NS ESIG WD E N FOR 67 DED 51 MEN 5166/EL M O C L E E R SEE NOT ® EL5191, EL5191A Data Sheet August 3, 2005 1GHz Current Feedback Amplifier with Enable The EL5191 and EL5191A amplifiers are of the current feedback variety and exhibit a very high bandwidth of 1GHz. This makes these amplifiers ideal for today’s high speed video and monitor applications, as well as a number of RF and IF frequency designs. FN7180.2 Features • 1GHz -3dB bandwidth • 9mA supply current • Single and dual supply operation, from 5V to 10V supply span • Fast enable/disable (EL5191A only) With a supply current of just 9mA and the ability to run from a single supply voltage from 5V to 10V, these amplifiers offer very high performance for little power consumption. • Available in SOT-23 packages The EL5191A also incorporates an enable and disable function to reduce the supply current to 100µA typical per amplifier. Allowing the CE pin to float or applying a low logic level will enable the amplifier. • Lower power, 300MHz product available (EL5193, EL5293, EL5393) The EL5191 is offered in the 5-pin SOT-23 package and the EL5191A is available in the 6-pin SOT-23 as well as the industry-standard 8-pin SO packages. Both operate over the industrial temperature range of -40°C to +85°C. Applications Ordering Information • RGB amplifiers • High speed, 600MHz product available (EL5192, EL5292, and EL5392) • Pb-Free plus anneal available (RoHS compliant) • Video amplifiers • Cable drivers PACKAGE TAPE & REEL PKG. DWG. # EL5191CS 8-Pin SO - MDP0027 EL5191CSZ (See Note) 8-Pin SO (Pb-free) - MDP0027 • Current to voltage converters EL5191CSZ-T7 (See Note) 8-Pin SO (Pb-free) 7” MDP0027 Pinouts EL5191CSZ-T13 (See Note) 8-Pin SO (Pb-free) 13” MDP0027 EL5191CW-T7 5-Pin SOT-23 7” MDP0038 EL5191CWZ-T7 (See Note) 5-Pin SOT-23 (Pb-free) 7” MDP0038 EL5191ACW-T7 6-Pin SOT-23 7” (3K pcs) MDP0038 EL5191ACW-T7A 6-Pin SOT-23 7” (250 pcs) MDP0038 IN- 2 EL5191ACWZ-T7 (See Note) 6-Pin SOT-23 (Pb-free) 7” (3K pcs) MDP0038 IN+ 3 EL5191ACWZ-T7A (See Note) 6-Pin SOT-23 (Pb-free) 7” (250 pcs) MDP0038 VS- 4 PART NUMBER • Test equipment • Instrumentation EL5191A (8-PIN SO) TOP VIEW NC 1 EL5191ACS 8-Pin SO - MDP0027 EL5191ACS-T7 8-Pin SO 7” MDP0027 EL5191ACS-T13 8-Pin SO 13” MDP0027 EL5191ACSZ (See Note) 8-Pin SO (Pb-free) - MDP0027 OUT 1 EL5191ACSZ-T7 (See Note) 8-Pin SO (Pb-free) 7” MDP0027 VS- 2 EL5191ACSZ-T13 (See Note) 8-Pin SO (Pb-free) 13” MDP0027 8 CE 7 VS+ + 6 OUT 5 NC EL5191 (5-PIN SOT-23) TOP VIEW EL5191A (6-PIN SOT-23) TOP VIEW 6 VS+ OUT 1 5 CE VS- 2 4 IN- IN+ 3 + - 5 VS+ + IN+ 3 4 IN- NOTE: Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2004, 2005. All Rights Reserved All other trademarks mentioned are the property of their respective owners. EL5191, EL5191A Absolute Maximum Ratings (TA = 25°C) Supply Voltage between VS+ and VS-. . . . . . . . . . . . . . . . . . . . .11V Maximum Continuous Output Current . . . . . . . . . . . . . . . . . . . 50mA Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . 125°C Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Curves Pin Voltages. . . . . . . . . . . . . . . . . . . . . . . . . VS- -0.5V to VS+ +0.5V Storage Temperature. . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C Ambient Operating Temperature . . . . . . . . . . . . . . . .