CLC1603

Data Sheet A m p l i fy t h e H u m a n E x p e r i e n c e ® Comlinear CLC1603, CLC3603, CLC3613 features n 0.1dB gain flatness to 30MHz n 0.01%/0.03˚ differential gain/phase n 200MHz -3dB bandwidth at G = 2 n 140MHz large signal bandwidth n 450V/μs slew rate n 1.1mA supply current (enabled) n 0.35mA supply current (disabled) n 100mA output current n Fully specified at 5V and ±5V supplies n CLC1603: Pb-free SOT23-6 n CLC3603: Pb-free SOIC-16 n CLC3613: Pb-free SOIC-14 applications n RGB video line drivers n Portable Video n Line drivers n Set top box n Active filters n Cable drivers n Imaging applications n Radar/communication receivers Single and Triple, 1.1mA, 200MHz Amplifiers Comlinear CLC1603, CLC3603, CLC3613 Single and Triple, 1.1mA, 200MHz Amplifiers General Description The COMLINEAR CLC1603 (single with disable), CLC3603 (triple with disable), and CLC3613 (triple) are high-performance, current feedback amplifiers that provide 240MHz unity gain bandwidth, ±0.1dB gain flatness to 30MHz, and 450V/μs slew rate while consuming only 1.1mA of supply current. This high performance exceeds the requirements of NTSC/PAL/HDTV video applications. These COMLINEAR high-performance amplifiers also provide ample output current to drive multiple video loads. The COMLINEAR CLC1603, CLC3603, and CLC3613 are designed to operate from ±5V or +5V supplies. The CLC1603 and CLC3603 offer a 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, low-power, and excellent video performance make these amplifiers well suited for use in many general purpose, high-speed applications including set top boxes, high-definition video, active filters, and cable driving applications. Typical Application - Driving Dual Video Loads Ordering Information Part Number CLC1603IST6X CLC3613ISO14X CLC3613ISO14 CLC3603ISO16X CLC3603ISO16 Package SOT23-6 SOIC-14 SOIC-14 SOIC-16 SOIC-16 Disable Option Yes No No Yes Yes Pb-Free Yes Yes Yes Yes Yes RoHS Compliant Yes Yes Yes Yes Yes Operating Temperature Range -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C Packaging Method Reel Reel Rail Reel Rail Rev 1A Moisture sensitivity level for all parts is MSL-1. ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com Data Sheet CLC1603 Pin Configuration CLC1603 Pin Assignments Pin No. Pin Name OUT -VS +IN -IN DIS +VS Description Output Negative supply Positive input Negative input Disable. Enabled if pin is left floating or pulled above VON, disabled if pin is grounded or pulled below VOFF. Positive supply 1 2 3 4 5 6 OUT -V S +IN 1 2 3 + 6 +VS DIS -IN - 5 4 Comlinear CLC1603, CLC3603, CLC3613 Single and Triple, 1.1mA, 200MHz Amplifiers CLC3603 Pin Configuration -IN1 +IN1 -VS -IN2 +IN2 -VS +IN3 -IN3 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 CLC3603 Pin Assignments Pin No. Pin Name -IN1 +IN1 -VS -IN2 +IN2 -VS +IN3 -IN3 DIS3 OUT3 +VS OUT2 DIS2 +VS OUT1 DIS1 Description Negative input, channel 