EL2160C EL2160C 180MHz Current Feedback Amplifier Features General Description • • • • • • • • • • The EL2160C is a current feedback operational amplifier with -3dB bandwidth of 130MHz at a gain of +2. Built using the Elantec proprietary monolithic complementary bipolar process, this amplifier uses current mode feedback to achieve more bandwidth at a given gain than a conventional voltage feedback operational amplifier. 130MHz 3dB bandwidth (AV=+2) 180MHz 3dB bandwidth (AV=+1) 0.01% differential gain, RL=500Ω 0.01° differential phase, RL=500Ω Low supply current, 8.5mA Wide supply range, ±2V to ±15V 80mA output current (peak) Low cost 1500V/µs slew rate Input common mode range to within 1.5V of supplies • 35ns settling time to 0.1% Applications • • • • • Video amplifiers Cable drivers RGB amplifiers Test equipment amplifiers Current to voltage converters The EL2160C is designed to drive a double terminated 75Ω coax cable to video levels. Differential gain and phase are excellent when driving both loads of 500Ω (<0.01%/<0.01°) and double terminated 75Ω cables (0.025%/0.1°). The amplifier can operate on any supply voltage from 4V (±2V) to 33V (±16.5V), yet consume only 8.5mA at any supply voltage. Using industry-standard pinouts, the EL2160C is available in 8-pin PDIP and SO packages, as well as a 16-pin SO (0.300”) package. All are specified for operation over the full -40°C to +85°C temperature range. For dual and quad applications, please see the EL2260C/EL2460C datasheet. Connection Diagrams Ordering Information Part No. EL2160CN Package Tape & Reel Outline# 8-Pin PDIP - MDP0031 EL2160CS-T7 8-Pin SO 7” MDP0027 EL2160CS-T13 8-Pin SO 13” MDP0027 16-Pin SO (0.300”) - MDP0027 13” MDP0027 EL2160CM EL2160CM-T13 16-Pin SO (0.300”) NC 1 16 NC NC 2 15 NC -IN 3 NC 4 14 VS+ + 13 NC 12 OUT NC 1 NC 6 11 NC -IN 2 VS- 7 10 NC +IN 3 NC 8 9 NC VS- 4 16-Pin SO (0.300”) 8 NC + 7 VS+ 6 OUT 5 NC 8-Pin PDIP/SO Note: All information contained in this data sheet has been carefully checked and is believed to be accurate as of the date of publication; however, this data sheet cannot be a “controlled document”. Current revisions, if any, to these specifications are maintained at the factory and are available upon your request. We recommend checking the revision level before finalization of your design documentation. © 2001 Elantec Semiconductor, Inc. September 26, 2001 +IN 5 EL2160C EL2160C 180MHz Current Feedback Amplifier Absolute Maximum Ratings (T Voltage between V S+ and VSVoltage between +IN and -IN Current into +IN or -IN Internal Power Dissipation Operating Ambient Temperature Range A = 25°C) +33V ±6V 10mA See Curves -40°C to +85°C Operating Junction Temperature Plastic Packages Output Current Storage Temperature Range 150°C ±50mA -65°C to +150°C Important Note: All parameters having Min/Max specifications are guaranteed. Typ values are for information purposes only. Unless otherwise noted, all tests are at the specified temperature and are pulsed tests, therefore: TJ = TC = TA. Open Loop DC Electrical Characteristics VS = ±15V, RL = 150Ω, TA = 25°C unless otherwise specified. Limits Parameter Description Typ Max 25°C 2 10 Full 10 VS = ±5V, ±15V 25°C 0.5 5 µA VS = ±5V, ±15V 25°C 5 25 µA Common Mode Rejection Ratio  VS = ±5V, ±15V 25°C -ICMR -Input Current Common Mode Rejection  VS = ±5V, ±15V 25°C 5 µA/V PSRR Power Supply Rejection Ratio  25°C -IPSR -Input Current Power Supply Rejection  25°C 5 µA/V ROL Transimpedance  VOS Input Offset Voltage TC VOS Average Offset Voltage Drift  +IIN +Input Current -IIN -Input Current CMRR Conditions VS = ±5V, ±15V Temp Min 50 75 dB 95 0.2 mV µV/°C 55 0.2 Unit dB VS = ±15V RL = 400Ω 25°C 500 2000 kΩ VS = ±5V RL = 150Ω 25°C 500 1800 kΩ 1.5 +RIN +Input Resistance 25°C 3.0 MΩ +CIN +Input Capacitance 25°C 2.5 pF CMIR Common Mode Input Range VS = ±15V 25°C ±13.5 V VS = ±5V 25°C ±3.5 V RL = 400Ω VS =±15V 25°C ±13.5 V RL = 150Ω VS =±15V 25°C ±12 V RL = 150Ω VS =±5V 25°C ±3.0 ±3.7 V VS = ±5V, 25°C 60 100 150 mA VO ISC Output Voltage Swing Output Short Circuit Current  ±12 VS = ±15V IS 1. 