200MHz Current Feedback Amplifier Features General Description • • • • • The EL2070C is a wide bandwidth, fast settling monolithic amplifier incorporating a disable/enable feature. Built using an advanced complementary bipolar process, this amplifier uses current-mode feedback to achieve more bandwidth at a given gain than conventional operational amplifiers. Designed for closed-loop gains of ±1 to ±8, the EL2070C has a 200MHz -3dB bandwidth (AV = +2), and 12ns settling to 0.05% while consuming only 15mA of supply current. Furthermore, the fast disable/enable times of 200ns/100ns allow rapid analog multiplexing. • • • • • 200MHz -3dB bandwidth, AV = 2 Disable/enable 12ns settling to 0.05% VS = ±5V @ 15mA Low distortion: HD2, HD3 @ -----60dBc at 20MHz Differential gain 0.02% at NTSC, PAL Differential phase 0.01° at NTSC, PAL Overload/short-circuit protected ±1 to ±8 closed-loop gain range Low cost Applications • • • • • • • • • • Video gain block Video distribution HDTV amplifier Analog multiplexing (using disable) Power-down mode (using disable) High-speed A/D conversion D/A I-V conversion Photodiode, CCD preamps IF processors High-speed communications Ordering Information Part No. Temp. Range Package Outline # EL2070CN -40°C to +85°C 8-Pin P-DIP MDP0031 EL2070CS -40°C to +85°C 8-Lead SO MDP0027 The EL2070C is an obvious high-performance solution for video distribution and line-driving applications, especially when its disable feature can be used for fast analog multiplexing. Furthermore, the low 15mA supply current, and the very low 5mA of supply current when disabled suggest use in systems where power is critical. With differential gain/phase of 0.02%/0.01°, guaranteed video specifications, and a minimum 50mA output drive, performance in these areas is assured. The EL2070C's settling to 0.05% in 12ns, low distortion, and ability to drive capacitive loads make it an ideal flash A/D driver. The wide 200MHz bandwidth and extremely linear phase allow unmatched signal fidelity. D/A systems can also benefit from the EL2070C, especially if linearity and drive levels are important. Connection Diagrams DIP and SO Package - Top VIew 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. September 26, 2001 Manufactured under U.S. Patent No. 4,893,091 © 2001 Elantec Semiconductor, Inc. EL2070C EL2070C EL2070C EL2070C 200MHz Current Feedback Amplifier Absolute Maximum Ratings (T A = 25°C) Supply Voltage (VS) Output Current ±7V 70mA (Output is short-circuit protected to ground, however, maximum reliability is obtained if IOUT does not exceed 70mA) Common-Mode Input Voltage Differential Input Voltage Disable Input Voltage Thermal Resistance θJA = 175°C/W SO-8 ±VS See Curves Applied Output Voltage (Disabled) Power Dissipation Operating Temperature EL2070C Lead Temperature (Soldering, 5 Seconds) Junction Temperature Storage Temperature-60°C to +150°C ±VS 5V +VS, -1V θJA = 95°C/W P-DIP -40C to +85C 300°C 175°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 = ±5V, RL = 100Ω unless otherwise specified Parameter VOS Description Test Conditions Input Offset Voltage d(VOS)/dT Average Offset Voltage Drift +IIN +Input Current Temp Min 25°C [1] Typ Max Unit 2 5.5 mV TMIN 8.2 mV TMAX 9.0 mV All 10.0 40.0 µV/°C 25°C, TMAX 10 25.0 µA TMIN d(+IIN)/dT Average +Input Current Drift -IIN -Input Current [1] All 50.0 25.0°C 10 TMIN, TMAX [1] All 50.0 36.0 µA 200.0 nA/°C 30 µA 46 µA 200.0 nA/°C d(-IIN)/dT Average -Input Current Drift PSRR Power Supply Rejection Ratio All 45.0 50.0 dB CMRR Common-Mode Rejection Ratio All 40.0 50.0 dB IS Supply Current—Quiescent No Load All 16.0 20.0 mA ISOFF Supply Current—Disabled [2] All 4.0 7.0 mA +RIN +Input Resistance 25°C, TMAX 100.0 