400MHz GBWP Gain-of-2 Stable Operational Amplifier Features General Description • 400MHz gain-bandwidth product • Gain-of-2 stable • Ultra low video distortion = 0.01%/0.015° @NTSC/PAL • Conventional voltage-feedback topology • Low offset voltage = 200µV • Low bias current = 2µA • Low offset current = 0.1µA • Output current = 50mA over temperature • Fast settling = 13ns to 0.1% • Low distortion = -55dB HD2, ------70dB HD3 @20MHz, 2VPP, A V = +2 The EL2074C is a precision voltage-feedback amplifier featuring a 400MHz gain-bandwidth product, fast settling time, excellent differential gain and differential phase performance, and a minimum of 50mA output current drive over temperature. EL2074C EL2074C The EL2074C is gain-of-2 stable with a -3dB bandwidth of 400MHz at AV = +2. It has a very low 200µV of input offset voltage, only 2µA of input bias current, and a fully symmetrical differential input. Like all voltage-feedback operational amplifiers, the EL2074C allows the use of reactive or non-linear components in the feedback loop. This combination of speed and versatility makes the EL2074C the ideal choice for all op-amp applications at a noise gain of 2 or greater requiring high speed and precision, including active filters, integrators, sample-and-holds, and log amps. The low distortion, high output current, and fast settling makes the EL2074C an ideal amplifier for signal-processing and digitizing systems. Applications • • • • • • • • • High resolution video Active filters/integrators High-speed signal processing ADC/DAC buffers Pulse/RF amplifiers Pin diode receivers Log amplifiers Photo multiplier amplifiers High speed sample-and-holds Connection Diagram Ordering Information Part No. Package Tape & Reel Outline # EL2074CN 8-Pin PDIP - MDP0031 EL2074CS 8-Pin SO - MDP0027 EL2074CS-T7 8-Pin SO 7” MDP0027 EL2074CS-T13 8-Pin SO 13” MDP0027 NC 1 IN- 2 IN+ 3 8 NC + 6 OUT 5 NC EL2074C (8-Pin SO & 8-Pin PDIP) 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 V- 4 7 V+ EL2074C EL2074C 400MHz GBWP Gain-of-2 Stable Operational Amplifier Absolute Maximum Ratings (T A = 25°C) Supply Voltage (VS) ±7V Common-Mode Input Differential Input Voltage Thermal Resistance (PDIP) θJA = 175°C/W 0°C to +75°C 175°C -60°C to +150°C Thermal Resistance (SO) Operating Temperature Junction Temperature Storage Temperature Output Current Output is short-circuit protected to ground, however, maximum reliability is obtained if IOUT does not exceed 70mA. ±VS 5V θJA = 95°C/W Note: See EL2071/EL2171 for Thermal Impedance curves 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 Input Offset Voltage Test Conditions VCM = 0V Temp Min 25°C Typ Max 0.2 1.5 mV 3 mV TMIN, TMAX TCVOS Average Offset Voltage Drift  All 8 Unit µV/°C IB Input Bias Current VCM = 0V All 2 6 IOS Input Offset Current VCM = 0V 25°C 0.1 1 µA 2 µA TMIN, TMAX µA PSRR Power Supply Rejection Ratio  All 60 80 CMRR Common Mode Rejection Ratio  All 65 90 IS Supply Current - Quiescent No Load RIN (diff) RIN (Differential) Open-Loop 25°C 15 CIN (diff) CIN (Differential) Open-Loop 25°C 1 pF RIN (cm) RIN (Common-Mode) 25°C 1 MΩ CIN (cm) CIN (Common-Mode) 25°C 1 pF ROUT Output Resistance 25°C 20 mΩ CMIR Common-Mode Input Range 25°C 21 TMIN, TMAX 25°C ±3 TMIN, TMAX ±2.5 ±3.5 dB dB 25 mA 25 mA kΩ V V IOUT Output Current All 50 70 mA VOUT Output Voltage Swing No Load All ±3.5 ±4 V VOUT 100 Output Voltage Swing 100Ω All ±3 ±3.6 V VOUT 50 Output Voltage Swing 50Ω All ±2.5 ±3.4 V AVOL 100 Open-Loop Gain 100Ω 25°C 500 1000 V/V TMIN, TMAX 400 AVOL 50 Open-Loop Gain 50Ω 25°C 400 TMIN, TMAX 300 V/V 800 V/V V/V eN@ > 1MHz Noise Voltage 1MHz to 100MHz 25°C 2.3 nV/√Hz iN@ > 100kHz Noise Current 100kHz to 100MHz 25°C 3.2 pA/√Hz 1. Measured from T MIN, TMAX 2. ±VCC = ±4.5V to 5.5V 3. ±VIN = ±2.5V, V OUT = 0V 2 Closed Loop AC Electrical Characteristics VS = ±5V, AV = +2, RF = RG = 250Ω, CF = 3pF, RL = 100Ω unless otherwise specified. Parameter SSBW Description Test Conditions -3dB Bandwidth AV = -1 (VOUT = 0.4VPP) AV = +2 Temp Min 25°C 25°C 250 TMIN, TMAX 250 Typ 400 MHz MHz AV = +5 25°C 100 MHz AV = +10 25°C 40 MHz 25°C 400 MHz MHz Gain-Bandwidth Product AV = +10 LSBWa -3dB Bandwidth VOUT = 2VPP  All 43 63 LSBWb -3dB Bandwidth VOUT = 5VPP  All 17 25 GFPL Peaking (<50MHz) VOUT = 0.4VPP 25°C 0 TMIN, TMAX Peaking (>50MHz) VOUT = 0.4VPP 25°C 0 TMIN, TMAX GFR Rolloff (<100MHz) Unit MHz GBWP GFPH Max 400 VOUT = 0.4VPP 25°C 0.1 TMIN, TMAX MHz 1 dB 1 dB 2 dB 2 dB 0.5 dB 0.5 dB 1.8 ° LPD Linear Phase Deviation (<100MHz) VOUT = 0.4VPP All 1 PM Phase Margin AV = +2 25°C 50 ° tr1, tf1 Rise Time, Fall Time 0.4V Step, AV = +2 25°C 1.8 ns tr2, tf2 Rise Time, Fall Time 5V Step, AV = +2 25°C 8 ns ts1 Settling to 0.1% (AV = -1) 2V Step 25°C 13 ns ts2 Settling to 0.01% (AV = -1) 2V Step 25°C 25 ns OS Overshoot 2V Step 25°C 5 % SR Slew Rate 2V Step All 400 V/µs HD2a 2nd Harmonic Distortion @ 10MHz, AV = +2 25°C -65 -55 HD2c 2nd Harmonic Distortion @ 20MHz, AV = +2 25°C -55 -45 dBc -45 dBc dBc 275 Distortion  TMIN, TMAX dBc HD3a 3rd Harmonic Distortion @ 10MHz, AV = +2 25°C -72 -60 HD3c 3rd Harmonic Distortion @ 20MHz, AV = +2 25°C -70 -60 dBc -60 dBc %pp TMIN, TMAX Video Performance  dG Differential Gain NTSC 25°C 0.01 0.05 dP Differential Phase NTSC 25°C 0.015 0.05 dG Differential Gain 30MHz 25°C 0.1 dP Differential Phase 30MHz VBW ±0.1 dB Bandwidth Flatness 25°C 25°C 25 °pp %pp 0.1 °pp 50 MHz 1. Large-signal bandwidth calculated using LSBW = Slew Rate / 2π VPEAK 2. All distortion measurements are made with VOUT = 2VPP, RL = 100Ω 3. Video performance measured at AV = +2 with 2 times normal video level across RL = 100Ω. This corresponds to standard video levels across a backterminated 50Ω load, i.e., 0–100 IRE, 40IREpp giving a 1VPP video signal across the 50Ω load. For other values of RL, see curves 3 EL2074C EL2074C 400MHz GBWP Gain-of-2 Stable Operational Amplifier EL2074C EL2074C 400MHz GBWP Gain-of-2 Stable Operational Amplifier Typical Performance Curves Non-Inverting Frequency Response Inverting Frequency Response Frequency Response for Various RLs Open Loop Gain and Phase Output Voltage Swing vs Frequency Equivalent Input Noise PSRR, CMRR, and Closed-Loop RO vs Frequency 2nd and 3rd Harmonic Distortion vs Frequency 2-Tone, 3rd Order Intermodulation Intercept 4 Series Resistor and Resulting Bandwidth vs Capacitive Load Common-Mode Rejection Ratio vs Input Common-Mode Voltage Bias and Offset Current vs Temperature Settling Time vs Output Voltage Change Bias and Offset Current vs Input Common-Mode Voltage Offset Voltage vs Temperature 5 Settling Time vs Closed-Loop Gain Supply Current vs Temperature AVOL, PSRR, and CMRR vs Temperature EL2074C EL2074C 400MHz GBWP Gain-of-2 Stable Operational Amplifier EL2074C EL2074C 400MHz GBWP Gain-of-2 Stable Operational Amplifier Small Signal Transient Response Differential Gain and Phase vs DC Input Offset at 3.58MHz Differential Gain and Phase vs Number of 150Ω Loads at 3.58MHz Large Signal Transient Response Differential Gain and Phase vs DC Input Offset at 4.43MHz Differential Gain and Phase vs DC Input Offset at 30MHz Differential Gain and Phase vs Number of 150Ω Loads at 4.43MHz Differential Gain and Phase vs Number of 150Ω Loads at 30MHz 6 Equivalent Circuit Burn-In Circuit All Packages Use The Same Schematic 7 EL2074C EL2074C 400MHz GBWP Gain-of-2 Stable Operational Amplifier EL2074C EL2074C 400MHz GBWP Gain-of-2 Stable Operational Amplifier Applications Information Product Description the gain resistor. The problem stems from the feedback and gain resistance in conjunction with the approximately 3pF of board-related parasitic capacitance from the inverting input to ground. Assuming a gain-of-2 configuration with RF = RG = 250Ω, a feedback pole occurs at 424MHz, which is equivalent to a zero in the forward path at the same frequency. This zero reduces stability by reducing the effective phase-margin from about 50° to about 30°. The EL2074C is a wideband monolithic operational