2. 3. 4. 5. Supply Current VS = ±15V 25°C 8.5 12.0 mA VS = ±5V 25°C 6.4 9.5 mA Measured from T MIN to TMAX VCM = ±10V for VS = ±15V and TA = 25°C, VCM = ±3V for VS = ±5V and TA = 25°C The supplies are moved from ±2.5V to ±15V VOUT = ±7V for V S = ±15V, and VOUT = ±2V for V S = ±5V A heat sink is required to keep junction temperature below absolute maximum when an output is shorted 2 Closed Loop AC Electrical Characteristics VS = ±15V, AV = +2, RF = 560Ω, RL = 150Ω, TA = 25°C unless otherwise noted. Limits Parameter BW SR Description -3dB Bandwidth  Slew Rate   Conditions Min Typ Max Unit VS = ±15V, AV = +2 130 MHz VS = ±15V, AV = +1 180 MHz VS = ±5V, AV = +2 100 MHz VS = ±5V, AV = +1 110 MHz 1500 V/µs 1500 V/µs RL = 400Ω 1000 RF = 1KΩ, RG = 110Ω RL = 400Ω tr, tf Rise Time, Fall Time  tpd Propagation Delay  OS Overshoot  VOUT = ±500mV 0 % ts 0.1% Settling Time  VOUT = ±10V AV = -1, RL = 1k 35 ns dG Differential Gain   RL = 150Ω 0.025 % RL = 500Ω 0.006 % RL = 150Ω 0.1 ° RL = 500Ω 0.005 ° dP Differential Phase   VOUT = ±500mV 1. All AC tests are performed on a “warmed up” part, except for Slew Rate, which is pulse tested 2. Slew Rate is with VOUT from +10V to -10V and measured at the 25% and 75% points 3. DC offset from -0.714V through +0.714V, AC amplitude 286mVp-p, f = 3.58MHz 3 2.7 ns 3.2 ns EL2160C EL2160C 180MHz Current Feedback Amplifier EL2160C EL2160C 180MHz Current Feedback Amplifier Typical Performance Curves Non-Inverting Frequency Response (Gain) Inverting Frequency Response (Gain) Non-Inverting Frequency Response (Phase) Inverting Frequency Response (Phase) Frequency Response for Various RL Frequency Response for Various RF and RG RF 3 dB Bandwidth vs Supply Voltage for AV = -1 Peaking vs Supply Voltage for AV = -1 4 3 dB Bandwidth vs Temperature for A V = - 1 3 dB Bandwidth vs Supply Voltage for AV = +1 Peaking vs Supply Voltage for AV = +1 3 dB Bandwidth vs Temperature for AV = +1 3 dB Bandwidth vs Supply Voltage for AV = +2 Peaking vs Supply Voltage for AV = +2 3 dB Bandwidth vs Temperature for AV = +2 3 dB Bandwidth vs Supply Voltage for AV = +10 Peaking vs Supply Voltage for AV = +10 5 3 dB Bandwidth vs Temperature for AV = +10 EL2160C EL2160C 180MHz Current Feedback Amplifier EL2160C EL2160C 180MHz Current Feedback Amplifier Frequency Response for Various CL Frequency Response for Various CIN- 2nd and 3rd Harmonic Distortion vs Frequency Transimpedance (ROL) vs Frequency Closed-Loop Output Impedance vs Frequency PSRR and CMRR vs Frequency Voltage and Current Noise vs Frequency Transimpedance (ROL) vs Die Temperature 6 Offset Voltage vs Die Temperature (4 Samples) Supply Current vs Die Temperature Supply Current vs Supply Voltage +Input Resistance vs Die Temperature Input Current vs Die Temperature +Input Bias Current vs Input Voltage Output Voltage Swing vs Die Temperature Short Circuit Current vs Die Temperature PSRR & CMRR vs Die Temperature 7 EL2160C EL2160C 180MHz Current Feedback Amplifier EL2160C EL2160C 180MHz Current Feedback Amplifier Differential Gain vs DC Input Voltage, RL = 150 Differential Gain vs DC Input Voltage, RL = 500 Slew Rate vs Supply Voltage Differential Phase vs DC Input Voltage, RL = 150 Differential Phase vs DC Input Voltage, RL = 500 Slew Rate vs Temperature Small Signal Pulse Response Large Signal Pulse Response Settling Time vs Settling Accuracy 8 Long Term Settling Error Power Dissipation (W) 1.6 Package Power Dissipation vs Ambient Temp. JEDEC JESD51-3 Low Effective Thermal Conductivity Test Board 1.4 1.344 1.2 1.250 SO16 (0.300”) θJA=93°C/W 1 PDIP8 θJA=100°C/W 0.8 781m 0.6 SO8 θJA=160°C/W 0.4 0.2 0 0 25 50 75 85 100 Ambient Temperature (°C) Burn-In Circuit EL2160C 9 125 150 EL2160C EL2160C 180MHz Current Feedback Amplifier EL2160C EL2160C 180MHz Current Feedback Amplifier Differential Gain and Phase Test Circuit Simplified Schematic (One Amplifier) 10 Applications Information Product Description Capacitance at the Inverting Input The EL2160C is a current mode feedback amplifier that offers wide bandwidth and good