-40°C to +85°C CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise noted, all tests are at the specified temperature and are pulsed tests, therefore: TJ = TC = TA Electrical Specifications VS+ = +5V, VS- = -5V, RF = 392Ω for AV = 1, RF = 250Ω for AV = 2, RL = 150Ω, TA = 25°C unless otherwise specified. PARAMETER DESCRIPTION CONDITIONS MIN TYP MAX UNIT AC PERFORMANCE BW -3dB Bandwidth AV = +1 1000 MHz AV = +2 600 MHz 30 MHz 2800 V/µs 7 ns BW1 0.1dB Bandwidth SR Slew Rate VO = -2.5V to +2.5V, AV = +2 tS 0.1% Settling Time VOUT = -2.5V to +2.5V, AV = -1 eN Input Voltage Noise 3.8 nV/√Hz iN- IN- Input Current Noise 25 pA/√Hz iN+ IN+ Input Current Noise 55 pA/√Hz dG Differential Gain Error (Note 1) AV = +2 0.035 % dP Differential Phase Error (Note 1) AV = +2 0.04 ° 2400 DC PERFORMANCE VOS Offset Voltage TCVOS Input Offset Voltage Temperature Coefficient ROL Transimpedance -15 Measured from TMIN to TMAX 1 15 mV 5 µV/°C 150 300 kΩ INPUT CHARACTERISTICS CMIR Common Mode Input Range ±3 ±3.3 V CMRR Common Mode Rejection Ratio 42 50 dB -ICMR - Input Current Common Mode Rejection -6 +IIN + Input Current -120 -IIN - Input Current -60 RIN Input Resistance 27 kΩ CIN Input Capacitance 0.5 pF 6 µA/V 40 120 µA 5 60 µA OUTPUT CHARACTERISTICS VO RL = 150Ω to GND ±3.4 ±3.7 V RL = 1kΩ to GND ±3.8 ±4.0 V Output Current RL = 10Ω to GND 95 120 mA ISON Supply Current - Enabled No load, VIN = 0V 8 9 11 mA ISOFF Supply Current - Disabled No load, VIN = 0V 100 150 µA IOUT Output Voltage Swing SUPPLY 2 EL5191, EL5191A Electrical Specifications VS+ = +5V, VS- = -5V, RF = 392Ω for AV = 1, RF = 250Ω for AV = 2, RL = 150Ω, TA = 25°C unless otherwise specified. (Continued) PARAMETER DESCRIPTION CONDITIONS MIN TYP 75 PSRR Power Supply Rejection Ratio DC, VS = ±4.75V to ±5.25V 55 -IPSR - Input Current Power Supply Rejection DC, VS = ±4.75V to ±5.25V -2 MAX UNIT dB 2 µA/V ENABLE (EL5191A ONLY) tEN Enable Time 40 ns tDIS Disable Time 600 ns IIHCE CE Pin Input High Current CE = VS+ 0.8 6 µA IILCE CE Pin Input Low Current CE = VS- 0 -0.1 µA VIHCE CE Input High Voltage for Power-down VILCE CE Input Low Voltage for Power-down NOTE: 1. Standard NTSC test, AC signal amplitude = 286mVP-P, f = 3.58MHz 3 VS+ - 1 V VS+ - 3 V EL5191, EL5191A Typical Performance Curves Non-Inverting Frequency Response (Gain) SOT-23 Package Non-Inverting Frequency Response (Phase) 6 90 AV = 2 0 -2 -90 AV = 1 AV = 2 Phase (°) Normalized Magnitude (dB) AV = 1 2 AV = 5 -6 AV = 5 -180 AV =A10 V AV = 10 -10 -270 RF = 390Ω RL = 150Ω -14 1M 10M 100M RF = 390Ω RL = 150Ω -360 1M 1G 10M Frequency (Hz) Inverting Frequency Response (Gain) SOT-23 Package 90 AV=-1 2 -2 AV=-2 -6 AV=-5 -10 0 Phase (°) Normalized Magnitude (dB) 1G Inverting Frequency Response (Phase) 6 AV = -1 -90 AV = -2 AV = -5 -180 -270 RF = 250Ω RL = 150Ω -14 1M 10M 100M -360 1M 1G RF = 250Ω RL = 150Ω 10M Frequency (Hz) Frequency Response for Various CIN- Frequency Response for Various RL Normalized Magnitude (dB) 2pF added 1pF added 2 -2 -10 1M 1G 6 6 -6 100M Frequency (Hz) 10 Normalized Magnitude (dB) 100M Frequency (Hz) 0pF added AV = 2 RF = 250Ω RL = 150Ω 10M 100M Frequency (Hz) 4 1G RL = 100Ω 2 RL = 150Ω RL = 500Ω -2 -6 -10 -14 1M AV = 2 RF = 250Ω 10M 100M Frequency (Hz) 1G EL5191, EL5191A Typical Performance Curves (Continued) Frequency Response for Various CL Frequency Response for Various RF 14 6 Normalized Magnitude (dB) Normalized Magnitude (dB) 150Ω 10 6pF added 6 4pF added 2 -2 -6 1M AV = 2 RF = 250Ω RL=150Ω 0pF added 10M 100M 2 250Ω -2 375Ω -6 500Ω -10 -14 1M 1G AV = 2 RG = RF RL = 150Ω 10M Frequency (Hz) Group Delay vs Frequency 1G Frequency Response for Various Common-Mode Input