CLC1606

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 CLC1606 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 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 1.3GHz Current Feedback Amplifier Comlinear CLC1606 1.3GHz Current Feedback Amplifier General Description 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%. Typical Application - Driving Dual Video Loads Rev 1A Ordering Information Part Number CLC1606IST5X CLC1606ISO8 CLC1606ISO8X Package SOT23-5 SOIC-8 SOIC-8 Pb-Free Yes Yes Yes RoHS Compliant Yes Yes Yes Operating Temperature Range -40°C to +85°C -40°C to +85°C -40°C to +85°C Packaging Method Reel Rail Reel Moisture sensitivity level for all parts is MSL-1. ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com Data Sheet SOT23-5 Pin Configuration OUT -V S +IN +VS SOT23-5 Pin Assignments Pin No. Pin Name OUT -VS +IN -IN +VS Description Output Negative supply Positive input Negative input Positive supply 1 2 3 4 5 1 2 3 + 5 4 Comlinear CLC1606 1.3GHz Current Feedback Amplifier -IN SOIC Pin Configuration SOIC Pin Assignments Pin No. 1 Pin Name NC -IN1 +IN1 -VS NC OUT +VS NC Description No connect Negative input, channel 1 Positive input, channel 1 Negative supply No connect Output Positive supply No connect NC -IN1 +IN1 -V S 1 2 3 4 8 7 6 5 NC +VS OUT NC 2 3 4 5 6 7 8 Rev 1A ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 2 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 CLC1606 1.3GHz Current Feedback Amplifier Parameter Supply Voltage Input Voltage Range Continuous Output Current Min 0 -Vs -0.5V Max 14 +Vs +0.5V 120 Unit V V mA Reliability Information Parameter Junction Temperature Storage Temperature Range Lead Temperature (Soldering, 10s) Package Thermal Resistance 5-Lead SOT23 8-Lead SOIC Notes: Package thermal resistance (qJA), JDEC standard, multi-layer test boards, still air. Min -65 Typ Max 150 150 260 Unit °C °C °C °C/W °C/W 221 100 ESD Protection Product Human Body Model (HBM) Charged Device Model (CDM) SOT23-5 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 3 Data Sheet Electrical Characteristics at +5V TA = 25°C, Vs = +5V, Rf = 270Ω, RL = 150Ω to VS/2, G = 2; unless otherwise noted. symbol UGBW BWSS BWLS BW0.1dBSS BW0.1dBLS tR, tF tS OS SR HD2 HD3 THD IP3 DG DP en ini parameter -3dB Bandwidth -3dB Bandwidth Large Signal Bandwidth 0.1dB Gain Flatness 0.1dB Gain Flatness Rise and Fall Time Settling Time to 0.1% Overshoot Slew Rate 2nd Harmonic Distortion 3rd Harmonic Distortion Total Harmonic Distortion Third-Order Intercept Differential Gain Differential Phase Input Voltage Noise Input Current Noise conditions G = +1, Rf = 390Ω, VOUT = 0.5Vpp G = +2, VOUT = 0.5Vpp G = +2, VOUT = 1Vpp G = +2, VOUT = 0.5Vpp G = +2, VOUT = 1Vpp VOUT = 1V step; (10% to 90%) VOUT = 1V step VOUT = 0.2V step 1V step 1Vpp, 5MHz 1Vpp, 5MHz 1Vpp, 5MHz 1Vpp, 10MHz NTSC (3.58MHz), AC-coupled, RL = 150Ω NTSC (3.58MHz), AC-coupled, RL = 150Ω > 1MHz > 1MHz, Inverting > 1MHz, Non-inverting Min typ 1000 900 800 132 140 0.6 10 1 1500 -74 -70 68 36 0.01 0.01 3 20 30 0 3.7 ±3.0 100 ±6.0 56 Max units MHz Frequency Domain Response Comlinear CLC1606 1.3GHz Current Feedback Amplifier MHz MHz MHz MHz ns ns % V/µs dBc dBc dB dBm % ° nV/√Hz pA/√Hz pA/√Hz mV µV/°C µA nA/°C µA nA/°C dB mA kΩ Ω pF V dB Ω V mA Time Domain Response Distortion/Noise Response DC Performance