1 Positive input, channel 1 Negative supply Negative input, channel 2 Positive input, channel 2 Negative supply Positive input, channel 3 Negative input, channel 3 Disable pin for channel 3. Enabled if pin is left floating or pulled above VON, disabled if pin is grounded or pulled below VOFF. Output, channel 3 Positive supply Output, channel 2 Disable pin for channel 2. Enabled if pin is left floating or pulled above VON, disabled if pin is grounded or pulled below VOFF. Positive supply Output, channel 1 Disable pin for channel 2. Enabled if pin is left floating or pulled above VON, disabled if pin is grounded or pulled below VOFF. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 DIS1 OUT1 +VS DIS2 OUT2 +VS OUT3 DIS3 Disable Pin Truth Table Pin DIS *Default Open State High* ( > (+Vs - 1.5V)) Enabled Low ( < (+Vs - 3.5V)) Disabled Rev 1A ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 2 Data Sheet CLC3613 Pin Configuration CLC3613 Pin Assignments Pin No. Pin Name NC NC NC +VS +IN1 -IN1 OUT1 OUT3 -IN3 +IN3 -VS +IN2 -IN2 OUT2 Description No Connect No Connect No Connect Positive supply Positive input, channel 1 Negative input, channel 1 Output, channel 1 Output, channel 3 Negative input, channel 3 Positive input, channel 3 Negative supply Positive input, channel 2 Negative input, channel 2 Output, channel 2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 NC NC NC +VS +IN1 -IN1 OUT1 1 2 3 4 5 6 7 14 13 12 11 10 9 8 OUT2 -IN2 +IN2 -VS +IN3 -IN3 OUT3 Comlinear CLC1603, CLC3603, CLC3613 Single and Triple, 1.1mA, 200MHz Amplifiers Rev 1A ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 3 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. Comlinear CLC1603, CLC3603, CLC3613 Single and Triple, 1.1mA, 200MHz Amplifiers Parameter Supply Voltage Input Voltage Range Continuous Output Current Min 0 -Vs -0.5V Max 14 +Vs +0.5V 100 Unit V V mA Reliability Information Parameter Junction Temperature Storage Temperature Range Lead Temperature (Soldering, 10s) Package Thermal Resistance 6-Lead SOT23 14-Lead SOIC 16-Lead SOIC Notes: Package thermal resistance (qJA), JDEC standard, multi-layer test boards, still air. Min -65 Typ Max 150 150 300 Unit °C °C °C °C/W °C/W °C/W 177 88 68 ESD Protection Product Human Body Model (HBM) Charged Device Model (CDM) SOT23-6 2kV 1kV SOIC-14 2kV 1kV SOIC-16 2kV 1kV Recommended Operating Conditions Parameter Operating Temperature Range Supply Voltage Range Min -40 4.5 Typ Max +85 12 Unit °C V Rev 1A ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 4 Data Sheet Electrical Characteristics at +5V TA = 25°C, +Vs = 5V, -VS = GND, Rf = Rg =1.2kΩ, RL = 100Ω to +VS/2, G = 2; unless otherwise noted. symbol UGBW BWSS BWLS BW0.1dBSS tR, tF tS OS SR HD2 HD3 THD DG DP IP3 SFDR en in XTALK VIO dVIO Ibn dIbn Ibi dIbi PSRR IS TON TOFF VOFF VON ISD parameter Unity Gain Bandwidth -3dB Bandwidth Large Signal Bandwidth 0.1dB Gain Flatness