Voltages 3.5 6 VCM = 3V Normalized Magnitude (dB) 3 Group Delay (ns) 100M Frequency (Hz) 2.5 AV = 2 RF = 250Ω 2 AV = 1 RF = 390Ω 1.5 1 0.5 0 1M 10M 100M -2 VCM = -3V -6 -10 -14 1M 1G VCM = 0V 2 AV = 2 RF = 250Ω RL = 150Ω 10M Frequency (Hz) 100M 1G Frequency (Hz) Transimpedance (ROL) vs Frequency PSRR and CMRR vs Frequency 10M 20 0 Phase 100k -180 10k -270 Gain 1k PSRR/CMRR (dB) 0 -90 Phase (°) Magnitude (Ω) 1M PSRR+ -20 PSRR-40 -60 CMRR -360 100 1k 10k 100k 1M 10M Frequency (Hz) 5 100M 1G -80 10k 100k 1M 10M Frequency (Hz) 100M 1G EL5191, EL5191A Typical Performance Curves (Continued) -3dB Bandwidth vs Supply Voltage for NonInverting Gains -3dB Bandwidth vs Supply Voltage for Inverting Gains 1200 600 RF = 390Ω RL = 150Ω AV = -2 500 -3dB Bandwidth (MHz) -3dB Bandwidth (MHz) 1000 AV = 1 800 600 AV = 2 400 AV = 10 AV = 5 200 AV = -1 400 300 AV = -5 200 100 0 RF = 250Ω RL = 150Ω 0 5 7 6 8 9 5 10 6 Total Supply Voltage (V) Peaking vs Supply Voltage for Non-Inverting Gains 4 RF = 390Ω RL=150Ω 3.5 AV = 1 3 Peaking (dB) 3 Peaking (dB) 10 9 Peaking vs Supply Voltage for Inverting Gains 4 2.5 2 1.5 1 AV = 2 0.5 AV = -1 2 AV = -2 1 AV = -5 RF = 250Ω RL = 150Ω AV = 10 0 0 5 6 7 8 9 5 10 6 Total Supply Voltage (V) 8 9 10 Non-Inverting Frequency Response (Phase) SO8 Package Non-Inverting Frequency Response (Gain) SO8 Package 90 AV = 1 2 AV = 5 100M Frequency (Hz) 6 AV = 5 -180 -270 RF = 392Ω RL = 150Ω 10M -90 AV = 10 AV = 10 -10 AV = 2 0 Phase (°) -6 AV = 1 AV = 2 -2 -14 1M 7 Total Supply Voltage (V) 6 Normalized Magnitude (dB) 8 7 Total Supply Voltage (V) 1G 1.6G -360 1M RRFF== 392Ω 392Ω RL = 150Ω 10M 100M Frequency (Hz) 1G EL5191, EL5191A Typical Performance Curves (Continued) Inverting Frequency Response (Gain) SO8 Package Inverting Frequency Response (Phase) SO8 Package 6 90 AV = -2 AV = -1 -2 AV = -5 -6 -10 -90 AV = -5 -180 -270 -14 1M RF = 250Ω RL = 150Ω 10M 100M -360 1M 1G RF = 250Ω RL = 150Ω 10M Frequency (Hz) 100M 1G Frequency (Hz) -3dB Bandwidth vs Temperature for Non-Inverting Gains -3dB Bandwidth vs Temperature for Inverting Gains 2000 700 RF = 250Ω RL = 150Ω 600 -3dB Bandwidth (MHz) -3dB Bandwidth (MHz) AV = -2 0 Phase (°) Normalized Magnitude (dB) AV = -1 2 1500 AV=1 1000 AV=2 AV=5 500 AV=10 AV = -1 500 400 AV = -2 300 AV = -5 200 100 0 -40 10 60 110 0 -40 160 RF=250Ω RL=150Ω 10 Ambient Temperature (°C) 60 110 160 Ambient Temperature (°C) Peaking vs Temperature Voltage and Current Noise vs Frequency 3 1k RL = 150Ω Voltage Noise (nV/√Hz) Current Noise (pA/√Hz) Peaking (dB) 2.5 AV = 1 2 1.5 AV = -1 1 0.5 iN+ 100 i N- 10 eN AV = -2 0 -40 10 60 110 Ambient Temperature (°C) 7 160 1 100 1k 10k 100k Frequency (Hz) 1M 10M EL5191, EL5191A Typical Performance Curves (Continued) Supply Current vs Supply Voltage 10 10 8 Supply Current (mA) Output Impedance (Ω) Closed Loop Output Impedance vs Frequency 100 1 0.1 0.01 0.001 100 6 4 2 0 1k 100k 10M 1M Frequency (Hz) 10k 100M 1G 0 10 12 30 -30 Input Power Intercept (dBm) AV = +2 VOUT = 2VP-P RL = 100Ω -20 Harmonic Distortion (dBc) 4 6 8 Supply Voltage (V) Two-Tone 3rd Order Input Referred Intermodulation Intercept (IIP3) 2nd and 3rd Harmonic Distortion vs Frequency -10 -40 2nd Order Distortion -50 -60 -70 3rd Order Distortion -80 -90 -100 1 10 Frequency (MHz) 100 25 20 15 10 5 0 -5 -10 -15 10 200 Differential Gain/Phase vs DC Input Voltage at 3.58MHz 100 200 Differential Gain/Phase vs DC Input Voltage at 3.58MHz 0.03 AV = 2 RF = RG = 250Ω RL = 150Ω dP 0.02 dG (%) or dP (°) 0.01 