CLC1606IST5X

Data Sheet Comlinear CLC1606 ® 1.3GHz Current Feedback Amplifier The COMLINEAR CLC1606 is a high-performance, current feedback amplifier with superior bandwith and video specifications. The CLC1606 provides 1.3GHz unity gain bandwidth, ±0.1dB gain flatness to 150MHz, and provides 3,300V/μs slew rate exceeding the requirements of high-definition television (HDTV) and other multimedia applications. The COMLINEAR CLC1606 highperformance amplifier also provide ample output current to drive multiple video loads. The COMLINEAR CLC1606 is designed to operate from ±5V or +5V supplies. It consumes only 7.5mA of supply current. The combination of high-speed and excellent video performance make the CLC1606 well suited for use in many general purpose, high-speed applications including standard definition and high definition video. Data communications applications benefit from the CLC1606’s total harmonic distortion of -68dBc at 10MHz and fast settling time to 0.1%. 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 Typical Application - Driving Dual Video Loads Comlinear CLC1606 1.3GHz Current Feedback Amplifier General Description FEATURES n 1.2GHz -3dB bandwidth at G=2 n 3,300V/μs slew rate n 0.01%/0.01˚ differential gain/ phase error n 7.5mA supply current n 875MHz large signal bandwidth n 120mA output current (easily drives three video loads) n Fully specified at 5V and ±5V supplies n CLC1606: Pb-free SOT23-5 n CLC1606: Pb-free SOIC-8 Rev 1D Ordering Information Part Number Package Pb-Free RoHS Compliant Operating Temperature Range Packaging Method CLC1606IST5X SOT23-5 Yes Yes -40°C to +85°C Reel CLC1606ISO8 SOIC-8 Yes Yes -40°C to +85°C Rail CLC1606ISO8X SOIC-8 Yes Yes -40°C to +85°C Reel Moisture sensitivity level for all parts is MSL-1. Exar Corporation 48720 Kato Road, Fremont CA 94538, USA www.exar.com Tel. +1 510 668-7000 - Fax. +1 510 668-7001 Data Sheet SOT23-5 Pin Assignments SOT23-5 Pin Configuration 1 -V S 2 +IN 3 + 5 +VS 4 -IN - SOIC Pin Configuration Pin Name 1 OUT Output 2 -VS Negative supply 3 +IN Positive input 4 -IN Negative input 5 +VS Positive supply SOIC Pin Assignments Pin No. NC 1 8 NC -IN1 2 7 +VS +IN1 3 6 OUT -V S 4 Description Comlinear CLC1606 1.3GHz Current Feedback Amplifier OUT Pin No. 5 NC Pin Name Description 1 NC No connect 2 -IN1 Negative input, channel 1 3 +IN1 Positive input, channel 1 4 -VS Negative supply 5 NC No connect 6 OUT Output 7 +VS Positive supply 8 NC No connect Rev 1D ©2007-2013 Exar Corporation 2/18 Rev 1D 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 CLC1606 1.3GHz Current Feedback Amplifier Parameter Reliability Information Parameter Min Junction Temperature Storage Temperature Range Lead Temperature (Soldering, 10s) Package Thermal Resistance 5-Lead SOT23 8-Lead SOIC Typ -65 Max Unit 150 150 260 °C °C °C 221 100 °C/W °C/W Notes: Package thermal resistance (qJA), JDEC standard, multi-layer test boards, still air. ESD Protection Product SOT23-5 Human Body Model (HBM) Charged Device Model (CDM) 2kV 1kV (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 3/18 Typ Max Unit +85 12 °C V Rev 1D Parameter Rev 1D Data Sheet Electrical Characteristics at +5V TA = 25°C, Vs = +5V, Rf = 270Ω, RL = 150Ω to VS/2, G = 2; unless otherwise noted. Symbol Parameter Conditions Min Typ Max Units Frequency Domain Response UGBW -3dB Bandwidth 1000 MHz BWSS -3dB Bandwidth G = +2, VOUT = 0.5Vpp 900 MHz BWLS Large Signal Bandwidth G = +2, VOUT = 1Vpp 800 MHz BW0.1dBSS 0.1dB Gain Flatness G = +2, VOUT = 0.5Vpp 132 MHz BW0.1dBLS 0.1dB Gain Flatness G = +2, VOUT = 1Vpp 140 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 1V step 1500 V/µs Distortion/Noise Response HD2 2nd Harmonic Distortion 1Vpp, 5MHz -74 dBc HD3 3rd Harmonic Distortion 1Vpp, 5MHz -70 dBc THD Total Harmonic Distortion 1Vpp, 5MHz 68 dB IP3 Third-Order Intercept 1Vpp, 10MHz 36 dBm DG Differential Gain NTSC (3.58MHz), AC-coupled, RL = 150Ω 0.01 % DP Differential Phase NTSC (3.58MHz), AC-coupled, RL = 150Ω 0.01 ° en Input Voltage Noise > 1MHz 3 nV/√Hz ini Input Current Noise > 1MHz, Inverting 20 pA/√Hz > 1MHz, Non-inverting 30 pA/√Hz 0 mV 3.7 µV/°C DC Performance VIO dVIO Ibn dIbn Ibi dIbi Input Offset Voltage Average Drift Input Bias Current - Non-Inverting Average Drift Input Bias Current - Inverting Average Drift Power Supply Rejection Ratio IS Supply Current DC µA 100 nA/°C ±6.0 µA 56 nA/°C 55 dB 6.5 mA 150 kΩ Input Characteristics RIN Input Resistance CIN Input Capacitance CMIR Common Mode Input Range CMRR Common Mode Rejection Ratio Non-inverting Inverting 70 Ω 1.0 pF ±1.5 V DC 50 dB 0.1 Ω Output Characteristics RO Output Resistance Closed Loop, DC VOUT Output Voltage Swing RL = 150Ω IOUT Output Current ©2007-2013 Exar Corporation 4/18 ±1.5 V ±120 mA Rev 1D Rev 1D PSRR ±3.0 Comlinear CLC1606 1.3GHz Current Feedback Amplifier G = +1, Rf = 390Ω, VOUT = 0.5Vpp Data Sheet Electrical Characteristics at ±5V TA = 25°C, Vs = ±5V, Rf = 270Ω, RL = 150Ω, G = 2; unless otherwise noted. Symbol Parameter Conditions Min Typ Max Units Frequency Domain Response -3dB Bandwidth G = +1, Rf = 390Ω, VOUT = 0.5Vpp 1300 MHz BWSS -3dB Bandwidth G = +2, VOUT = 0.5Vpp 1200 MHz BWLS Large Signal Bandwidth G = +2, VOUT = 2Vpp 875 MHz BW0.1dBSS 0.1dB Gain Flatness G = +2, VOUT = 0.5Vpp 150 MHz BW0.1dBLS 0.1dB Gain Flatness G = +2, VOUT = 2Vpp 150 MHz Time Domain Response tR, tF Rise and Fall Time VOUT = 2V step; (10% to 90%) 0.5 ns tS Settling Time to 0.1% VOUT = 2V step 13 ns OS Overshoot VOUT = 0.2V step 1 % SR Slew Rate 2V step 3300 V/µs Distortion/Noise Response HD2 2nd Harmonic Distortion 2Vpp, 5MHz -71 dBc HD3 3rd Harmonic Distortion 2Vpp, 5MHz -71 dBc THD Total Harmonic Distortion 2Vpp, 5MHz -68 dB IP3 Third-Order Intercept 2Vpp, 10MHz 39 dBm DG