Rise and Fall Time Settling Time to 0.1% Settling Time to 0.01% Overshoot Slew Rate 2nd Harmonic Distortion 3rd Harmonic Distortion Total Harmonic Distortion Differential Gain Differential Phase Third Order Intercept Spurious Free Dynamic Range Input Voltage Noise Input Current Noise Crosstalk Input Offset Voltage Average Drift Input Bias Current - Non-Inverting Average Drift Input Bias Current - Inverting Average Drift Power Supply Rejection Ratio Supply Current Turn On Time Turn Off Time Power Down Input Voltage Enable Input Voltage Disable Supply Current conditions G = +1, VOUT = 0.5Vpp, Rf = 2.5kΩ G = +2, VOUT = 0.5Vpp G = +2, VOUT = 1Vpp G = +2, VOUT = 0.5Vpp VOUT = 1V step; (10% to 90%) VOUT = 1V step VOUT = 1V step VOUT = 0.2V step 1V step VOUT = 1Vpp, 5MHz VOUT = 1Vpp, 5MHz VOUT = 1Vpp, 5MHz NTSC (3.58MHz), AC-coupled, RL = 150Ω NTSC (3.58MHz), AC-coupled, RL = 150Ω VOUT = 1Vpp, 10MHz VOUT = 1Vpp, 5MHz > 1MHz > 1MHz, Inverting > 1MHz, Non-Inverting Channel-to-channel 5MHz Min typ 210 180 160 15 3 18 40 1 350 -60 -51 50 0.01 0.04 26 58 4 15 15 56 0.5 6 2 40 0.4 10 Max units MHz MHz MHz MHz ns ns ns % V/µs dBc dBc dB % ° dBm dBc nV/√Hz pA/√Hz pA/√Hz dB mV µV/°C µA nA/°C µA nA/°C dB mA ns μs V V mA MΩ Ω pF V dB Frequency Domain Response Comlinear CLC1603, CLC3603, CLC3613 Single and Triple, 1.1mA, 200MHz Amplifiers Time Domain Response Distortion/Noise Response DC Performance DC per channel 60 0.9 100 2.25 Disable Characteristics - CLC1603, CLC3603 DIS pin, disabled if pin is grounded or pulled below VOFF = +Vs - 3.5V DIS pin, enabled if pin is left open or pulled above VON = +Vs - 1.5V DIS pin is grounded Non-inverting Inverting Disabled if < (+Vs - 3.5V) Enabled if > (+Vs - 1.5V) 0.15 4 350 1.0 1.5 to 3.5 Input Characteristics RIN CIN CMIR CMRR Input Resistance Input Capacitance Common Mode Input Range Common Mode Rejection Ratio DC Rev 1A 55 ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 5 Data Sheet Electrical Characteristics at +5V continued TA = 25°C, +Vs = 5V, -VS = GND, Rf = Rg =1.2kΩ, RL = 100Ω to +VS/2, G = 2; unless otherwise noted. symbol RO VOUT IOUT parameter Output Resistance Output Voltage Swing Output Current conditions Closed Loop, DC RL = 100Ω Min typ 0.02 1.4 to 3.6 ±140 Max units Ω V mA Output Characteristics Comlinear CLC1603, CLC3603, CLC3613 Single and Triple, 1.1mA, 200MHz Amplifiers Rev 1A ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 6 Data Sheet Electrical Characteristics at ±5V TA = 25°C, +Vs = 5V, -VS = -5V, Rf = Rg =1.2kΩ, RL = 100Ω to GND, G = 2; unless otherwise noted. symbol UGBW BWSS BWLS BW0.1dBSS tR, tF tS OS SR HD2 HD3 THD DG DP IP3 SFDR en in XTALK VIO dVIO Ibn dIbn Ibi dIbi PSRR IS parameter Unity Gain Bandwidth -3dB Bandwidth Large Signal Bandwidth 0.1dB Gain Flatness Rise and Fall Time Settling Time to 0.1% Settling Time to 0.01% Overshoot Slew Rate 2nd Harmonic Distortion 3rd Harmonic Distortion Total