video specifications at a moderately low supply current. It is built using Elantec's proprietary complimentary bipolar process and is offered in industry standard pin-outs. Due to the current feedback architecture, the EL2160C closed-loop 3dB bandwidth is dependent on the value of the feedback resistor. First the desired bandwidth is selected by choosing the feedback resistor, RF, and then the gain is set by picking the gain resistor, RG. The curves at the beginning of the Typical Performance Curves section show the effect of varying both RF and RG. The 3dB bandwidth is somewhat dependent on the power supply voltage. As the supply voltage is decreased, internal junction capacitances increase, causing a reduction in closed loop bandwidth. To compensate for this, smaller values of feedback resistor can be used at lower supply voltages. Due to the topology of the current feedback amplifier, stray capacitance at the inverting input will affect the AC and transient performance of the EL2160C when operating in the non-inverting configuration. The characteristic curve of gain vs. frequency with variations of CIN- emphasizes this effect. The curve illustrates how the bandwidth can be extended to beyond 200MHz with some additional peaking with an additional 2pF of capacitance at the VIN- pin for the case of AV = +2. Higher values of capacitance will be required to obtain similar effects at higher gains. In the inverting gain mode, added capacitance at the inverting input has little effect since this point is at a virtual ground and stray capacitance is therefore not “seen” by the amplifier. Feedback Resistor Values The EL2160C has been designed and specified with RF=560Ω for AV = +2. This value of feedback resistor yields extremely flat frequency response with little to no peaking out to 130MHz. As is the case with all current feedback amplifiers, wider bandwidth, at the expense of slight peaking, can be obtained by reducing the value of the feedback resistor. Inversely, larger values of feedback resistor will cause rolloff to occur at a lower frequency. By reducing RF to 430Ω, bandwidth can be extended to 170MHz with under 1dB of peaking. Further reduction of RF to 360Ω increases the bandwidth to 195MHz with about 2.5dB of peaking. See the curves in the Typical Performance Curves section which show 3dB bandwidth and peaking vs. frequency for various feedback resistors and various supply voltages. Power Supply Bypassing and Printed Circuit Board Layout As with any high frequency device, good printed circuit board layout is necessary for optimum performance. Ground plane construction is highly recommended. Lead lengths should be as short as possible, below ¼. The power supply pins must be well bypassed to reduce the risk of oscillation. A 1.0µF tantalum capacitor in parallel with a 0.01µF ceramic capacitor is adequate for each supply pin. For good AC performance, parasitic capacitances should be kept to a minimum, especially at the inverting input (see Capacitance at the Inverting Input section). This implies keeping the ground plane away from this pin. Carbon resistors are acceptable, while use of wirewound resistors should not be used because of their parasitic inductance. Similarly, capacitors should be low inductance for best performance. Use of sockets, particularly for the SO package, should be avoided. Sockets add parasitic inductance and capacitance which will result in peaking and overshoot. Bandwidth vs Temperature Whereas many amplifier's supply current and consequently 3dB bandwidth drop off at high temperature, the EL2160C was designed to have little supply current variations with temperature. An immediate benefit from this is that the 3dB bandwidth does not drop off drastically with temperature. With VS = ±15V and AV = +2, the bandwidth only varies from 150MHz to 110MHz 11 EL2160C EL2160C 180MHz Current Feedback Amplifier EL2160C EL2160C 180MHz Current Feedback Amplifier differential (before and after the voltage step). For AV = -1, due to the inverting mode configuration, this