Differential Gain NTSC (3.58MHz), AC-coupled, RL = 150Ω 0.01 % DP Differential Phase NTSC (3.58MHz), AC-coupled, RL = 150Ω 0.01 ° en Input Voltage Noise > 1MHz 3 nV/√Hz ini Input Current Noise - Inverting > 1MHz, Inverting 20 pA/√Hz > 1MHz, Non-inverting 30 pA/√Hz DC Performance VIO dVIO Ibn dIbn Ibi dIbi Input Offset Voltage(1) -10 0.5 -45 ±3.0 Average Drift 3.7 Input Bias Current - Non-Inverting (1) Average Drift -50 Average Drift IS Supply Current DC 40 50 µA 56 nA/°C 50 dB 7.5 (1) µA nA/°C 9.5 mA Input Characteristics RIN Input Resistance CIN Input Capacitance CMIR Common Mode Input Range CMRR Common Mode Rejection Ratio (1) Non-inverting 150 Inverting 170 k 1.0 pF DC 40 kΩ ±4.0 V 50 dB 0.1 Ω Output Characteristics RO Output Resistance Closed Loop, DC VOUT Output Voltage Swing RL = 150Ω IOUT Output Current ±3.0 (1) ±3.7 V ±280 mA Notes: 1. 100% tested at 25°C ©2007-2013 Exar Corporation 5/18 Rev 1D Rev 1D Power Supply Rejection Ratio (1) ±7.0 mV µV/°C 45 100 Input Bias Current - Inverting (1) PSRR 10 Comlinear CLC1606 1.3GHz Current Feedback Amplifier UGBW Data Sheet Typical Performance Characteristics TA = 25°C, Vs = ±5V, Rf = 270Ω, RL = 150Ω, G = 2; unless otherwise noted. Non-Inverting Frequency Response Inverting Frequency Response 0 0 Normalized Gain (dB) Normalized Gain (dB) G = -1 G=1 Rf = 499Ω G=2 -3 G=5 G = 10 -6 G = -2 G = -5 -3 G = -10 -6 VOUT = 0.5Vpp VOUT = 0.5Vpp -9 -9 0.1 1 10 100 1000 0.1 1 Frequency (MHz) 100 1000 Frequency Response vs. RL 1 6 5 0 4 Normalized Gain (dB) CL = 1000pF Rs = 3.3Ω -1 Normalized Gain (dB) 10 Frequency (MHz) Frequency Response vs. CL CL = 500pF Rs = 5Ω -2 -3 CL = 100pF Rs = 10Ω -4 CL = 50pF Rs = 15Ω -5 -6 3 2 1 0 -1 RL = 100Ω -2 RL = 50Ω -3 -4 CL = 20pF Rs = 20Ω VOUT = 0.5Vpp VOUT = 0.5Vpp -5 -7 RL = 25Ω -6 0.1 1 10 100 1000 0.1 1 10 100 1000 Rev 1D Frequency (MHz) Frequency (MHz) Frequency Response vs. VOUT Frequency Response vs. Temperature 3 2 2 1 1 0 Normalized Gain (dB) Normalized Gain (dB) Comlinear CLC1606 1.3GHz Current Feedback Amplifier 3 G=1 Rf = 390Ω 3 0 -1 VOUT = 1Vpp -2 VOUT = 2Vpp -3 -4 VOUT = 4Vpp -5 -1 + 25degC -2 - 40degC -3 + 85degC -4 -5 VOUT = 0.2Vpp -6 -6 -7 -7 0.1 1 10 100 1000 0.1 Frequency (MHz) ©2007-2013 Exar Corporation 1 10 100 1000 10000 Frequency (MHz) 6/18 Rev 1D Data Sheet Typical Performance Characteristics TA = 25°C, Vs = ±5V, Rf = 270Ω, RL = 150Ω, G = 2; unless otherwise noted. Non-Inverting Frequency Response at VS = 5V 2 Inverting Frequency Response at VS = 5V G = -1 0 G=2 Normalized Gain (dB) Normalized Gain (dB) 0 -1 -2 -3 G=5 -4 -5 G = 10 -6 G = -2 G = -5 -3 G = -10 -6 -7 VOUT = 0.5Vpp -8 VOUT = 0.5Vpp -9 -9 0.1 1 10 100 1000 0.1 1 Frequency (MHz) 100 1000 Frequency Response vs. RL at VS = 5V 1 4 3 0 2 Normalized Gain (dB) CL = 1000pF Rs = 3.3Ω -1 Normalized Gain (dB) 10 Frequency (MHz) Frequency Response vs. CL at VS = 5V CL = 500pF