Harmonic Distortion Differential Gain Differential Phase Third Order Intercept Spurious Free Dynamic Range Input Voltage Noise Input Current Noise Crosstalk Input Offset Voltage (1) Average Drift Input Bias Current - Non-Inverting (1) Average Drift Input Bias Current - Inverting (1) Average Drift Power Supply Rejection Ratio (1) Supply Current (1) conditions G = +1, VOUT = 0.5Vpp, Rf = 2.5kΩ G = +2, VOUT = 0.5Vpp G = +2, VOUT = 2Vpp G = +2, VOUT = 0.5Vpp VOUT = 2V step; (10% to 90%) VOUT = 2V step VOUT = 2V step VOUT = 0.2V step 2V step VOUT = 2Vpp, 5MHz VOUT = 2Vpp, 5MHz VOUT = 2Vpp, 5MHz, RL = 150Ω NTSC (3.58MHz), AC-coupled, RL = 150Ω NTSC (3.58MHz), AC-coupled, RL = 150Ω VOUT = 0.5Vpp, 10MHz VOUT = 1Vpp, 5MHz > 1MHz > 1MHz, Inverting > 1MHz, Non-Inverting Channel-to-channel 5MHz Min typ 240 200 120 30 4 18 35 1 450 -67 -57 55 0.01 0.03 35 58 4 15 15 56 Max units MHz MHz MHz MHz ns ns ns % V/µs dBc dBc dB % ° dBm dBc nV/√Hz pA/√Hz pA/√Hz dB Frequency Domain Response Comlinear CLC1603, CLC3603, CLC3613 Single and Triple, 1.1mA, 200MHz Amplifiers Time Domain Response Distortion/Noise Response DC Performance -4 -5 -5 DC CLC1603 CLC3603, CLC3613 50 0.7 6 2 40 2 10 75 1.1 3.3 250 2.25 DIS pin, disabled if pin is grounded or pulled below VOFF = +Vs - 3.5V DIS pin, enabled if pin is left open or pulled above VON = +Vs - 1.5V DIS pin is grounded, CLC1603 DIS pin is grounded, CLC3603 Non-inverting Inverting Disabled if < (+Vs - 3.5V) Enabled if > (+Vs - 1.5V) 0.11 0.3 4 350 1.0 ±4.0 0.5 0.5 2.5 6.5 5 5 4 mV µV/°C µA nA/°C µA nA/°C dB mA mA ns μs V V mA mA MΩ Ω pF V Disable Characteristics - CLC1603, CLC3603 TON TOFF VOFF VON ISD Turn On Time Turn Off Time Power Down Input Voltage Enable Input Voltage Disable Supply Current (1) Input Characteristics RIN CIN CMIR Input Resistance Input Capacitance Common Mode Input Range Rev 1A ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 7 Data Sheet Electrical Characteristics at ±5V continued TA = 25°C, +Vs = 5V, -VS = -5V, Rf = Rg =1.2kΩ, RL = 100Ω to GND, G = 2; unless otherwise noted. symbol CMRR RO VOUT IOUT notes: 1. 100% tested at 25°C parameter Common Mode Rejection Ratio Output Resistance Output Voltage Swing Output Current (1) conditions DC Closed Loop, DC RL = 100Ω (1) Min 50 typ 60 0.1 Max units dB Output Characteristics Ω +3.0 V mA -3.0 ±3.5 ±270 Comlinear CLC1603, CLC3603, CLC3613 Single and Triple, 1.1mA, 200MHz Amplifiers Rev 1A ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 8 Data Sheet Typical Performance Characteristics TA = 25°C, +Vs = 5V, -VS = -5V, Rf = Rg =1.2kΩ, RL = 100Ω to GND, G = 2; unless otherwise noted. Non-Inverting Frequency Response 1 0 Inverting Frequency Response 1 0 G = -1 Comlinear CLC1603, CLC3603, CLC3613 Single and Triple, 1.1mA, 200MHz Amplifiers Normalized Gain (dB) -1 -2 -3 -4 -5 Normalized Gain (dB) G=1 Rf = 2.5kΩ G=2 -1 G = -2 -2 G = -10 -3 -4 G = -5 -5 -6 -7 VOUT = 0.5Vpp 0.1 1 