VIO dVIO Ibn dIbn Ibi dIbi PSRR IS Input Offset Voltage Average Drift Input Bias Current - Non-Inverting Average Drift Input Bias Current - Inverting Average Drift Power Supply Rejection Ratio Supply Current Non-inverting Inverting DC 55 6.5 150 70 1.0 ±1.5 Rev 1A Input Characteristics RIN CIN CMIR CMRR RO VOUT IOUT Input Resistance Input Capacitance Common Mode Input Range Common Mode Rejection Ratio Output Resistance Output Voltage Swing Output Current DC Closed Loop, DC RL = 150Ω 50 0.1 ±1.5 ±120 Output Characteristics ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 4 Data Sheet Electrical Characteristics at ±5V TA = 25°C, Vs = ±5V, Rf = 270Ω, RL = 150Ω, G = 2; unless otherwise noted. symbol UGBW BWSS BWLS BW0.1dBSS BW0.1dBLS tR, tF tS OS SR HD2 HD3 THD IP3 DG DP en ini parameter -3dB Bandwidth -3dB Bandwidth Large Signal Bandwidth 0.1dB Gain Flatness 0.1dB Gain Flatness Rise and Fall Time Settling Time to 0.1% Overshoot Slew Rate 2nd Harmonic Distortion 3rd Harmonic Distortion Total Harmonic Distortion Third-Order Intercept Differential Gain Differential Phase Input Voltage Noise Input Current Noise - Inverting conditions G = +1, Rf = 390Ω, VOUT = 0.5Vpp G = +2, VOUT = 0.5Vpp G = +2, VOUT = 2Vpp G = +2, VOUT = 0.5Vpp G = +2, VOUT = 2Vpp VOUT = 2V step; (10% to 90%) VOUT = 2V step VOUT = 0.2V step 2V step 2Vpp, 5MHz 2Vpp, 5MHz 2Vpp, 5MHz 2Vpp, 10MHz NTSC (3.58MHz), AC-coupled, RL = 150Ω NTSC (3.58MHz), AC-coupled, RL = 150Ω > 1MHz > 1MHz, Inverting > 1MHz, Non-inverting Min typ 1300 1200 875 150 150 0.5 13 1 3300 -71 -71 -68 39 0.01 0.01 3 20 30 Max units MHz Frequency Domain Response Comlinear CLC1606 1.3GHz Current Feedback Amplifier MHz MHz MHz MHz ns ns % V/µs dBc dBc dB dBm % ° nV/√Hz pA/√Hz pA/√Hz 10 45 50 mV µV/°C µA nA/°C µA nA/°C dB 9.5 mA kΩ k pF V dB Ω V mA Time Domain Response Distortion/Noise Response DC Performance VIO dVIO Ibn dIbn Ibi dIbi PSRR IS 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) -10 -45 -50 DC 40 0.5 3.7 ±3.0 100 ±7.0 56 50 7.5 Rev 1A Input Characteristics RIN CIN CMIR CMRR RO VOUT IOUT notes: 1. 100% tested at 25°C Input Resistance Input Capacitance Common Mode Input Range Common Mode Rejection Ratio (1) Output Resistance Output Voltage Swing Output Current Non-inverting Inverting 150 170 1.0 ±4.0 DC Closed Loop, DC RL = 150Ω (1) 40 50 0.1 Output Characteristics ±3.0 ±3.7 ±280 ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 5 Data Sheet Typical Performance Characteristics TA = 25°C, Vs = ±5V, Rf = 270Ω, RL = 150Ω, G = 2; unless otherwise noted. Non-Inverting Frequency Response 3 G=1 Rf = 499Ω G=1 Rf = 390Ω Inverting Frequency Response 3 G = -1 0 Comlinear CLC1606 1.3GHz Current Feedback Amplifier Normalized Gain (dB) Normalized Gain (dB) 0 G=2 -3 G=5 G = 10 VOUT = 0.5Vpp -9 0.1 1 10 100 1000 G = -2 -3 G = -5 G = -10 -6 VOUT = 0.5Vpp -9 0.1 1 10 100 1000 -6 Frequency (MHz) Frequency (MHz) Frequency Response vs. CL 1 0 Frequency Response vs. RL 6 5 4 Normalized Gain (dB) -1 Normalized Gain (dB) CL = 1000pF Rs = 3.3Ω CL = 500pF Rs = 5Ω CL = 100pF Rs = 10Ω CL = 50pF Rs = 15Ω VOUT = 0.5Vpp 0.1 1 CL = 20pF Rs = 20Ω 10 100 1000 3 2 1 0 -1 -2 -3 -4 -5 -6 0.1 1 10 100 1000 VOUT = 0.5Vpp RL = 100Ω RL = 50Ω RL = 25Ω -2 -3 -4 -5 -6 -7 Rev 1A Frequency (MHz) Frequency (MHz) Frequency Response vs. VOUT 3 2 1 Frequency Response vs. Temperature 