Rs = 5Ω -2 -3 CL = 100pF Rs = 10Ω -4 CL = 50pF Rs = 15Ω -5 -6 VOUT = 0.5Vpp 1 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 1 0 0 Normalized Gain (dB) 2 1 -1 VOUT = 1Vpp VOUT = 2Vpp -4 VOUT = 3Vpp -5 1000 Frequency Response vs. Temperature at VS = 5V 2 -3 100 Frequency (MHz) Frequency Response vs. VOUT at VS = 5V -2 10 Rev 1D Frequency (MHz) Normalized Gain (dB) Comlinear CLC1606 1.3GHz Current Feedback Amplifier 3 G=1 Rf = 390Ω 1 -1 -2 + 25degC -3 - 40degC -4 -5 -6 + 85degC 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) 7/18 Rev 1D Data Sheet Typical Performance Characteristics - Continued TA = 25°C, Vs = ±5V, Rf = 270Ω, RL = 150Ω, G = 2; unless otherwise noted. Gain Flatness Gain Flatness at VS = 5V 0.8 0.7 0.6 0.5 1.1 Normalized Gain (dB) Normalized Gain (dB) 1.3 0.9 0.7 0.5 0.3 0.1 0.4 0.3 0.2 0.1 0 -0.1 -0.2 -0.1 VOUT = 2Vpp RL = 150Ω Rf = 270Ω -0.3 VOUT = 2Vpp RL = 150Ω Rf = 270Ω -0.3 -0.4 -0.5 -0.5 0.1 1 10 100 1000 0.1 1 10 Frequency (MHz) 100 1000 Frequency (MHz) -3dB Bandwidth vs. VOUT at G=10 -3dB Bandwidth vs. VOUT at G=10, VS = 5V 600 450 -3dB Bandwidth (MHz) -3dB Bandwidth (MHz) 550 500 450 400 400 350 300 350 G = 10 300 250 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 0.0 0.5 2.0 2.5 3.0 Input Voltage Noise 2.0 20 VS = ±5.0V Input Voltage Noise (nV/√Hz) Output Resistance (Ω) 1.5 VOUT (VPP) Closed Loop Output Impedance vs. Frequency 1.8 1.0 Rev 1D VOUT (VPP) 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 10K 100K 1M 10M 10 5 0.001 0.01 0.1 1 10 Frequency (MHz) Frequency (Hz) ©2007-2013 Exar Corporation 15 0 0.0001 100M 8/18 Comlinear CLC1606 1.3GHz Current Feedback Amplifier 1.7 1.5 Rev 1D Data Sheet Typical Performance Characteristics - Continued TA = 25°C, Vs = ±5V, Rf = 270Ω, RL = 150Ω, G = 2; unless otherwise noted. 2nd Harmonic Distortion vs. RL 3rd Harmonic Distortion vs. RL -55 -60 -60 RL = 150Ω -65 RL = 150Ω -70 Distortion (dBc) Distortion (dBc) -65 -75 -80 -85 RL = 499Ω -90 -70 -75 -80 RL = 499Ω -85 -90 -95 -95 VOUT = 2Vpp -100 VOUT = 2Vpp -100 0 5 10 15 20 0 5 Frequency (MHz) 2nd Harmonic Distortion vs. VOUT 15 20 3rd Harmonic Distortion vs. VOUT -60 -60 -65 -65 -75 10MHz -70 10MHz -70 Distortion (dBc) Distortion (dBc) 10 Frequency (MHz) 5MHz -80 -75 5MHz -80 -85 1MHz -85 -90 RL = 150Ω -90 0.5 0.75 1MHz RL = 150Ω -95 1 1.25 1.5 1.75 2 2.25 2.5 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 Rev 1D Output Amplitude (Vpp) Output Amplitude (Vpp) CMRR vs. Frequency PSRR vs. Frequency 0 0 -10 -10 -20 -20 PSRR (dB) CMRR (dB) VS = ±5.0V -30 -40 -50 -30 -40 -50 -60 -60 10k 100k Comlinear CLC1606 1.3GHz Current Feedback Amplifier -55 1M 10M 10K 100M ©2007-2013 Exar Corporation 100K 1M 10M 100M Frequency (Hz) Frequency (Hz) 9/18 Rev 1D Data Sheet Typical Performance Characteristics - Continued TA = 25°C, Vs = ±5V, Rf = 270Ω, RL = 150Ω, 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) 