T NT DUC PRO LACEME r at E T OL E REP rt Cente tsc O B S E N D ED m/ pp o MM nical Su tersil.co O C E ech www.in January 1996, Rev. D NO R Data our TSheet t c I L or a S t n R o E c 8-INT 1-88 ® EL4430, EL4431 FN7167 Video Instrumentation Amplifiers Features The EL4430 and EL4431 are video instrumentation amplifiers which are ideal for line receivers, differential-tosingle-ended converters, transducer interfacing, and any situation where a differential signal must be extracted from a background of common-mode noise or DC offset. • Fully differential inputs and feedback • Differential input range of ±2V • Common-mode range of ±12V • High CMRR at 4MHz of 70dB • Stable at gains of 1, 2 These devices have two differential signal inputs and two differential feedback terminals. The FB terminal connects to the amplifier output, or a divided version of it to increase circuit gain, and the REF terminal is connected to the output ground or offset reference. The EL4430 is compensated to be stable at a gain of 1 or more, and the EL4431 for a gain of 2 or more. The amplifiers have an operational temperature of -40°C to +85°C and are packaged in plastic 8-pin DIP and SO-8. The EL4430 and EL4431 are fabricated with Elantec’s proprietary complementary bipolar process which gives excellent signal symmetry and is free from latchup. • Calibrated and clean input clipping • EL4430—80MHz @ G = 1 • EL4431—160MHz GBWP • 380V/µs slew rate • 0.02% or ° differential gain or phase • Operates on ±5 to ±15V supplies with no AC degradation Applications • Line receivers • “Loop-through” interface • Level translation Pinout • Magnetic head pre-amplification • Differential-to-single-ended conversion EL4430, EL4431 (8-PIN PDIP, SO) TOP VIEW Ordering Information PART NUMBER 1 TEMP. RANGE PACKAGE PKG. NO. EL4430CN -40°C to +85°C 8-Pin PDIP MDP0031 EL4430CS -40°C to +85°C 8-Pin SO MDP0027 EL4431CN -40°C to +85°C 8-Pin PDIP MDP0031 EL4431CS -40°C to +85°C 8-Pin SO MDP0027 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright © Intersil Americas Inc. 2003. All Rights Reserved. Elantec is a registered trademark of Elantec Semiconductor, Inc. All other trademarks mentioned are the property of their respective owners. EL4430, EL4431 Absolute Maximum Ratings (TA = 25°C) V+ VS VIN VIN IIN Positive Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . 16.5V V+ to V- Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . .33V Voltage at any Input or Feedback . . . . . . . . . . . . . . . V+ to VDifference between Pairs of Inputs or Feedback. . . . . . . . .6V Current into any Input, or Feedback Pin . . . . . . . . . . . . . 4mA IOUT PD TA TS Continuous Output Current . . . . . . . . . . . . . . . . . . . . . . 30mA Maximum Power Dissipation . . . . . . . . . . . . . . . . See Curves Operating Temperature Range . . . . . . . . . . . .-40°C to +85°C Storage Temperature Range. . . . . . . . . . . . .-60°C to +150°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 Open-Loop DC Electrical Specifications PARAMETER VDIFF Power supplies at ±5V, TA = 25°C. For the EL4431, RF = RG = 500Ω. DESCRIPTION Differential input voltage (VCM = 0) Clipping MIN TYP 2.0 2.3 V 1.8 V 0.1% nonlinearity VCM Common-mode range (VDIFF = 0) MAX UNITS VS = ±5V ±2 ±3.0 V VS = ±15V ±12 ±13.0 V VOS Input offset voltage 2 8 mV IB Input bias current (IN+, IN-, REF, and FB terminals) 12 20 µA IOS Input offset current between IN+ and IN- and between REF and FB 0.2 2 µA RIN Input resistance 100 230 kΩ CMRR Common-mode rejection ratio 70 90 dB PSRR Power supply rejection ratio 60 dB EG Gain error, excluding feedback resistors VO Output voltage swing EL4430 Output voltage swing EL4431 ISC Output short-circuit current IS Supply current, VS = ±15V 2 -1.5 -0.2 VS = ±5V ±2 ±2.8 V VS = ±15V ±12 ±12.8 V VS = ±5V ±2.5 ±3.0 V VS = ±15V ±12.5 ±13.0 V 40 90 mA 13.5 +0.5 16 % mA EL4430, EL4431 Closed-Loop AC Electrical Specifications PARAMETER BW, -3dB BW, ±0.1dB Peaking Power supplies at ±12V, TA = 25°C, RL = 500Ω for the EL4430, RL = 150Ω for the EL4431, CL = 15pF. For the EL4431, RF = RG = 500Ω. DESCRIPTION -3dB small-signal bandwidth 0.1dB flatness bandwidth Frequency response peaking MIN TYP MAX UNITS EL4430 82 MHz EL4431 80 MHz EL4430 20 MHz EL4431 14 MHz EL4430 0.6 dB EL4431 1.0 dB SR Slew rate, VOUT between -2V and +2V 380 V/µs VN Input-referred noise voltage density 26 nV/√Hz dG Differential gain error, Voffset between -0.7V and +0.7V EL4430 0.02 % EL4431, RL = 150Ω 0.04 % Differential gain error, Voffset between -0.7V and +0.7V EL4430 0.02 (°) EL4431, RL = 150Ω 0.08 (°) Settling time, to 0.1% from a 4V step EL4430 48 ns dθ TS Test Circuit 3 EL4430, EL4431 Typical Performance Curves EL4430 and EL4431 Common-Mode Rejection Ratio vs Frequency EL4430 Frequency Response vs Gain EL4430 Frequency Response for Various