amplifier built on a high-speed complementary bipolar process. The EL2074C uses a classical voltage-feedback topology which allows it to be used in a variety of applications requiring a noise gain ≥2 where current-feedback amplifiers are not appropriate because of restrictions placed upon the feedback element used with the amplifier. The conventional topology of the EL2074C allows, for example, a capacitor to be placed in the feedback path, making it an excellent choice for applications such as active filters, sample-and-holds, or integrators. Similarly, because of the ability to use diodes in the feedback network, the EL2074C is an excellent choice for applications such as log amplifiers. A common solution to this problem is to add an additional capacitor from the inverting input to the output. This capacitor, in conjunction with the parasitic capacitance, maintains a constant voltage-divider between the output and the inverting input. This technique is used for AC testing of the EL2074. A 3pF capacitor is placed in parallel with the feedback resistor for all AC tests. When this capacitor is used, it is also possible to increase the resistance values of the feedback and gain resistors without loss of stability, resulting in less loading of the EL2074C from the feedback network. The EL2074C also has excellent DC specifications: 200µV, VOS, 2µA IB, 0.1µA IOS, and 90dB of CMRR. These specifications allow the EL2074C to be used in DC-sensitive applications such as difference amplifiers. Furthermore, the current noise of the EL2074C is only 3.2pA/√Hz, making it an excellent choice for high-sensitivity transimpedance amplifier configurations. Video Performance An industry-standard method of measuring the video distortion of a component such as the EL2074C is to measure the amount of differential gain (dG) and differential phase (dP) that it introduces. To make these measurements, a 0.286VPP (40 IRE) signal is applied to the device with 0V DC offset (0 IRE) at either 3.58MHz for NTSC, 4.43MHz for PAL, or 30MHz for HDTV. A second measurement is then made at 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. Gain-Bandwidth Product The EL2074C has a gain-bandwidth product of 400MHz. For gains greater than 8, its closed-loop -3dB bandwidth is approximately equal to the gain-bandwidth product divided by the noise gain of the circuit. For gains less than 8, higher-order poles in the amplifier's transfer function contribute to even higher closed loop bandwidths. For example, the EL2074C has a -3dB bandwidth of 400MHz at a gain of +2, dropping to 200MHz at a gain of +4. It is important to note that the EL2074C has been designed so that this “extra” bandwidth in low-gain applications does not come at the expense of stability. As seen in the typical performance curves, the EL2074C in a gain of +2 only exhibits 1dB of peaking with a 100Ω load. For signal transmission and distribution, 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 halved; therefore a gain of 2 configuration is typically used to compensate for the attenuation. Parasitic Capacitances and Stability When used in positive-gain configurations, the EL2074C can be quite sensitive to parasitic capacitances at the inverting input, especially with values ≥250Ω for 8 The EL2074C has been designed to be among the best video amplifiers in the marketplace today. It has been thoroughly characterized for video performance in the topology described above, and the results have been included as minimum dG and dP specifications and as typical performance curves. In a gain of +2, driving 150Ω, with standard video test levels at the input, the EL2074C exhibits dG and dP of only 0.01% and 0.015° at NTSC and PAL. Because dG and dP vary with different DC offsets, the superior video performance of the EL2074C has been characterized over the entire DC offset range from -0.714V to +0.714V. For more information, refer to the curves of dG and dP vs DC Input Offset. in