TMIN 50.0 200.0 kΩ kΩ CIN Input Capacitance All 0.5 2.0 ROUT Output Impedance (DC) All 0.1 0.2 ROUTD Output Resistance (DC) Disabled COUTD Output Capacitance (DC) Disabled CMIR Common-Mode Input Range [3] IOUT Output Current VOUT Output Voltage Swing No Load VOUTL Output Voltage Swing 100Ω All 100.0 All 2 200.0 0.5 pF Ω kΩ 2.0 pF 25°C, TMAX 2.0 2.1 TMIN 1.2 V 25°C, TMAX 50.0 70.0 mA TMIN 35.0 All 3.3 3.5 V 25°C 3.0 3.4 V V mA Open Loop DC Electrical Characteristics (Continued) VS = ±5V, RL = 100Ω unless otherwise specified Typ Max Unit -ICMR Parameter Input Current Common Mode Rejection Description Test Conditions Temp 25°C 8.0 33.0 µA/V +IPSR +Input Current Power Supply Rejection 25°C 1.0 3.6 µA/V -IPSR -Input Current Power Supply Rejection 25°C 20 24 µA/V ROL Transimpedance 25°C Min 125.0 V/mA TMIN 30.0 80.0 V/mA TMAX 140.0 ILOGIC Pin 8 Current @ 0V All 0.8 V/mA VDIS Maximum Pin 8 V to Disable All VEN Minimum Pin 8 V to Enable All 3.5 V IDIS Minimum Pin 8 I to Disable All 350.0 µA IEN Maximum Pin 8 I to Enable All 1.2 mA 0.5 V 60.0 µA 1. Measured from T MIN to TMAX. 2. Supply current when disabled is measured at the negative supply. 3. Common-mode input range for rated performance. Closed-Loop AC Electrical Characteristics VS = ±5V, RF = 250Ω, AV = +2, RL = 100Ω unless otherwise specified Parameter Description Test Conditions Temp Min Typ 200.0 Max Unit FREQUENCY RESPONSE SSBW LSBW -3dB Bandwidth (VOUT < 0.5VPP) -3dB Bandwidth (VOUT < 5.0VPP) AV = +5 25°C 150.0 TMIN 150.0 TMAX 120.0 All 35.0 MHz MHz MHz 50.0 MHz GAIN FLATNESS GFPL GFPH GFR Peaking VOUT < 0.5VPP <40MHz Peaking VOUT < 0.5VPP >40MHz Rolloff VOUT < 0.5VPP <75MHz Linear Phase Deviation VOUT < 0.5VPP <75MHz 25°C 0.0 TMIN, TMAX 25°C 0.0 TMIN, TMAX 25°C 0.6 TMIN TMAX LPD 25°C, TMIN 0.2 TMAX 0.3 dB 0.4 dB 0.5 dB 0.7 dB 1.0 dB 1.0 dB 1.3 dB 1.0 ° 1.2 ° TIME-DOMAIN RESPONSE tr1, tf1 Rise Time, Fall Time 0.5V Step All 1.6 2.4 ns tr2, tf2 Rise Time, Fall Time 5.0V Step All 6.5 10.0 ns 3 EL2070C EL2070C 200MHz Current Feedback Amplifier EL2070C EL2070C 200MHz Current Feedback Amplifier Closed-Loop AC Electrical Characteristics VS = ±5V, RF = 250Ω, AV = +2, RL = 100Ω unless otherwise specified Typ Max Unit ts1 Parameter Settling Time to 0.1% Description 2.0V Step Test Conditions Temp All Min 10.0 13.0 ns ts2 Settling Time to 0.05% 2.0V Step All 12.0 15.0 ns OS Overshoot 0.5V Step 25°C, TMAX 0.0 10.0 % TMIN SR Slew Rate AV = +2 All AV = - 2 15.0 430.0 % 700.0 V/µs All 1600.0 V/µs 25°C -60.0 DISTORTION HD2 2nd Harmonic Distortion at 20MHz 2VPP 3rd Harmonic Distortion at 20MHz 2VPP TMIN TMAX HD3 25°C -60.0 TMIN, TMAX -45.0 dBc -40.0 dBc -45.0 dBc -50.0 dBc -50.0 dBc -154.0 dBm (1Hz) EQUIVALENT INPUT NOISE NF INV Noise Floor >100kHz Integrated Noise 100kHz to 200MHz [1] 25°C [1] -157.0 TMIN -154.0 dBm (1Hz) TMAX -153.0IV dBm (1Hz) 57.0 µV 25°C 40.0 TMIN 57.0 µV TMAX 63.0 µV IV ns DISABLE/ENABLE PERFORMANCE TOFF Disable Time to >50dB TON Enable Time OFFIso Off Isolation 10MHz 10MHz All 1000.0 All 200.0 ns 59.0 dB All 55.0 VIDEO PERFORMANCE dG Differential Gain [2] NTSC/PAL 25°C 0.02 0.08 dP Differential Phase [2] NTSC/PAL 25°C 0.01 0.08 ° pp dG Differential Gain [2] 30MHz 25°C 0.05 0.18 % pp dP Differential Phase [2] 30MHz 25°C 0.05 0.18 VBW -0.1dB Bandwidth [2] 25°C 1. Noise Tests are performed from 5MHz to 200MHz. 2. Differential gain/phase tests are with RL = 100Ω. For other values of RL, see curves. 