2 1 0 Normalized Gain (dB) 0 -1 -2 -3 -4 -5 -6 -7 0.1 1 10 100 1000 VOUT = 1Vpp VOUT = 2Vpp VOUT = 4Vpp Normalized Gain (dB) -1 -2 -3 -4 -5 -6 -7 0.1 1 10 100 1000 10000 VOUT = 0.2Vpp + 25degC - 40degC + 85degC Frequency (MHz) Frequency (MHz) ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 6 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 1 0 G=1 Rf = 390Ω Inverting Frequency Response at VS = 5V 3 G = -1 0 Comlinear CLC1606 1.3GHz Current Feedback Amplifier Normalized Gain (dB) -1 -2 -3 -4 -5 -6 -7 -8 -9 0.1 1 10 VOUT = 0.5Vpp Normalized Gain (dB) G=2 G=5 G = -2 -3 G = -5 G = -10 -6 VOUT = 0.5Vpp -9 G = 10 100 1000 0.1 1 10 100 1000 Frequency (MHz) Frequency (MHz) Frequency Response vs. CL at VS = 5V 1 0 Frequency Response vs. RL at VS = 5V 4 3 Normalized Gain (dB) -1 Normalized Gain (dB) CL = 1000pF Rs = 3.3Ω CL = 500pF Rs = 5Ω CL = 100pF Rs = 10Ω CL = 50pF Rs = 15Ω VOUT = 0.5Vpp 0.1 1 CL = 20pF Rs = 20Ω 10 100 1000 2 1 0 -1 -2 -3 -4 -5 -6 0.1 1 10 100 1000 VOUT = 0.5Vpp RL = 100Ω RL = 50Ω RL = 25Ω -2 -3 -4 -5 -6 -7 Rev 1A Frequency (MHz) Frequency (MHz) Frequency Response vs. VOUT at VS = 5V 2 1 0 Frequency Response vs. Temperature at VS = 5V 2 1 0 Normalized Gain (dB) -1 -2 -3 -4 -5 -6 -7 0.1 1 10 100 1000 VOUT = 3Vpp VOUT = 1Vpp VOUT = 2Vpp Normalized Gain (dB) -1 -2 -3 -4 -5 -6 -7 0.1 1 10 100 1000 10000 VOUT = 0.2Vpp + 25degC - 40degC + 85degC Frequency (MHz) Frequency (MHz) ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 7 Data Sheet Typical Performance Characteristics - Continued TA = 25°C, Vs = ±5V, Rf = 270Ω, RL = 150Ω, G = 2; unless otherwise noted. Gain Flatness 1.7 1.5 1.3 Gain Flatness at VS = 5V 0.8 0.7 0.6 0.5 Comlinear CLC1606 1.3GHz Current Feedback Amplifier Normalized Gain (dB) Normalized Gain (dB) 1.1 0.9 0.7 0.5 0.3 0.1 -0.1 -0.3 -0.5 0.1 1 10 100 1000 VOUT = 2Vpp RL = 150Ω Rf = 270Ω 0.4 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 -0.4 -0.5 0.1 1 10 100 1000 VOUT = 2Vpp RL = 150Ω Rf = 270Ω Frequency (MHz) Frequency (MHz) -3dB Bandwidth vs. VOUT at G=10 600 550 -3dB Bandwidth vs. VOUT at G=10, VS = 5V 450 -3dB Bandwidth (MHz) 500 450 400 350 G = 10 300 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 -3dB Bandwidth (MHz) 400 350 300 250 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Rev 1A VOUT (VPP) VOUT (VPP) Closed Loop Output Impedance vs. Frequency 2.0 1.8 VS = ±5.0V Input Voltage Noise 20 Output Resistance (Ω) 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 10K 100K 1M 10M 100M Input Voltage Noise (nV/√Hz) 15 10 5 0 0.0001 0.001 0.01 0.1 1 10 Frequency (Hz) Frequency (MHz) ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 8 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 -55 -60 -65 RL = 150Ω 3rd Harmonic Distortion vs. RL -55 -60 -65 RL = 150Ω Comlinear CLC1606 1.3GHz Current Feedback Amplifier Distortion (dBc) -75 -80 -85 -90 -95 -100 0 5 10 15 20 VOUT = 2Vpp RL = 499Ω Distortion (dBc) -70 -70 -75 -80 -85 -90 -95 -100 0 5 10 15 20 VOUT = 2Vpp RL = 499Ω Frequency (MHz) Frequency (MHz) 2nd Harmonic Distortion vs. VOUT -60 -65 -70 -75 -80 -85 -90 0.5 RL = 150Ω 0.75 1 1.25 1.5 1.75 2 2.25 2.5 1MHz 10MHz 3rd Harmonic Distortion vs. VOUT -60 -65 -70 10MHz Distortion (dBc) Distortion (dBc) -75 -80 -85 -90 -95 0.5 RL = 150Ω 0.75 1 1.25 5MHz 5MHz 1MHz 1.5 1.75 2 2.25 2.5 Rev 1A Output Amplitude (Vpp) Output