AV = +2 RL = 100Ω Frequency (MHz) 0.03 dG (%) or dP (°) 2 dG -0.01 -0.03 AV = 1 RF = 375Ω RL = 500Ω dP 0.01 0 dG -0.01 -0.02 -0.03 -0.05 -1 -0.5 0 DC Input Voltage 8 0.5 1 -0.04 -1 -0.5 0 DC Input Voltage 0.5 1 EL5191, EL5191A Typical Performance Curves (Continued) Output Voltage Swing vs Frequency THD < 1% Output Voltage Swing vs Frequency THD < 0.1% 10 RL = 500Ω RL = 500Ω Output Voltage Swing (VPP) Output Voltage Swing (VPP) 10 8 RL = 150Ω 6 4 2 8 RL = 150Ω 6 4 2 AV = 2 0 1 AV = 2 0 10 Frequency (MHz) 100 200 1 Small Signal Step Response 10 Frequency (MHz) Large Signal Step Response VS = ±5V RL = 150Ω AV = 2 RF = RG = 250Ω VS = ±5V RL = 150Ω AV = 2 RF = RG = 250Ω 200mV/div 1V/div 10ns/div 10ns/div Transimpedance (ROI) Vs Temperature Settling Time vs Settling Accuracy 375 25 AV = 2 RF = RG = 250Ω RL= 150Ω VSTEP = 5VP-P output 20 350 325 15 RoI (kΩ) Settling Time (ns) 100 10 300 275 250 5 225 0 0.01 0.1 Settling Accuracy (%) 9 1 200 -40 10 60 Die Temperature (°C) 110 160 EL5191, EL5191A Typical Performance Curves (Continued) PSRR and CMRR vs Temperature ICMR and IPSR vs Temperature 90 2.5 ICMR/IPSR (µA/V) PSRR/CMRR (dB) ICMR+ 2 PSRR 70 50 CMRR 30 1.5 IPSR 1 0.5 ICMR- 0 -0.5 10 -40 10 60 110 -1 -40 160 10 Die Temperature (°C) 60 110 160 110 160 110 160 Die Temperature (°C) Offset Voltage vs Temperature Input Current vs Temperature 2 140 Input Current (µA) 120 VOS (mV) 1 0 100 80 60 IB+ 40 20 IB0 -1 -40 10 60 110 -20 -40 160 10 Die Temperature (°C) 60 Temperature (°C) Positive Input Resistance vs Temperature Supply Current vs Temperature 35 10 Supply Current (mA) 30 RIN (kΩ) 25 20 15 10 9 5 0 -40 10 60 Temperature (°C) 10 110 160 8 -40 10 60 Temperature (°C) EL5191, EL5191A Typical Performance Curves (Continued) Negative Output Swing vs Temperature for Various Loads Positive Output Swing vs Temperature for Various Loads 4.2 -3.5 4.1 -3.6 150Ω 1kΩ -3.7 VOUT (V) VOUT (V) 4 3.9 3.8 3.7 -3.8 -3.9 1kΩ -4 150Ω -4.1 3.6 3.5 -40 10 60 110 -4.2 -40 160 10 Output Current vs Temperature 110 160 Slew Rate vs Temperature 140 5000 AV = 2 RF = RG = 250Ω RL = 150Ω Sink 135 4500 Slew Rate (V/µS) IOUT (mA) 60 Temperature (°C) Temperature (°C) 130 125 Source 120 115 -40 10 60 110 160 4000 3500 3000 -40 Die Temperature (°C) 10 60 Die Temperature (°C) Enable Response Disable Response 500mV/div 500mV/div 5V/div 5V/div 20ns/div Typical Performance Curves 11 (Continued) 400ns/div 110 160 EL5191, EL5191A JEDEC JESD51-7 HIGH EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD 0.5 1.2 POWER DISSIPATION (W) POWER DISSIPATION (W) 1.4 1 909mW SO8 0.8 θJA=110°C/W 0.6 0.4 0.2 0 0 25 50 75 85 100 125 0.45 0.4 435mW 0.35 SOT23-5/6 0.3 θJA=230°C/W 0.25 0.2 0.15 0.1 0.05 0 150 JEDEC JESD51-7 HIGH EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD 0 25 AMBIENT TEMPERATURE (°C) JEDEC JESD51-3 LOW EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD 0.45 0.9 POWER DISSIPATION (W) POWER DISSIPATION (W) 1 0.8 0.7 625mW 0.6 SO8 θJA=160°C/W 0.5 0.4 0.3 0.2 0.1 0 0 25 50 75 85 100 125 AMBIENT TEMPERATURE (°C) 12 50 75 85 100 125 150 AMBIENT TEMPERATURE (°C) 150 JEDEC JESD51-3 LOW EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD 391mW 0.4 0.35 θ 0.3 JA 0.25 0.2 SO =2 T2 3 56 -5-6 °C /W 0.15 0.1 0.05 0 0 25 50 75 85 100 125 AMBIENT TEMPERATURE (°C) 150 EL5191, EL5191A Pin Descriptions 8-PIN SO 5-PIN SOT-23 6-PIN SOT-23 PIN NAME 1, 5 2 4 4 FUNCTION NC Not connected IN- Inverting input EQUIVALENT CIRCUIT VS+ IN+ IN- VS- Circuit 1 3 3 3 IN+ Non-inverting input 4 2 2 VS- Negative supply 6 1 1 OUT Output (See circuit 1) VS+ OUT VS- Circuit 2 7 5 8 6 VS+ Positive supply 5 CE Chip enable VS+ CE VS- Circuit 3 13 EL5191, EL5191A Applications Information Product Description The EL5191 is a current-feedback operational amplifier that offers a wide -3dB bandwidth of 1GHz and a low supply current of 9mA per amplifier. The EL5191 works with supply voltages ranging from a single 5V to 10V and they are also capable of swinging to within 1V of either supply on the output. Because of their current-feedback topology, the EL5191 does not have the normal gain-bandwidth product associated with voltage-feedback operational amplifiers. Instead, its -3dB bandwidth to remain relatively constant as closed-loop gain is increased. This combination of high bandwidth and low power, together with aggressive pricing make the EL5191 the ideal choice for many low-power/highbandwidth applications such as portable, handheld, or battery-powered equipment. For varying bandwidth needs, consider the EL5192 with 600MHz on a 6mA supply current or the EL5193 with 300MHz on a 4mA supply current. Versions include single, dual, and triple amp packages with 5-pin SOT-23, 16-pin QSOP, and 8-pin or 16-pin SO outlines. Power Supply Bypassing and Printed Circuit Board Layout As with any high frequency device, good printed circuit board layout is necessary for optimum performance. Low impedance ground plane construction is essential. Surface mount components are recommended, but if leaded components are used, lead lengths should be as short as possible. The power supply pins must be well bypassed to reduce the risk of oscillation. The combination of a 4.7µF tantalum capacitor in parallel with a 0.01µF capacitor has been shown to work well when placed at each supply pin. For good AC performance, parasitic capacitance should be kept to a minimum, especially at the inverting input. (See the Capacitance at the Inverting Input section) Even when ground plane construction is used, it should be removed from the area near the inverting input to minimize any stray capacitance at that node. Carbon or Metal-Film resistors are acceptable with the Metal-Film resistors giving slightly less peaking and bandwidth because of additional series inductance. Use of sockets, particularly for the SO package, should be avoided if possible. Sockets add parasitic inductance and capacitance which will result in additional peaking and overshoot. Disable/Power-Down The EL5191A amplifier can be disabled placing its output in a high impedance state. When disabled, the amplifier supply current is reduced to < 150µA. The EL5191A is disabled when its CE pin is pulled up to within 1V of the positive supply. Similarly, the amplifier is enabled by floating or pulling its CE pin to at least 3V below the positive supply. For ±5V supply, this means that an EL5191A amplifier will be 14 enabled when CE is 2V or less, and disabled when CE is above 4V. Although the logic levels are not standard TTL, this choice of logic voltages allows the EL5191A to be enabled by tying CE to ground, even in 5V single supply applications. The CE pin can be driven from CMOS outputs. Capacitance at the Inverting Input Any manufacturer’s high-speed voltage- or current-feedback amplifier can be affected by stray capacitance at the inverting input. For inverting gains, this parasitic capacitance has little effect because the inverting input is a virtual