tail does not appear since the input stage does not experience the large voltage change as in the non-inverting mode. With AV = -1, 0.01% settling time is slightly greater than 100ns. over the entire die junction temperature range of 0°C < T < 150°C. Supply Voltage Range The EL2160C has been designed to operate with supply voltages from ±2V to ±15V. Optimum bandwidth, slew rate, and video characteristics are obtained at higher supply voltages. However, at ±2V supplies, the 3dB bandwidth at AV = +2 is a respectable 70MHz. The following figure is an oscilloscope plot of the EL2160C at ±2V supplies, AV = +2, RF = RG = 560Ω, driving a load of 150Ω, showing a clean ±600mV signal at the output. Power Dissipation The EL2160C amplifier combines both high speed and large output current drive capability at a moderate supply current in very small packages. It is possible to exceed the maximum junction temperature allowed under certain supply voltage, temperature, and loading conditions. To ensure that the EL2160C remains within its absolute maximum ratings, the following discussion will help to avoid exceeding the maximum junction temperature. The maximum power dissipation allowed in a package is determined by its thermal resistance and the amount of temperature rise according to: T JMAX – T AMAX P DMAX = --------------------------------------------θ JA The maximum power dissipation actually produced by an IC is the total quiescent supply current times the total power supply voltage plus the power in the IC due to the load, or: If a single supply is desired, values from +4V to +30V can be used as long as the input common mode range is not exceeded. When using a single supply, be sure to either 1) DC bias the inputs at an appropriate common mode voltage and AC couple the signal, or 2) ensure the driving signal is within the common mode range of the EL2160C. V OUT P DMAX = 2 × VS + ( V S – V O U T ) × --------------RL where IS is the supply current. (To be more accurate, the quiescent supply current flowing in the output driver transistor should be subtracted from the first term because, under loading and due to the class AB nature of the output stage, the output driver current is now included in the second term.) Settling Characteristics The EL2160C offers superb settling characteristics to 0.1%, typically in the 35ns to 40ns range. There are no aberrations created from the input stage which often cause longer settling times in other current feedback amplifiers. The EL2160C is not slew rate limited, therefore any size step up to ±10V gives approximately the same settling time. In general, an amplifier's AC performance degrades at higher operating temperature and lower supply current. Unlike some amplifiers, the EL2160C maintains almost constant supply current over temperature so that AC performance is not degraded as much over the entire operating temperature range. Of course, this increase in performance doesn't come for free. Since the current has increased, supply voltages must be limited so that maximum power ratings are not exceeded. As can be seen from the Long Term Settling Error curve, for AV = +1, there is approximately a 0.035% residual which tails away to 0.01% in about 40µs. This is a thermal settling error caused by a power dissipation 12 The curves do not include heat removal or forcing air, or the simple fact that the package will probably be attached to a circuit board, which can also provide some form of heat removal. Larger temperature and voltage ranges are possible with heat removal and forcing air past the part. The EL2160C consumes typically 8.5mA and maximum 11.0mA. The worst case power in an IC occurs when the output voltage is at half supply, if it can go that far, or its maximum values if it cannot reach half supply. If we set the two PDMAX equations equal to each other, and solve for VS, we can get a family of curves for various loads and output voltages according to: Current Limit R L × ( T MAX -T AMAX ) V S = ---------------------------------------------------------- + ( V