4 30.0 60.0 % pp ° pp MHz Typical Performance Curves Non-Inverting Frequency Response Open-Loop Transimpedance Gain and Phase Equivalent Input Noise Inverting Frequency Response Frequency Response for Various RLs 2nd and 3rd Harmonic Distortion 2-Tone 3rd Order Intermodulation Intercept Power-Supply Rejection Ratio 5 Common-Mode Rejection Ratio EL2070C EL2070C 200MHz Current Feedback Amplifier EL2070C EL2070C 200MHz Current Feedback Amplifier Settling Time Long-Term Settling Time Recommended R S vs Load Capacitance Pulse Response A V = +2 Pulse Response A V = +2 6 Settling Time vs Load Capacitance Differential Gain and Phase (3.58MHz) Forward and Reverse Gain during Disable Differential Gain and Phase (4.43MHz) Enable/Disable Response 7 Differential Gain and Phase (30MHz) EL2070C EL2070C 200MHz Current Feedback Amplifier EL2070C EL2070C 200MHz Current Feedback Amplifier Equivalent Circuit Burn-In Circuit ALL PACKAGES USE THE SAME SCHEMATIC. 8 Applications Information Theory of Operation second measurement is then made with a 0.714V DC offset (100 IRE). Differential Gain is a measure of the change in amplitude of the sine wave, and is measured in percent. Differential Phase is a measure of the change in phase, and is measured in degrees. Typically, the maximum positive and negative deviations are summed to give peak values. The EL2070C has a unity gain buffer from the noninverting input to the inverting input. The error signal of the EL2070C is a current flowing into (or out of) the inverting input. A very small change in current flowing through the inverting input will cause a large change in the output voltage. This current amplification is called the transimpedance (ROL) of the EL2070C [VOUT=(ROL) * (-IIN)]. Since ROL is very large, the current flowing into the inverting input in the steady-state (non-slewing) condition is very small. In general, a back terminated cable (75Ω in series at the drive end and 75Ω to ground at the receiving end) is preferred since the impedance match at both ends will absorb any reflections. However, when double-termination is used, the received signal is reduced by half; therefore a gain of 2 configuration is typically used to compensate for the attenuation. In a gain of 2 configuration, with output swing of 2V PP , with each backterminated load at 150Ω. The EL2070C is capable of driving up to 4 back-terminated loads with excellent video performance. Please refer to the typical curves for more information on video performance with respect to frequency, gain, and loading. Therefore we can still use op-amp assumptions as a firstorder approximation for circuit analysis, namely that: 1.The voltage across the inputs is approximately 0V. 2.The current into the inputs is approximately 0mA. Resistor Value Selection and Optimization The value of the feedback resistor (and an internal capacitor) sets the AC dynamics of the EL2070C. The nominal value for the feedback resistor is 250Ω, which is the value used for production testing. This value guarantees stability. For a given closed-loop gain the bandwidth may be increased by decreasing the feedback resistor and, conversely, the bandwidth may be decreased by increasing the feedback resistor. Capacitive Feedback The EL2070C relies on its feedback resistor for proper compensation. A reduction of the impedance of the feedback element results in less stability, eventually resulting in oscillation. Therefore, circuit implementations which have capacitive feedback should not be used because of the capacitor's impedance reduction with frequency. Similarly, oscillations can occur when using the technique of placing a capacitor in parallel with the feedback resistor to compensate for shunt capacitances from the inverting input to ground. Reducing the feedback resistor too much will result in overshoot and ringing and eventually oscillations. Increasing the feedback resistor results in a lower -3dB frequency. Attenuation at high frequency is limited by a zero in the closed-loop