120 140 160 180 200 Large Signal Pulse Response at VS = 5V 3 4 2 3.5 1 3 Voltage (V) Voltage (V) Large Signal Pulse Response 0 2.5 -1 2 -2 1.5 -3 1 0 20 40 60 80 100 120 140 160 180 200 0 20 40 60 120 140 160 180 200 Differential Gain & Phase DC Coupled Output 0.06 0.015 0.05 Diff Gain (%) / Diff Phase (°) 0.02 0.01 DG 0 DP -0.005 -0.01 100 Time (ns) Differential Gain & Phase AC Coupled Output 0.005 80 DP 0.04 0.03 0.02 0.01 DG 0 -0.01 RL = 150Ω AC coupled -0.015 RL = 150Ω DC coupled -0.02 -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) 10/18 Rev 1D Rev 1D Time (ns) Diff Gain (%) / Diff Phase (°) 100 Time (ns) Comlinear CLC1606 1.3GHz Current Feedback Amplifier Voltage (V) Small Signal Pulse Response Data Sheet Typical Performance Characteristics - Continued TA = 25°C, Vs = ±5V, Rf = 270Ω, RL = 150Ω, G = 2; unless otherwise noted. Differential Gain & Phase DC Coupled at VS = ±2.5V 0.05 0.005 0.04 0 Diff Gain (%) / Diff Phase (°) 0.01 DP -0.005 -0.01 -0.015 DG -0.02 -0.025 RL = 150Ω DC coupled AC -0.35 0.02 0.01 0 -0.01 DG -0.02 -0.03 -0.03 DP 0.03 RL = 150Ω DC coupled -0.04 -0.25 -0.15 -0.05 0.05 0.15 0.25 0.35 -0.35 Input Voltage (V) -0.25 -0.15 -0.05 0.05 0.15 0.25 0.35 Input Voltage (V) Comlinear CLC1606 1.3GHz Current Feedback Amplifier Diff Gain (%) / Diff Phase (°) Differential Gain & Phase AC Coupled Output at VS = ±2.5V Rev 1D ©2007-2013 Exar Corporation 11/18 Rev 1D 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 VIN 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.cadeka.com for detailed application notes, such as AN-3: The Ins and Outs of Current Feedback Amplifiers. 12/18 Rev 1D Rev 1D • Ensure proper precautions have been made for driving capacitive loads Ierr Zo*Ierr Comlinear CLC1606 1.3GHz Current Feedback Amplifier The CLC1606 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 G = - (Rf/Rg) -Vs 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 Figure 5. Typical Unity Gain (G=1) Circuit ©2007-2013 Exar Corporation Rf (Ω) Rg (Ω) ±0.1dB BW (MHz) -3dB BW (MHz) 1 390 - 136 1300 2 270 270 150 1200 5 270 67.5 115 750 Rev 1D 6.8μF 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. 13/18 Comlinear CLC1606 1.3GHz Current Feedback Amplifier 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 1D Data Sheet Driving Capacitive Loads Input + Rs - Output CL Rf RL Rg 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 CLC1606 Family will typically recover in less than 10ns from an overdrive condition. Figure 7 shows the CLC1606 in an overdriven condition. Figure 6. Addition of RS for Driving Capacitive Loads CL (pF) RS (Ω) -3dB BW (MHz) 20 20 375 100 10 180 1000 3.3 58 6 VIN = 2Vpp G=5 1 4 Input Voltage (V) Input Output 0.5 2 0 0 -0.5 -2 -1 -4 -1.5 Output Voltage (V) Table 2 provides the recommended RS for various capacitive loads. The recommended RS values result in