10 100 1000 G=5 G = 10 -6 -7 0.1 VOUT = 0.5Vpp 1 10 100 1000 Frequency (MHz) Frequency (MHz) Frequency Response vs. CL 1 0 Frequency Response vs. RL 2 RL = 5kΩ 1 Normalized Gain (dB) -2 -3 -4 -5 -6 -7 0.1 1 VOUT = 0.5Vpp CL = 500pF Rs = 5Ω CL = 100pF Rs = 15Ω CL = 50pF Rs = 15Ω CL = 20pF Rs = 20Ω 10 100 1000 Normalized Gain (dB) -1 CL = 1000pF Rs = 5Ω RL = 1kΩ 0 -1 -2 -3 -4 -5 -6 0.1 1 10 100 1000 VOUT = 0.5Vpp RL = 150Ω RL = 50Ω RL = 25Ω Frequency (MHz) Frequency (MHz) Frequency Response vs. VOUT 1 0 Frequency Response vs. Temperature 2 1 0 Normalized Gain (dB) Normalized Gain (dB) -1 VOUT = 4Vpp -2 -3 -4 -5 -6 -7 0.1 1 10 100 1000 VOUT = 1Vpp VOUT = 2Vpp -1 -2 -3 -4 -5 -6 -7 0.1 1 VOUT = 0.2Vpp + 25degC - 40degC + 85degC Rev 1A 10 100 1000 Frequency (MHz) Frequency (MHz) ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 9 Data Sheet Typical Performance Characteristics TA = 25°C, +Vs = 5V, -VS = -5V, Rf = Rg =1.2kΩ, RL = 100Ω to GND, G = 2; unless otherwise noted. Non-Inverting Frequency Response at +Vs = 5V, -VS=GND 1 0 Inverting Frequency Response at +Vs = 5V, -VS = GND 1 0 G = -1 Comlinear CLC1603, CLC3603, CLC3613 Single and Triple, 1.1mA, 200MHz Amplifiers Normalized Gain (dB) -1 -2 -3 -4 -5 Normalized Gain (dB) G=1 Rf = 2.5kΩ G=2 -1 G = -2 -2 G = -10 -3 -4 G = -5 -5 -6 -7 VOUT = 0.5Vpp 0.1 1 10 100 1000 G=5 G = 10 -6 -7 0.1 VOUT = 0.5Vpp 1 10 100 1000 Frequency (MHz) Frequency (MHz) Frequency Response vs. CL at +Vs = 5V, -VS = GND 1 0 Frequency Response vs. RL at +Vs = 5V, -VS = GND 2 RL = 5kΩ 1 Normalized Gain (dB) -2 -3 -4 -5 -6 -7 0.1 1 VOUT = 0.5Vpp CL = 500pF Rs = 5Ω CL = 100pF Rs = 15Ω CL = 50pF Rs = 15Ω CL = 20pF Rs = 20Ω 10 100 1000 Normalized Gain (dB) -1 CL = 1000pF Rs = 5Ω RL = 1kΩ 0 -1 -2 -3 -4 -5 -6 0.1 1 10 100 1000 VOUT = 0.5Vpp RL = 150Ω RL = 50Ω RL = 25Ω Frequency (MHz) Frequency (MHz) Frequency Response vs. VOUT at +Vs = 5V, -VS = GND 1 0 Frequency Response vs. Temp. at +Vs = 5V, -VS = GND 2 1 0 Normalized Gain (dB) Normalized Gain (dB) -1 VOUT = 3Vpp -2 -3 -4 -5 -6 -7 0.1 1 10 100 1000 VOUT = 1Vpp VOUT = 2Vpp -1 -2 -3 -4 -5 -6 -7 0.1 1 VOUT = 0.2Vpp + 25degC - 40degC + 85degC Rev 1A 10 100 1000 Frequency (MHz) Frequency (MHz) ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 10 Data Sheet Typical Performance Characteristics - Continued TA = 25°C, +Vs = 5V, -VS = -5V, Rf = Rg =1.2kΩ, RL = 100Ω to GND, G = 2; unless otherwise noted. Gain Flatness 0.1 0 Gain Flatness at +Vs = 5V, -VS = GND 0.1 0 Comlinear CLC1603, CLC3603, CLC3613 Single and Triple, 1.1mA, 200MHz Amplifiers Normalized Gain (dB) -0.1 -0.2 -0.3 -0.4 -0.5 0.1 1 Normalized Gain (dB) Rf = 1.1kΩ Rf = 1.2kΩ -0.1 -0.2 -0.3 -0.4 -0.5 Rf = 1.1kΩ Rf = 1.2kΩ VOUT = 2Vpp RL = 150Ω 10 100 1000 VOUT = 2Vpp RL = 150Ω 0.1 1 10 100 1000 Frequency (MHz) Frequency (MHz) CMRR vs. Frequency -20 -25 -30 -35 -40 -45 -50 -55 -60 -65 10k 100k 1M 10M 100M VS = ±5.0V PSRR vs. Frequency 0 -10 -20 