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 ® 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 1A 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. ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 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 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. 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 Junction Temperature Storage Temperature Range Lead Temperature (Soldering, 10s) Package Thermal Resistance 5-Lead SOT23 8-Lead SOIC Min 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 Recommended Operating Conditions Min Operating Temperature Range Supply Voltage Range -40 4.5 ©2007-2008 CADEKA Microcircuits LLC Typ Max Unit +85 12 °C V www.cadeka.com Rev 1A Parameter 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 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 ©2007-2008 CADEKA Microcircuits LLC ±1.5 V ±120 mA www.cadeka.com 4 Rev 1A 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 µV/°C 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 (1) ±3.0 ±3.7 V ±280 mA Notes: 1. 100% tested at 25°C ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 5 Rev 1A Power Supply Rejection Ratio (1) ±7.0 mV 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 1A 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 Frequency (MHz) ©2007-2008 CADEKA Microcircuits LLC 100 1000 0.1 1 10 100 1000 10000 Frequency (MHz) 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 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 1A 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 Frequency (MHz) ©2007-2008 CADEKA Microcircuits LLC 100 1000 0.1 1 10 100 1000 10000 Frequency (MHz) 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 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 1A VOUT (VPP) 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 10K 100K 1M Frequency (Hz) ©2007-2008 CADEKA Microcircuits LLC 10M 100M 15 10 5 0 0.0001 0.001 0.01 Comlinear CLC1606 1.3GHz Current Feedback Amplifier 1.7 1.5 0.1 1 10 Frequency (MHz) 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 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 1A Output Amplitude (Vpp) Output Amplitude (Vpp) CMRR vs. Frequency PSRR vs. Frequency 0 0 -10 -20 -20 PSRR (dB) CMRR (dB) VS = ±5.0V -10 -30 -40 -50 -30 -40 -50 -60 -60 10k 100k 1M Frequency (Hz) ©2007-2008 CADEKA Microcircuits LLC 10M 100M 10K 100K 1M Comlinear CLC1606 1.3GHz Current Feedback Amplifier -55 10M 100M Frequency (Hz) 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 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 Rev 1A Time (ns) Diff Gain (%) / Diff Phase (°) 100 Time (ns) 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 Input Voltage (V) ©2007-2008 CADEKA Microcircuits LLC 0.3 0.5 0.7 -0.7 -0.5 -0.3 -0.1 0.1 0.3 0.5 0.7 Input Voltage (V) www.cadeka.com Comlinear CLC1606 1.3GHz Current Feedback Amplifier Voltage (V) Small Signal Pulse Response 10 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 Input Voltage (V) 0.15 0.25 0.35 -0.35 -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 1A ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 11 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 ©2007-2008 CADEKA Microcircuits LLC 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 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 12 Rev 1A • 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 6.8μF Feedback Resistor Selection 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 Output - 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. RL 0.1μF Rf G = - (Rf/Rg) For optimum input offset voltage set R1 = Rf || Rg 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 1A 6.8μF -Vs Gain (V/V Figure 4. Typical Inverting Gain Circuit Table 1: Recommended Rf vs. Gain +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 ©2007-2008 CADEKA Microcircuits LLC 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 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. 13 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 <=0.5dB peaking in the frequency response. The Frequency Response vs. CL plot, on page 5, illustrates the response of the CLC1606 Family. 1.5 -6 0 20 40 60 80 100 120 140 160 180 200 Time (ns) Figure 7. Overdrive Recovery Table 1: Recommended RS vs. CL Parasitic Capacitance on the Inverting Input Physical connections between components create unintentional or parasitic resistive, capacitive, and inductive elements. Parasitic capacitance at the inverting input can be especially troublesome with high frequency amplifiers. A parasitic capacitance on this node will be in parallel with the gain setting resistor Rg. At high frequencies, its impedance can begin to raise the system gain by making Rg appear smaller. 