peaking, overshoot, and possible oscillation. For optimum AC performance, capacitive loads should be reduced as much as possible or isolated via a series output resistor. Coax lines can be driven, as long as they are terminated with their characteristic impedance. When properly terminated, the capacitance of coaxial cable will not add to the capacitive load seen by the amplifier. Capacitive loads greater than 10pF should be buffered with a series resistor (Rs) to isolate the load capacitance from the amplifier output. A curve of recommended Rs vs Cload has been included for reference. Values of Rs were chosen to maximize resulting bandwidth without peaking. Printed-Circuit Layout The excellent output drive capability of the EL2074C allows it to drive up to 4 back-terminated loads with excellent video performance. With 4 150Ω loads, dG and dP are only 0.15% and 0.08° at NTSC and PAL. For more information, refer to the curves for Video Performance vs Number of 150Ω Loads. As with any high-frequency device, good PCB layout is necessary for optimum performance. Ground-plane construction is highly recommended, as is good power supply bypassing. A 1 µF–10 µF tantalum capacitor is recommended in parallel with a 0.01 µF ceramic capacitor. All lead lengths should be as short as possible, and all bypass capacitors should be as close to the device pins as possible. Parasitic capacitances should be kept to an absolute minimum at both inputs and at the output. Resistor values should be kept under 1000Ω to 2000Ω because of the RC time constants associated with the parasitic capacitance. Metal-film and carbon resistors are both acceptable, use of wire-wound resistors is not recommended because of parasitic inductance. Similarly, capacitors should be low-inductance for best performance. If possible, solder the EL2074C directly to the PC board without a socket. Even high quality sockets add parasitic capacitance and inductance which can potentially degrade performance. Because of the degradation of AC performance due to parasitics, the use of surface-mount components (resistors, capacitors, etc.) is also recommended. Output Drive Capability The EL2074C has been optimized to drive 50Ω and 75Ω loads. It can easily drive 6VPP into a 50Ω load. This high output drive capability makes the EL2074C an ideal choice for RF, IF and video applications. Furthermore, the current drive of the EL2074C remains a minimum of 50mA at low temperatures. The EL2074C is currentlimited at the output, allowing it to withstand momentary shorts to ground. However, power dissipation with the output shorted can be in excess of the power-dissipation capabilities of the package. Capacitive Loads Although the EL2074C has been optimized to drive resistive loads as low as 50Ω, capacitive loads will decrease the amplifier's phase margin which may result 9 EL2074C EL2074C 400MHz GBWP Gain-of-2 Stable Operational Amplifier EL2074C EL2074C 400MHz GBWP Gain-of-2 Stable Operational Amplifier EL2074C Macromodel * * Connections: input * | -input * | | +Vsupply * | | | -Vsupply * | | | | output * | | | | | .subckt M2074 3 2 7 4 6 * *Input Stage * ie 37 4 1 mA r6 36 37 125 r7 38 37 125 rc1 7 30 200 rc2 7 39 200 q1 30 3 36 qn q2 39 2 38 qna ediff 33 0 39 30 1 rdiff 33 0 1 Meg * * Compensation Section * ga 0 34 33 0 2m rh 34 0 500K ch 34 0 0.8 pF rc 34 40 50 cc 40 0 0.05 pF * * Poles * ep 41 0 40 0 1 rpa 41 42 150 cpa 42 0 0.5 pF rpb 42 43 50 cpb 43 0 0.5 pF * * Output Stage * ios1 7 50 3.0 mA ios2 51 4 3.0 mA q3 4 43 50 qp q4 7 43 51 qn q5 7 50 52 qn q6 4 51 53 qp ros1 52 6 2 ros2 6 53 2 * Power Supply Current * ips 7 4 11.4 mA * Models * .model qna npn(is800e-18 bf170 tf0.2 ns) .model qn npn(is810e-18 bf200 tf0.2 ns) .model qp pnp(is800e-18 bf200 tf0.2 ns) .ends 10 EL2074C Macromodel 11 EL2074C EL2074C 400MHz GBWP Gain-of-2 Stable Operational Amplifier EL2074C EL2074C 400MHz GBWP Gain-of-2 Stable Operational 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 12 Printed in U.S.A.