ground. But for non-inverting gains, this capacitance (in conjunction with the feedback and gain resistors) creates a pole in the feedback path of the amplifier. This pole, if low enough in frequency, has the same destabilizing effect as a zero in the forward open-loop response. The use of large value feedback and gain resistors exacerbates the problem by further lowering the pole frequency (increasing the possibility of oscillation.) The EL5191 has been optimized with a 250Ω feedback resistor. With the high bandwidth of these amplifiers, these resistor values might cause stability problems when combined with parasitic capacitance, thus ground plane is not recommended around the inverting input pin of the amplifier. Feedback Resistor Values The EL5191 has been designed and specified at a gain of +2 with RF approximately 250Ω. This value of feedback resistor gives 600MHz of -3dB bandwidth at AV = 2 with about 2dB of peaking. With AV = -2, that same RF gives 450MHz of bandwidth with 0.6dB of peaking. Since the EL5191 is a current-feedback amplifier, it is also possible to change the value of RF to get more bandwidth. As seen in the curve of Frequency Response for Various RF and RG, bandwidth and peaking can be easily modified by varying the value of the feedback resistor. Because the EL5191 is a current-feedback amplifier, its gain-bandwidth product is not a constant for different closedloop gains. This feature actually allows the EL5191 to maintain about the same -3dB bandwidth. As gain is increased, bandwidth decreases slightly while stability increases. Since the loop stability is improving with higher closed-loop gains, it becomes possible to reduce the value of RF below the specified 250Ω and still retain stability, resulting in only a slight loss of bandwidth with increased closed-loop gain. Supply Voltage Range and Single-Supply Operation The EL5191 has been designed to operate with supply voltages having a span of greater than 5V and less than 10V. In practical terms, this means that the EL5191 will operate on dual supplies ranging from ±2.5V to ±5V. With single-supply, the EL5191 will operate from 5V to 10V. EL5191, EL5191A As supply voltages continue to decrease, it becomes necessary to provide input and output voltage ranges that can get as close as possible to the supply voltages. The EL5191 has an input range which extends to within 2V of either supply. So, for example, on ±5V supplies, the EL5191 has an input range which spans ±3V. The output range of the EL5191 is also quite large, extending to within 1V of the supply rail. On a ±5V supply, the output is therefore capable of swinging from -4V to +4V. Single-supply output range is larger because of the increased negative swing due to the external pull-down resistor to ground. Video Performance For good video performance, an amplifier is required to maintain the same output impedance and the same frequency response as DC levels are changed at the output. This is especially difficult when driving a standard video load of 150Ω, because of the change in output current with DC level. Previously, good differential gain could only be achieved by running high idle currents through the output transistors (to reduce variations in output impedance.) These currents were typically comparable to the entire 9mA supply current of each EL5191 amplifier. Special circuitry has been incorporated in the EL5191 to reduce the variation of output impedance with current