CMRR (dB) PSRR (dB) -30 -40 -50 -60 -70 0.01 0.1 1 10 100 Frequency (Hz) Frequency (MHz) Closed Loop Output Impedance vs Frequency 100 VS = ±5.0V Input Voltage Noise 7 Output Resistance (Ω) Input Voltage Noise (nV/√Hz) 10 6 5 1 4 0.1 3 0.01 0.01 2 Rev 1A 0.1 1 10 100 0.0001 0.001 0.01 0.1 1001 Frequency (MHz) Frequency (MHz) ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 11 Data Sheet Typical Performance Characteristics - Continued TA = 25°C, +Vs = 5V, -VS = -5V, Rf = Rg =1.2kΩ, RL = 100Ω to GND, G = 2; unless otherwise noted. 2nd Harmonic Distortion vs. RL -40 -45 -50 -55 RL = 100Ω 3rd Harmonic Distortion vs. RL -40 -45 -50 -55 RL = 100Ω Comlinear CLC1603, CLC3603, CLC3613 Single and Triple, 1.1mA, 200MHz Amplifiers Distortion (dBc) -60 -65 -70 -75 -80 -85 -90 -95 0 5 10 15 20 VOUT = 2Vpp RL = 1kΩ Distortion (dBc) -60 -65 -70 -75 -80 -85 -90 -95 0 5 10 15 20 VOUT = 2Vpp RL = 1kΩ Frequency (MHz) Frequency (MHz) 2nd Harmonic Distortion vs. VOUT -45 -50 -55 10MHz 3rd Harmonic Distortion vs. VOUT -45 -50 -55 10MHz Distortion (dBc) -65 -70 -75 -80 -85 -90 0.5 RL = 100Ω 0.75 1 1.25 1.5 1.75 2 2.25 2.5 1MHz 5MHz Distortion (dBc) -60 -60 -65 -70 -75 -80 -85 -90 0.5 5MHz 1MHz RL = 100Ω 0.75 1 1.25 1.5 1.75 2 2.25 2.5 Output Amplitude (Vpp) Output Amplitude (Vpp) Crosstalk vs. Frequency -30 -35 -40 -45 -50 Crosstalk (dB) -55 -60 -65 -70 -75 -80 -85 -90 -95 0.1 1 10 100 VOUT = 2Vpp Rev 1A Frequency (MHz) ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 12 Data Sheet Typical Performance Characteristics - Continued TA = 25°C, +Vs = 5V, -VS = -5V, Rf = Rg =1.2kΩ, RL = 100Ω to GND, G = 2; unless otherwise noted. Small Signal Pulse Response 0.125 0.1 0.075 0.05 Large Signal Pulse Response 2.5 2 1.5 1 VOUT = 4Vpp Comlinear CLC1603, CLC3603, CLC3613 Single and Triple, 1.1mA, 200MHz Amplifiers Voltage (V) Voltage (V) 0.025 0 -0.025 -0.05 -0.075 -0.1 -0.125 0 10 20 30 40 50 60 70 80 90 100 0.5 0 -0.5 -1 -1.5 -2 -2.5 0 10 20 30 40 VOUT = 2Vpp 50 60 70 80 90 100 Time (ns) Time (ns) Small Signal Pulse Response at +Vs = 5V, -VS = GND 2.625 2.6 2.575 2.55 Large Signal Pulse Response at +Vs = 5V, -VS = GND 4 3.5 3 VOUT = 2Vpp VOUT = 1Vpp Voltage (V) 2.5 2.475 2.45 2.425 2.4 2.375 0 10 20 30 40 50 60 70 80 90 100 Voltage (V) 2.525 2.5 2 1.5 1 0 10 20 30 40 50 60 70 80 90 100 Time (ns) Time (ns) Differential Gain & Phase AC Coupled Output 0.04 0.03 Differential Gain & Phase DC Coupled Output 0.3 0.25 Diff Gain (%) / Diff Phase (°) Diff Gain (%) / Diff Phase (°) 0.02 0.01 0 -0.01 -0.02 -0.03 -0.04 -0.7 -0.5 -0.3 -0.1 0.1 Input Voltage (V) 0.3 0.5 0.7 RL = 150Ω AC coupled into 220 F DP DG 0.2 0.15 0.1 0.05 0 -0.05 -0.1 -0.15 -0.7 -0.5 -0.3 -0.1 0.1 RL = 150Ω DC coupled DG DP Rev 1A 0.3 0.5 0.7 Input Voltage (V) ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 13 Data Sheet General Information - Current Feedback Technology Advantages of CFB Technology The CLCx603 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. 