Very fast 900V/µs, 4A Power Amplifier
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Video Power Operational Amplifier FEATURES • VERY FAST SLEW RATE — 900 V/µs • POWER MOS TECHNOLOGY — 4A peak rating • LOW INTERNAL LOSSES — 0.75V at 2A • PROTECTED OUTPUT STAGE — Thermal Shutoff • WIDE SUPPLY RANGE — ±15V TO ±40V • VIDEO DISTRIBUTION AND AMPLIFICATION • HIGH SPEED DEFLECTION CIRCUITS • POWER TRANSDUCERS UP TO 5 MHz • MODULATION OF RF POWER STAGES • POWER LED OR LASER DIODE EXCITATION TYPICAL APPLICATION DESCRIPTION The PA119 is a high voltage, high current operational amplifier optimized to drive a variety of loads from DC through the video frequency range. Excellent input accuracy is achieved with a dual monolithic FET input transistor which is cascoded by two high voltage transistors to provide outstanding common mode characteristics. All internal current and voltage levels are referenced to a zener diode biased on by a current source. As a result, the PA119 exhibits superior DC and AC stability over a wide supply and temperature range. High speed and freedom from second breakdown is assured by a complementary power MOS output stage. For optimum linearity, especially at low levels, the power MOS transistors are biased in a class A/B mode. Thermal shutoff provides full protection against overheating and limits the heatsink requirements to dissipate the internal power losses under normal operating conditions. A built-in current limit of 0.5A can be increased with the addition of two external resistors. Transient inductive load kickback protection is provided by two internal clamping diodes. External phase compensation allows the user maximum flexibility in obtaining the optimum slew rate and gain bandwidth product at all gain settings. A heatsink of proper rating is recommended. This hybrid circuit utilizes thick film (cermet) resistors, ceramic capacitors, and silicon semiconductor chips to maximize reliability, minimize size, and give top performance. Ultrasonically bonded aluminum wires provide reliable interconnections at all operating temperatures. The 8-pin TO-3 package is hermetically sealed and electrically isolated. The use of compressible thermal washers and/or improper mounting torque will void the product warranty. Please see “General Operating Considerations” . TYPICAL APPLICATION –40V PA119 AS FAST POWER DRIVER This fast power driver utilizes the 900V/µs slew rate of the PA119 and provides a unique interface with a current output DAC. By using the DAC’s internal 1KΩ feedback resistor, temperature drift errors are minimized, since the temperature drift coefficients of the internal current source and the internal feedback resistor of the DAC are closely matched. Gain of VOUT to IIN is –6.5/mA. The DAC’s internal 1K resistor together with the external 500Ω and 110Ω form a “tee network” in the feedback path around the PA119. This effective resistance equals 6.5KΩ . Therefore the entire circuit can be modeled as 6.5KΩ feedback resistor from output to inverting input and a 5mA current source into the inverting input of the PA119. Now we see the familiar current to voltage conversion for a DAC where VOUT = –IIN x RFEEDBACK. Copyright © Apex Microtechnology, Inc. 2012 (All Rights Reserved) PHASE COMPENSATION GAIN

PA119CE • PA119CEA ABSOLUTE MAXIMUM RATINGS SUPPLY VOLTAGE, +VS to –VS OUTPUT CURRENT, within SOA POWER DISSIPATION, internal INPUT VOLTAGE, differential INPUT VOLTAGE, common mode TEMPERATURE, pin solder — 10 sec TEMPERATURE, junction1 TEMPERATURE, storage OPERATING TEMPERATURE RANGE, case SPECIFICATIONS PARAMETER INPUT OFFSET VOLTAGE, initial OFFSET VOLTAGE, vs. temperature OFFSET VOLTAGE, vs. supply OFFSET VOLTAGE, vs. power BIAS CURRENT, initial BIAS CURRENT, vs. supply OFFSET CURRENT, initial INPUT IMPEDANCE, DC INPUT CAPACITANCE COMMON MODE VOLTAGE RANGE3 COMMON MODE REJECTION, DC...

SLEW RATE VS. COMP. POWER SUPPLY REJECTION, PSR (dB) COMMOM MODE REJECTION, CMR (dB) COMMON MODE REJECTION PULSE RESPONSE POWER SUPPLY REJECTION POWER RESPONSE OUTPUT VOLTAGE SWING QUIESCENT CURRENT OPEN LOOP GAIN, AOL (dB) VOLTAGE DROP FROM SUPPLY (V) SMALL SIGNAL RESPONSE NORMALIZED QUIESCENT CURRENT, IQ (X) INPUT NOISE VOLTAGE, VN (nV/√Hz) CURRENT LIMIT COMMON MODE VOLTAGE, VCM (VP–P) POWER DERATING CURRENT LIMIT, ILIM (A) INTERNAL POWER DISSIPATION, P(W) INPUT NOISE COMMON MODE VOLTAGE

GENERAL Please read Application Note 1 "General Operating Considerations" which covers stability, supplies, heat sinking, mounting, current limit, SOA interpretation, and specification interpretation. Visit www.apexanalog.com for design tools that help automate tasks such as calculations for stability, internal power dissipation, current limit; heat sink selection; Apex Microtechnology’s complete Application Notes library; Technical Seminar Workbook; and Evaluation Kits. CURRENT LIMIT Q2 (and Q25) limit output current by turning on and removing gate drive when voltage on pin 2 (pin 7)...

The thermal protection circuit shuts off the amplifier when the substrate temperature exceeds approximately 150°C. This allows the heatsink selection to be based on normal operating conditions while protecting the amplifier against excessive junction temperature during temporary fault conditions. Thermal protection is a fairly slow-acting circuit and therefore does not protect the amplifier against transient SOA violations (areas outside of the steady state boundary). It is designed to protect against short-term fault conditions that result in high power dissipation within the amplifier. If...