RL, CL VS = ±5V EL4430 Frequency Response for Various RL, CL VS = ±15V EL4431 Frequency Response vs Gain EL4431 Frequency Response for Various RL, CL VS = ±5V EL4431 Frequency Response for Various RL, CL VS = ±15V EL4430 Differential Gain and Phase vs Input Offset Voltage for VS = ±5V 4 EL4430 Differential Gain and Phase vs Input Offset Voltage for VS = ±12V EL4430 Differential Gain and Phase Error vs RL EL4430, EL4431 Typical Performance Curves (Continued) EL4431 Differential Gain and Phase vs Input Offset Voltage for VS = ±5V EL4431 Differential Gain and Phase vs Input Offset Voltage for VS = ±12V EL4430 Nonlinearity vs Input Signal Span EL4431 Differential Gain and Phase Error vs RL EL4431 Nonlinearity vs Input Signal Span EL4430 -3dB Bandwidth and Peaking vs Supply Voltage for AV = +1 EL4430 -3dB Bandwidth and Peaking vs Die Temperature for AV = +1 EL4430 Gain, -3dB Bandwidth and Peaking vs Load Resistance for AV = +1 EL4431 -3dB Bandwidth and Peaking vs Supply Voltage EL4431 -3dB Bandwidth and Peaking vs Die Temperature for AV = +2 EL4431 Gain, -3dB Bandwidth and Peaking vs Load Resistance for AV = +2 5 EL4430, EL4431 Typical Performance Curves (Continued) Slew Rate vs Supply Voltage Slew Rate vs Die Temperature Common Mode Input Range vs Supply Voltage Offset Voltage vs Die Temperature Supply Current vs Supply Voltage 6 Supply Current vs Die Temperature Input Voltage and Current Noise vs Frequency Bias Current vs Die Temperature Power Dissipation vs Ambient Temperature EL4430, EL4431 Applications Information Input Connections The EL4430 and EL4431 are designed to convert a fully differential input to a single-ended output. It has two sets of inputs; one which is connected to the signal and does not respond to its common-mode level, and another which is used to complete a feedback loop with the output. Here is a typical connection: The input transistors can be driven from resistive and capacitive sources, but are capable of oscillation when presented with an inductive input. It takes about 80nH of series inductance to make the inputs actually oscillate, equivalent to 4 of unshielded wiring or about 6 of unterminated input transmission line. The oscillation has a characteristic frequency of 500MHz. Often, placing one’s finger (via a metal probe) or an oscilloscope probe on the input will kill the oscillation. Normal high-frequency construction obviates any such problems, where the input source is reasonably close to the input. If this is not possible, one can insert series resistors of approximately 51Ω to de-Q the inputs. Signal Amplitudes The gain of the feedback divider is H. The transfer function of the part is: VOUT = AO × ((VIN+) - (VIN-) + (VREF - VFB)). VFB is connected to VOUT through a feedback network, so VFB = H × VOUT. AO is the open-loop gain of the amplifier, and is about 600 for the EL4430 and EL4431. The large value of AO drives: (VIN+) - (VIN-) + (VREF - VFB)→0. Rearranging and substituting for VFB: VOUT = ((VIN+) - (VIN-) + VREF)/H. Thus, the output is equal to the difference of the VINs and offset by VREF, all gained up by the feedback divider ratio. The input impedance of the FB terminal (equal to RIN of the input terminals) is in parallel with an RG, and raises circuit gain slightly. The EL4430 is stable for a gain of 1 (a direct connection between VOUT and FB) or more and the EL4431 for gains of 2 or more. It is important to keep the feedback divider’s impedance at the FB terminal low so that stray capacitance does not diminish the loop’s phase margin. The pole caused by the parallel of resistors RF and RG and stray capacitance should be at least 200MHz; typical strays of 3pF thus require a feedback impedance of 270Ω or less. Two 510Ω resistors are acceptable for a gain of 2; 300Ω and 2700Ω make a good gain-of-10 divider. Alternatively, a small capacitor across RF can be used to create more of a frequencycompensated divider. The value of the capacitor should scale with the parasitic capacitance at the FB terminal input. It is also practical to place small capacitors across both the feedback resistors (whose values maintain the desired gain) to swamp out parasitics. For instance, two 10pF capacitors (for a gain of 2) across equal divider resistors will dominate parasitic effects and allow a higher divider resistance. 7 Signal input common-mode voltage must be between (V-)+3V and (V+)-3V to ensure linearity. Additionally, the differential voltage on any input stage must be limited to ±6V to prevent damage. The differential signal range is ±2V in the EL4430 and EL4431. The input range is substantially constant with temperature. The Ground Pin The ground pin draws only 6µA maximum DC current, and may be biased anywhere between (V-)+2.5V and (V+)-3.5V. The ground pin is connected to the IC’s substrate and frequency compensation components. It serves as a shield within the IC and enhances CMRR over frequency, and if connected to a potential other than ground, it must be bypassed. Power Supplies The instrumentation amplifiers work well on any supplies from ±3V to ±15. The supplies may be of different voltages as long as the requirements of the Gnd pin are observed (see the Ground Pin section for a discussion). The supplies should be bypassed close to the device with short leads. 