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 ©2007-2008 CADEKA Microcircuits LLC Power dissipation should not be a factor when operating under the stated 1000 ohm load condition. However, applications with low impedance, DC coupled loads should be analyzed to ensure that maximum allowed junction temperature is not exceeded. Guidelines listed below can be used to verify that the particular application will not cause the device to operate beyond it’s intended operating range. Maximum power levels are set by the absolute maximum junction rating of 150°C. To calculate the junction temperature, the package thermal resistance value ThetaJA (ӨJA) is used along with the total die power dissipation. TJunction = TAmbient + (ӨJA × PD) Where TAmbient is the temperature of the working environment. www.cadeka.com 14 Rev 1A For a given load capacitance, adjust RS to optimize the tradeoff between settling time and bandwidth. In general, reducing RS will increase bandwidth at the expense of additional overshoot and ringing. Power Dissipation Comlinear CLC1606 1.3GHz Current Feedback Amplifier 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. Data Sheet PD = Psupply - Pload Psupply = Vsupply × IRMS supply Vsupply = VS+ - VSPower delivered to a purely resistive load is: Pload = ((VLOAD)RMS2)/Rloadeff The effective load resistor (Rloadeff) will need to include the effect of the feedback network. For instance, 1.5 1 SOIC-8 0.5 SOT23-5 0 -40 -20 0 20 40 60 80 Ambient Temperature (°C) Figure 8. Maximum Power Derating Rloadeff in figure 3 would be calculated as: RL || (Rf + Rg) These measurements are basic and are relatively easy to perform with standard lab equipment. For design purposes however, prior knowledge of actual signal levels and load impedance is needed to determine the dissipated power. Here, PD can be found from PD = PQuiescent + PDynamic - PLoad Quiescent power can be derived from the specified IS values along with known supply voltage, VSupply. Load power can be calculated as above with the desired signal amplitudes using: ( ILOAD)RMS = ( VLOAD)RMS / Rloadeff The dynamic power is focused primarily within the output stage driving the load. This value can be calculated as: PDYNAMIC = (VS+ - VLOAD)RMS × ( ILOAD)RMS In addition, increased airflow across the package can also help to reduce the effective ӨJA of the package. In the event the outputs are momentarily shorted to a low impedance path, internal circuitry and output metallization are set to limit and handle up to 65mA of output current. However, extended duration under these conditions may not guarantee that the maximum junction temperature (+150°C) is not exceeded. Layout Considerations General layout and supply bypassing play major roles in high frequency performance. CADEKA has evaluation boards to use as a guide for high frequency layout and as aid in device testing and characterization. Follow the steps below as a basis for high frequency layout: Assuming the load is referenced in the middle of the power rails or Vsupply/2. • Include 6.8µF and 0.1µF ceramic capacitors for power supply decoupling Figure 8 shows the maximum safe power dissipation in the package vs. the ambient temperature for the 8 and 14 lead SOIC packages. • Place the 6.8µF capacitor within 0.75 inches of the power pin • Place the 0.1µF capacitor within 0.1 inches of the power pin • Remove the ground plane under and around the part, especially near the input and output pins to reduce parasitic capacitance • Minimize all trace lengths to reduce series inductances Refer to the evaluation board layouts below for more information. ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 15 Rev 1A (VLOAD)RMS = VPEAK / √2 Better thermal ratings can be achieved by maximizing PC board metallization at the package pins. However, be careful of stray capacitance on the input pins. Comlinear CLC1606 1.3GHz Current Feedback Amplifier Supply power is calculated by the standard power equation. 2 Maximum Power Dissipation (W) In order to determine PD, the power dissipated in the load needs to be subtracted from the total power delivered by the supplies. Data Sheet Evaluation Board Information The following evaluation boards are available to aid in the testing and layout of these devices: Products Comlinear CLC1606 1.3GHz Current Feedback Amplifier Evaluation Board # CEB002 CEB003 CLC1606IST5X CLC1606ISO8X Evaluation Board Schematics Evaluation board schematics and layouts are shown in Figures 9-14. These evaluation boards are built for dual- supply operation. Follow these steps to use the board in a single-supply application: 1. Short -Vs to ground. Figure 10. CEB002 Top View 2. Use C3 and C4, if the -VS pin of the amplifier is not directly connected to the ground plane. Rev 1A Figure 11. CEB002 Bottom View Figure 9. CEB002 Schematic ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 16 Data Sheet Comlinear CLC1606 1.3GHz Current Feedback Amplifier Figure 14. CEB003 Bottom View Figure 12. CEB003 Schematic Rev 1A Figure 13. CEB003 Top View ©2007-2008 CADEKA Microcircuits LLC www.cadeka.com 17 Data Sheet Mechanical Dimensions SOT23-5 Package Comlinear CLC1606 1.3GHz Current Feedback Amplifier SOIC-8 Package Rev 1A For additional information regarding our products, please visit CADEKA at: cadeka.com CADEKA Headquarters Loveland, Colorado T: 970.663.5452 T: 877.663.5452 (toll free) CADEKA, the CADEKA logo design, COMLINEAR, the COMLINEAR logo design, and ARCTIC are trademarks or registered trademarks of CADEKA Microcircuits LLC. All other brand and product names may be trademarks of their respective companies. CADEKA reserves the right to make changes to any products and services herein at any time without notice. CADEKA does not assume any responsibility or liability arising out of the application or use of any product or service described herein, except as expressly agreed to in writing by CADEKA; nor does the purchase, lease, or use of a product or service from CADEKA convey a license under any patent rights, copyrights, trademark rights, or any other of the intellectual property rights of CADEKA or of third parties. Copyright ©2007-2008 by CADEKA Microcircuits LLC. All rights reserved. A m p l i fy t h e H u m a n E x p e r i e n c e