Amplitude (Vpp) CMRR vs. Frequency 0 VS = ±5.0V PSRR vs. Frequency 0 -10 -10 CMRR (dB) -30 -40 -50 -60 10k 100k 1M 10M 100M PSRR (dB) -20 -20 -30 -40 -50 -60 10K 100K 1M 10M 100M Frequency (Hz) Frequency (Hz) ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 9 Data Sheet Typical Performance Characteristics - Continued TA = 25°C, Vs = ±5V, Rf = 270Ω, RL = 150Ω, G = 2; unless otherwise noted. Small Signal Pulse Response 0.125 0.1 0.075 0.05 Small Signal Pulse Response at VS = 5V 2.625 2.6 2.575 2.55 Comlinear CLC1606 1.3GHz Current Feedback Amplifier Voltage (V) 0 -0.025 -0.05 -0.075 -0.1 -0.125 0 20 40 60 80 100 120 140 160 180 200 Voltage (V) 0.025 2.525 2.5 2.475 2.45 2.425 2.4 2.375 0 20 40 60 80 100 120 140 160 180 200 Time (ns) Time (ns) Large Signal Pulse Response 3 2 1 Large Signal Pulse Response at VS = 5V 4 3.5 3 Voltage (V) 0 -1 -2 -3 0 20 40 60 80 100 120 140 160 180 200 Voltage (V) 2.5 2 1.5 1 0 20 40 60 80 100 120 140 160 180 200 Rev 1A Time (ns) Time (ns) Differential Gain & Phase AC Coupled Output 0.02 0.015 Differential Gain & Phase DC Coupled Output 0.06 0.05 Diff Gain (%) / Diff Phase (°) Diff Gain (%) / Diff Phase (°) 0.01 0.005 0 -0.005 -0.01 -0.015 -0.7 -0.5 -0.3 -0.1 0.1 0.3 0.5 0.7 RL = 150Ω AC coupled DG DP 0.04 0.03 0.02 0.01 0 -0.01 -0.02 -0.7 -0.5 -0.3 -0.1 RL = 150Ω DC coupled DG DP 0.1 0.3 0.5 0.7 Input Voltage (V) Input Voltage (V) ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 10 Data Sheet Typical Performance Characteristics - Continued TA = 25°C, Vs = ±5V, Rf = 270Ω, RL = 150Ω, G = 2; unless otherwise noted. Differential Gain & Phase AC Coupled Output at VS = ±2.5V 0.01 0.005 Differential Gain & Phase DC Coupled at VS = ±2.5V 0.05 0.04 Comlinear CLC1606 1.3GHz Current Feedback Amplifier Diff Gain (%) / Diff Phase (°) Diff Gain (%) / Diff Phase (°) 0 -0.005 -0.01 -0.015 -0.02 -0.025 -0.03 -0.35 DP 0.03 0.02 0.01 0 -0.01 -0.02 -0.03 -0.04 RL = 150Ω DC coupled -0.25 -0.15 -0.05 DG DP DG RL = 150Ω AC DC coupled -0.25 -0.15 -0.05 0.05 0.15 0.25 0.35 -0.35 0.05 0.15 0.25 0.35 Input Voltage (V) Input Voltage (V) Rev 1A ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 11 Data Sheet General Information - Current Feedback Technology Advantages of CFB Technology 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. 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 CLC1606 1.3GHz Current Feedback Amplifier 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 Rev 1A VIN Ierr x1 Zo*Ierr Rf VOUT RL Rg VOUT VIN = 1+ Rf Rg + 1+ 1 Rf Zo(jω ) Eq. 1 Figure 1. Non-Inverting Gain Configuration with First Order Transfer Function ©2007-2008 CADEKA Microcircuits LLC 12 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 CLC1606 1.3GHz Current Feedback Amplifier 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) 390 270 270 Rg (Ω) 270 67.5 ±0.1dB BW (MHz) 136 150 115 -3dB BW (MHz) 1300 1200 750 Rev 1A 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 Figure 5. Typical Unity Gain (G=1) Circuit ©2007-2008 CADEKA Microcircuits LLC 13 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 CLC1606 Family will typically recover in less than 10ns from an overdrive condition. Figure 7 shows the CLC1606 in an overdriven condition. 1.5 1 Input 6 4 Output Comlinear CLC1606 1.3GHz Current Feedback Amplifier 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