output. This results in dG and dP specifications of 0.035% and 0.04°, while driving 150Ω at a gain of 2. Video performance has also been measured with a 500Ω load at a gain of +1. Under these conditions, the EL5191 has dG and dP specifications of 0.02% and 0.02°, respectively. Current Limiting The EL5191 has no internal current-limiting circuitry. If the output is shorted, it is possible to exceed the Absolute Maximum Rating for output current or power dissipation, potentially resulting in the destruction of the device. Power Dissipation With the high output drive capability of the EL5191, it is possible to exceed the 125°C Absolute Maximum junction temperature under certain very high load current conditions. Generally speaking when RL falls below about 25Ω, it is important to calculate the maximum junction temperature (TJMAX) for the application to determine if power supply voltages, load conditions, or package type need to be modified for the EL5191 to remain in the safe operating area. These parameters are calculated as follows: T JMAX = T MAX + ( θ JA × n × PD MAX ) where: TMAX = Maximum ambient temperature θJA = Thermal resistance of the package n = Number of amplifiers in the package PDMAX = Maximum power dissipation of each amplifier in the package PDMAX for each amplifier can be calculated as follows: V OUTMAX PD MAX = ( 2 × V S × I SMAX ) + ( V S - V OUTMAX ) × ---------------------------R L Output Drive Capability In spite of its low 9mA of supply current, the EL5191 is capable of providing a minimum of ±95mA of output current. With a minimum of ±95mA of output drive, the EL5191 is capable of driving 50Ω loads to both rails, making it an excellent choice for driving isolation transformers in telecommunications applications. Driving Cables and Capacitive Loads When used as a cable driver, double termination is always recommended for reflection-free performance. For those applications, the back-termination series resistor will decouple the EL5191 from the cable and allow extensive capacitive drive. However, other applications may have high capacitive loads without a back-termination resistor. In these applications, a small series resistor (usually between 5Ω and 50Ω) can be placed in series with the output to eliminate most peaking. The gain resistor (RG) can then be chosen to make up for any gain loss which may be created by this additional resistor at the output. In many cases it is also possible to simply increase the value of the feedback resistor (RF) to reduce the peaking. 15 where: VS = Supply voltage ISMAX = Maximum supply current of 1A VOUTMAX = Maximum output voltage (required) RL = Load resistance EL5191, EL5191A Typical Application Circuits 0.1µF +5V IN+ VS+ OUT INVS0.1µF -5V 250Ω 5Ω 0.1µF VOUT +5V IN+ VS+ OUT 5Ω INVS0.1µF -5V 250Ω 250Ω VIN INVERTING 200mA OUTPUT CURRENT DISTRIBUTION AMPLIFIER 250Ω 250Ω 0.1µF +5V IN+ VS+ OUT INVS0.1µF 250Ω -5V 250Ω +5V 0.1µF VIN IN+ VS+ OUT IN- VOUT VS0.1µF -5V FAST-SETTLING PRECISION AMPLIFIER 16 EL5191, EL5191A Typical Application Circuits (Continued) 0.1µF 0.1µF +5V IN+ +5V IN+ VS+ VS+ OUT OUT IN- INVS- VS0.1µF 0.1µF -5V -5V 250Ω 0.1µF 120Ω 250Ω 250Ω VOUT+ 0.1µF 1kΩ +5V 240Ω 0.1µF +5V IN+ VS+ OUT IN- 0.1µF 120Ω IN+ VOUT- OUT 1kΩ VS- VS+ IN- 0.1µF -5V 250Ω VOUT VS0.1µF -5V 250Ω VIN 250Ω Transmitter 250Ω Receiver DIFFERENTIAL LINE DRIVER/RECEIVER All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems. Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 17