4.7µF tantalum capacitors are very good, and no smaller bypasses need be placed in parallel. Capacitors as low as 0.01µF can be used if small load currents flow. Single-polarity supplies, such as +12V with +5V can be used, where the ground pin is connected to +5V and V- to ground. The inputs and outputs will have to have their levels shifted above ground to accommodate the lack of negative supply. The dissipation of the amplifiers increases with power supply voltage, and this must be compatible with the package chosen. This is a close estimate for the dissipation of a circuit: PD= 2 × VS × IS, max + (VS-VO) × VO/RPAR EL4430, EL4431 Output Loading where IS, max is the maximum supply current VS is the ± supply voltage (assumed equal) VO is the output voltage RPAR is the parallel of all resistors loading the output For instance, the EL4431 draws a maximum of 16mA and we might require a 2V peak output into 150Ω and a 270Ω + 270Ω feedback divider. The RPAR is 117Ω. The dissipation with ±5V supplies is 201mW. The maximum supply voltage that the device can run on for a given PD and the other parameter is: VS, max = (PD + VO2/RPAR)/(2IS + VO/RPAR) The maximum dissipation a package can offer is: PD, max = (TJ, max - TA max)/θJA where TJ, max is the maximum die junction temperature, 150°C for reliability, less to retain optimum electrical performance. TA, max is the ambient temperature, 70°C for commercial and 85°C for industrial range. θJA is the thermal resistance of the mounted package, obtained from datasheet dissipation curves. The more difficult case is the SO-8 package. With a maximum die temperature of 150°C and a maximum ambient temperature of 85°C, the 65°C temperature rise and package thermal resistance of 170°C/W gives a dissipation of 382mW at 85°C. This allows a maximum supply voltage of ±8.5V for the EL4431 operated in our example. If an EL4430 were driving a light load (RPAR→∞), it could operate on ±15V supplies at a 70°C maximum ambient. 8 The output stage of the instrumentation amplifiers is very powerful. It typically can source 80mA and sink 120mA. Of course, this is too much current to sustain and the part will eventually be destroyed by excessive dissipation or by metal traces on the die opening. The metal traces are completely reliable while delivering the 30mA continuous output given in the Absolute Maximum Ratings table in this datasheet, or higher purely transient currents. Gain or gain accuracy degrades only 10% from no load to 100Ω load. Heavy resistive loading will degrade frequency response and video distortion for loads <100Ω. Capacitive loads will cause peaking in the frequency response. If capacitive loads must be driven, a small-valued series resistor can be used to isolate it (12Ω to 51Ω should suffice). A 22Ω series resistor will limit peaking to 2.5dB with even a 220pF load. EL4430, EL4431 EL4430,EL4431 Macromodel *Macromodel *This is a Pspice-compatible macromodel of the EL4430 video instrumentation amplifier assembled *as a sub circuit. The pins are numbered sequentially as the subcircuit interface nodes. T1 is a *transmission line which provides a good emulation of the more complicated real device. This model *correctly displays the characteristics of input clipping, frequency response, CMRR both AC and DC, *output clipping, output sensitivity to capacitive loads, gain accuracy, slewrate limiting, input bias *current and impedance. The macromodel does not exhibit proper results with respect to supply current, *supply sensitivities, offsets, output current limit, differential gain or phase, nor temperature. *Connections: IN+ | VIN| | V| | | V+ | | | | VFB | | | | | VREF | | | | | | VOUT | | | | | | | GND | | | | | | | | .SUBCKT EL4430/EL 3 4 2 7 6 5 8 1 *** ***EL4430macromodel*** *** i1710.00103 i2711.00103 i3712.00105 i4713.00105 v17143 v27153 v31923 ****** c1111.03p c2121.03p c31812.1p c416170.6p ****** r110112000 r212132000 r310130e6 r41621000 r51721000 r61811.27e6 r7232120 r8218100 ****** 1121850n ****** d11114diode d21214diode d31815diode d41918diode .modeldioded(tt=120n) ****** q1163101pnp q2174111pnp q3165121pnp q4176131pnp .modelpnppnp(bf=90va=44tr=50n) ****** g11811716.0005 9 EL4430, EL4431 e12011181.0 t1221201z0=50td=1.5n r1t122150 e22312211.0 ****** .ENDS 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 10