transfer function which results from stray capacitance between the inverting input and ground. Consequently, it is very important to keep stray capacitance to a minimum at the inverting input. Offset Adjustment Pin Output offset voltage of the EL2070C can be nulled by tying a 10k potentiometer between +VS and -VS with the slider attached to pin 1. A full-range variation of the voltage at pin 1 to ±5V results in an offset voltage adjustment of at least ±10mV. For best settling performance pin 1 should be bypassed to ground with a ceramic capacitor located near to the package, even if the offset voltage adjustment feature is not being used. Differential Gain/Phase An industry-standard method of measuring the distortion of a video component is to measure the amount of differential gain and phase error it introduces. To measure these, a 40 IREPP reference signal is applied to the device with 0V DC offset (0 IRE) at 3.58MHz for NTSC, 4.43MHz for PAL, and 30MHz for HDTV. A 9 EL2070C EL2070C 200MHz Current Feedback Amplifier EL2070C EL2070C 200MHz Current Feedback Amplifier Printed Circuit Layout As with any high frequency device, good PCB layout is necessary for optimum performance. Ground plane construction is a requirement, as is good power-supply and Offset Adjust bypassing close to the package. The inverting input is sensitive to stray capacitance, therefore connections at the inverting input should be minimal, close to the package, and constructed with as little coupling to the ground plane as possible. Capacitance at the output node will reduce stability, eventually resulting in peaking, and finally oscillation if the capacitance is large enough. The design of the EL2070C allows a larger capacitive load than comparable products, yet there are occasions when a series resistor before the capacitance may be needed. Please refer to the graphs to determine the proper resistor value needed. Disable/Enable Operation The EL2070C has a disable/enable control input at pin 8. The device is enabled and operates normally when pin 8 is left open or tied to pin 7. When more than 350µA is pulled from pin 8, the EL2070C is disabled. The output becomes a high impedance, the inverting input is no longer driven to the positive input voltage, and the supply current is reduced by 2/3. To make it easy to use this feature, there is an internal resistor to limit the current to a safe level (0.8mA) if pin 8 is grounded. To draw current out of pin 8 an open-collector TTL output, a 5V CMOS output, or an NPN transistor can be used. 10 EL2070C Macromodel * Revision A. March 1992 * Enhancements include PSRR, CMRR, and Slew Rate Limiting * Connections: +input * | -input * | | +Vsupply * | | | -Vsupply * | | | | output * | | | | | .subckt M2070C 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 50 l1 11 12 48nH iinp 3 0 8µA iinm 2 0 8µA * * 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 0.1µH c5 17 0 0.1pF r5 17 0 500 * * Transimpedance Stage * g1 0 18 17 0 1.0 rol 18 0 150K cdp 18 0 2.8pF * * 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 2 r8 22 6 2 ios1 7 19 2.5mA ios2 20 4 2.5mA * * Supply Current * ips 7 4 9mA * * Error Terms * ivos 0 23 5mA vxx 23 0 0V e4 24 0 3 0 1.0 e5 25 0 7 0 1.0 11 EL2070C EL2070C 200MHz Current Feedback Amplifier EL2070C EL2070C 200MHz Current Feedback Amplifier e6 26 0 4 0 1.0 r9 24 23 3K r10 25 23 1K r11 26 23 1K * * Models * .model qn npn (is=5e-15 bf=200 tf=0.05nS) .model qp pnp (is=5e-15 bf=200 tf=0.05nS) .model dclamp d(is=1e-30 ibv=0.266 bv=1.3 n=4) .ends 12 EL2070C Macromodel 13 EL2070C EL2070C 200MHz Current Feedback Amplifier EL2070C EL2070C 200MHz 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 14 Printed in U.S.A.