100 0.1 Frequency (MHz) ©2007-2013 Exar Corporation 1 10 100 Frequency (MHz) 13/21 Comlinear CLC1605, CLC2605, CLC3605 1.5GHz Amplifiers 0.02 0.01 Rev 1E Data Sheet General Information - Current Feedback Technology Advantages of CFB Technology CFB also alleviates the traditional trade-off between closed loop gain and usable bandwidth that is seen with a VFB amplifier. With CFB, the bandwidth is primarily determined by the value of the feedback resistor, Rf. By using optimum feedback resistor values, the bandwidth of a CFB amplifier remains nearly constant with different gain configurations. When designing with CFB amplifiers always abide by these basic rules: • Use the recommended feedback resistor value • Do not use reactive (capacitors, diodes, inductors, etc.) elements in the direct feedback path • Avoid stray or parasitic capacitance across feedback resistors • Follow general high-speed amplifier layout guidelines • Ensure proper precautions have been made for driving capacitive loads Ierr x1 Zo*Ierr VOUT Rf RL Rg VOUT VIN = 1+ Rf Rg + 1+ 1 Rf Eq. 1 Zo(jω) Figure 1. Non-Inverting Gain Configuration with First Order Transfer Function ©2007-2013 Exar Corporation VIN Rg VOUT VIN VOUT Rf = − Rf Rg + 1+ 1 Rf RL Eq. 2 Zo(jω) Figure 2. Inverting Gain Configuration with First Order Transfer Function CFB Technology - Theory of Operation Figure 1 shows a simple representation of a current feedback amplifier that is configured in the traditional non-inverting gain configuration. Instead of having two high-impedance inputs similar to a VFB amplifier, the inputs of a CFB amplifier are connected across a unity gain buffer. This buffer has a high impedance input and a low impedance output. It can source or sink current (Ierr) as needed to force the non-inverting input to track the value of Vin. The CFB architecture employs a high gain trans-impedance stage that senses Ierr and drives the output to a value of (Zo(jω) * Ierr) volts. With the application of negative feedback, the amplifier will drive the output to a voltage in a manner which tries to drive Ierr to zero. In practice, primarily due to limitations on the value of Zo(jω), Ierr remains a small but finite value. A closer look at the closed loop transfer function (Eq.1) shows the effect of the trans-impedance, Zo(jω) on the gain of the circuit. At low frequencies where Zo(jω) is very large with respect to Rf, the second term of the equation approaches unity, allowing Rf and Rg to set the gain. At higher frequencies, the value of Zo(jω) will roll off, and the effect of the secondary term will begin to dominate. The -3dB small signal parameter specifies the frequency where the value Zo(jω) equals the value of Rf causing the gain to drop by 0.707 of the value at DC. For more information regarding current feedback amplifiers, visit www.exar.com for detailed application notes, such as AN-3: The Ins and Outs of Current Feedback Amplifiers. 14/21 Rev 1E Rev 1E VIN Ierr Zo*Ierr Comlinear CLC1605, CLC2605, CLC3605 1.5GHz Amplifiers The CLC1605 Family of amplifiers utilize current feedback (CFB) technology to achieve superior performance. The primary advantage of CFB technology is higher slew rate performance when compared to voltage feedback (VFB) architecture. High slew rate contributes directly to better large signal pulse response, full power bandwidth, and distortion. x1 Data Sheet Application Information Basic Operation +Vs Input Feedback Resistor Selection 6.8μF 0.1μF + Output - RL 0.1μF Rg Rf 6.8μF G = 1 + (Rf/Rg) -Vs Figure 3. Typical Non-Inverting Gain Circuit +Vs R1 Input 0.1μF + Rg 6.8μF One of the key design considerations when using a CFB amplifier is the selection of the feedback resistor, Rf. Rf is used in conjunction with Rg to set the gain in the traditional non-inverting and inverting circuit configurations. Refer to figures 3 and 4. As discussed in the Current Feedback Technology section, the value of the feedback resistor has a pronounced effect on the frequency response of the circuit. Table 1, provides recommended Rf and associated Rg values for various gain settings. These values produce the optimum frequency response, maximum bandwidth with minimum peaking. Adjust these values to optimize performance for a specific application. The typical performance characteristics section includes plots that illustrate how the bandwidth is directly affected by the value of Rf at various gain settings. Output - RL 0.1μF Rf 6.8μF For optimum input offset voltage set R1 = Rf || Rg Figure 4. Typical Inverting Gain Circuit +Vs Input 6.8μF 0.1μF + Output 0.1μF 6.8μF -Vs RL Rf G=1 Rf is required for CFB amplifiers Rf (Ω) Rg (Ω) ±0.1dB BW (MHz) -3dB BW (MHz) 1 499 - 167 1500 2 330 330 120 1200 5 330 82.5 66 385 10 330 33 38 245 Rev 1E G = - (Rf/Rg) -Vs Gain (V/V Table 1: Recommended Rf vs. Gain In general, lowering the value of Rf from the recommended value will extend the bandwidth at the expense of additional high frequency gain peaking. This will cause increased overshoot and ringing in the pulse response characteristics. Reducing Rf too much will eventually cause oscillatory behavior. Increasing the value of Rf will lower the bandwidth. Lowering the bandwidth creates a flatter frequency response and improves 0.1dB bandwidth performance. This is important in applications such as video. Further increase in Rf will cause premature gain rolloff and adversely affect gain flatness. Figure 5. Typical Unity Gain (G=1) Circuit ©2007-2013 Exar Corporation 15/21 Comlinear CLC1605, CLC2605, CLC3605 1.5GHz Amplifiers Figures 3, 4, and 5 illustrate typical circuit configurations for non-inverting, inverting, and unity gain topologies for dual supply applications. They show the recommended bypass capacitor values and overall closed loop gain equations. CFB amplifiers can be used in unity gain configurations. Do not use the traditional voltage follower circuit, where the output is tied directly to the inverting input. With a CFB amplifier, a feedback resistor of appropriate value must be used to prevent unstable behavior. Refer to figure 5 and Table 1. Although this seems cumbersome, it does allow a degree of freedom to adjust the passband characteristics. Rev 1E Data Sheet Driving Capacitive Loads In general, avoid adding any additional parasitic capacitance at this node. In addition, stray capacitance across the Rf resistor can induce peaking and high frequency ringing. Refer to the Layout Considerations section for additional information regarding high speed layout techniques. Overdrive Recovery + Rs - Output CL Rf RL Rg Figure 6. Addition of RS for Driving Capacitive Loads Table 2 provides the recommended RS for various capacitive loads. The recommended RS values result in