OUT ) ÷ [ ( 2 × I S × R L ) + V OUT ] θJ A The EL2160C has an internal current limit that protects the circuit in the event of the output being shorted to ground. This limit is set at 100mA nominally and reduces with junction temperature. At a junction temperature of 150°C, the current limits at about 65mA. If the output is shorted to ground, the power dissipation could be well over 1W. Heat removal is required in order for the EL2160C to survive an indefinite short. The following curves show supply voltage (±VS ) vs RLOAD for various output voltage swings for the 2 different packages. The curves assume worst case conditions of TA = +85°C and IS = 11mA. Supply Voltage vs RLOAD for Various V OUT (8-Pin SO Package) 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 EL2160C from the capacitive cable and allow extensive capacitive drive. However, other applications may have high capacitive loads without termination resistors. In these applications, an additional small value (5Ω–50Ω) resistor in series with the output will eliminate most peaking. The gain resistor, RG, can be chosen to make up for the gain loss created by this additional series resistor at the output. Supply Voltage vs RLOAD for Various VOUT (PDIP Package) 13 EL2160C EL2160C 180MHz Current Feedback Amplifier EL2160C EL2160C 180MHz Current Feedback Amplifier EL2160C Macromodel * Revision A, November 1993 * AC Characteristics used CIN- (pin 2) = 1 pF; RF = 560Ω * Connections: +input * | -input * | | +Vsupply * | | | -Vsupply * | | | | output * | | | | | .subckt EL2160C/EL 3 2 7 4 6 * * Input Stage * e1 10 0 3 0 1.0 vis 10 9 0V h2 9 12 vxx 1.0 r1 2 11 130 l1 11 12 25nH iinp 3 0 0.5µA iinm 2 0 5µA r12 3 0 2Meg * * Slew Rate Limiting * h1 13 0 vis 600 r2 13 14 1K d1 14 0 dclamp d2 0 14 dclamp * * High Frequency Pole * *e2 30 0 14 0 0.00166666666 l3 30 17 0.43µH c5 17 0 0.27pF r5 17 0 500 * * Transimpedance Stage * g1 0 18 17 0 1.0 ro1 18 0 2Meg cdp 18 0 2.285pF * * Output Stage * q1 4 18 19 qp q2 7 18 20 qn q3 7 19 21 qn q4 4 20 22 qp r7 21 6 4 r8 22 6 4 ios1 7 19 2mA ios2 20 4 2mA * * Supply Current * ips 7 4 3mA * * Error Terms * ivos 0 23 2mA vxx 23 0 0V e4 24 0 3 0 1.0 e5 25 0 7 0 1.0 14 e6 26 0 4 0 1.0 r9 24 23 562 r10 25 23 1K r11 26 23 1K * * Models * .model qn npn (is=5e-15 bf=100 tf=0.1ns) .model qp pnp (is=5e-15 bf=100 tf=0.1ns) .model dclamp d (is=1e-30 ibv=0.266 bv=2.24 n=4) .ends EL2160C Macromodel 15 EL2160C EL2160C 180MHz Current Feedback Amplifier EL2160C EL2160C 180MHz Current Feedback Amplifier 16 17 EL2160C EL2160C 180MHz Current Feedback Amplifier EL2160C EL2160C 180MHz Current Feedback Amplifier General Disclaimer Specifications contained in this data sheet are in effect as of the publication date shown. Elantec, Inc. reserves the right to make changes in the circuitry or specifications contained herein at any time without notice. Elantec, Inc. assumes no responsibility for the use of any circuits described herein and makes no representations that they are free from patent infringement. September 26, 2001 WARNING - Life Support Policy Elantec, Inc. products are not authorized for and should not be used within Life Support Systems without the specific written consent of Elantec, Inc. Life Support systems are equipment intended to support or sustain life and whose failure to perform when properly used in accordance with instructions provided can be reasonably expected to result in significant personal injury or death. Users contemplating application of Elantec, Inc. Products in Life Support Systems are requested to contact Elantec, Inc. factory headquarters to establish suitable terms & conditions for these applications. Elantec, Inc.’s warranty is limited to replacement of defective components and does not cover injury to persons or property or other consequential damages. Elantec Semiconductor, Inc. 675 Trade Zone Blvd. Milpitas, CA 95035 Telephone: (408) 945-1323 (888) ELANTEC Fax: (408) 945-9305 European Office: +44-118-977-6020 Japan Technical Center: +81-45-682-5820 18 Printed in U.S.A.