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 Rf VOUT Comlinear CLC1603, CLC3603, CLC3613 Single and Triple, 1.1mA, 200MHz Amplifiers VIN Rg RL VOUT VIN =− Rf Rg + 1+ 1 Rf Zo(jω ) Eq. 2 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 noninverting 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.cadeka.com for detailed application notes, such as AN-3: The Ins and Outs of Current Feedback Amplifiers. www.cadeka.com VIN Ierr x1 Zo*Ierr Rf VOUT RL Rg VOUT VIN = 1+ Rf Rg + 1+ 1 Rf Zo(jω ) Eq. 1 Rev 1A Figure 1. Non-Inverting Gain Configuration with First Order Transfer Function ©2007-2008 CADEKA Microcircuits LLC 14 Data Sheet Application Information Basic Operation 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. +Vs 6.8μF 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. Feedback Resistor Selection 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. Comlinear CLC1603, CLC3603, CLC3613 Single and Triple, 1.1mA, 200MHz Amplifiers Input + - 0.1μF Output 0.1μF RL Rf G = 1 + (Rf/Rg) Rg -Vs 6.8μF Figure 3. Typical Non-Inverting Gain Circuit +Vs 6.8μF R1 Input Rg + - 0.1μF Output 0.1μF 6.8μF -Vs RL Rf G = - (Rf/Rg) For optimum input offset voltage set R1 = Rf || Rg Gain (V/V 1 2 5 Rf (Ω) 2.5k 1.2k 1.2k Rg (Ω) -1.2k 300 ±0.1dB BW (MHz) 42 30 8 -3dB BW (MHz) 240 200 70 Figure 4. Typical Inverting Gain Circuit Table 1: Recommended Rf vs. Gain +Vs 6.8μF Input + - 0.1μF Output 0.1μF 6.8μF -Vs RL Rf G=1 Rf is required for CFB amplifiers 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. www.cadeka.com Rev 1A Figure 5. Typical Unity Gain (G=1) Circuit ©2007-2008 CADEKA Microcircuits LLC 15 Data Sheet Driving Capacitive Loads Increased phase delay at the output due to capacitive loading can cause ringing, peaking in the frequency response, and possible unstable behavior. Use a series resistance, RS, between the amplifier and the load to help improve stability and settling performance. Refer to Figure 6. ringing. Refer to the layout considerations section for additional information regarding high speed layout techniques. Overdrive Recovery An overdrive condition is defined as the point when either one of the inputs or the output exceed their specified voltage range. Overdrive recovery is the time needed for the amplifier to return to its normal or linear operating point. The recovery time varies, based on whether the input or output is overdriven and by how much the range is exceeded. The CLCx603 Family will typically recover in less than 30ns from an overdrive condition. Figure 7 shows the CLC1603 in an overdriven condition. 1.00 0.75 0.50 Input Output 0.00 -0.25 -0.50 -0.75 -1.00 0 20 40 60 80 100 120 140 160 180 200 5 4 3 2 1 0 -1 -2 -3 -4 -5 Comlinear CLC1603, CLC3603, CLC3613 Single and Triple, 1.1mA, 200MHz Amplifiers Input + Rf Rg Rs CL RL Output 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