PA76

PA74/PA76 • PA74A/76A PA74/76 • PA74A/76A PA74, PA76, PA74A, PA76A Power Dual Operational Amplifiers FEATURES • LOW COST • WIDE COMMON MODE RANGE — Includes negative supply • WIDE SUPPLY VOLTAGE RANGE Single supply: 5V to 40V Split supplies: ±2.5V to ±20V • HIGH EFFICIENCY — |Vs–2.2V| at 2.5A typ • HIGH OUTPUT CURRENT — 3A • LOW DISTORTION 8-PIN TO-3 PACKAGE STYLE CE APPLICATIONS R2 +28V 9K R1 5K • HALF & FULL BRIDGE MOTOR DRIVERS • AUDIO POWER AMPLIFIER STEREO — 30W RMS per channel BRIDGE — 60W RMS per package • IDEAL FOR SINGLE SUPPLY SYSTEMS 5V — Peripherals, 12V — Automotive 28V — Avionic R4 10K R3 10K +28V _ _ M A + COMMAND INPUT 0/10V B 1/2 PA74 R5 10K + 1/2 PA74 R6 10K FIGURE 1: BIDIRECTIONAL SPEED CONTROL FROM A SINGLE SUPPLY. DESCRIPTION TYPICAL APPLICATION The amplifier design consists of dual monolithic input and output stages to achieve the desired input and output characteristics of the PA74 and PA76. The input stage utilizes a dual power op amp on a single chip monolithic that drives the output stages. The output stages are configured in a non inverting unity gain buffer configuration. The output stages of the amplifier are also compensated for stability. The PA74 and PA76 dual amplifiers are designed with both monolithic and hybrid technologies providing a cost effective solution for applications requiring multiple amplifiers per board or bridge mode configurations. Both amplifiers are internally compensated but are not recommended for use as unity gain followers. This dual hybrid circuit utilizes a beryllia (BeO) substrate, thick film resistors, ceramic capacitors and monolithic amplifiers to maximize reliability and power handling capability, 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 isolation washers voids the warranty. R1 and R2 set up amplifier A in a non-inverting gain of 2.8. Amp B is set up as a unity gain inverter driven from the output of amp A. Note that amp B inverts signals about the reference node, which is set at mid-supply (14V) by R5 and R6. When the command input is 5V, the output of amp A is 14V. Since this is equal to the reference node voltage, the output of amp B is also 14V, resulting in 0V across the motor. Inputs more positive than 5V result in motor current flow from left to right (see Figure 1). Inputs less positive than 5V drive the motor in the opposite direction. The amplifiers are especially well-suited for this application. The extended common mode range allows command inputs as low as 0V. Its superior output swing abilities let it drive within 2V of supply at an output current of 2A. This means that a command input that ranges from 0.714V to 9.286V will drive a 24V motor from full scale CCW to full scale CW at up to ±2A. A single power op amp with an output swing capability of Vs –6 would require ±30V supplies and would be required to swing 48V p-p at twice the speed to deliver an equivalent drive. EQUIVALENT SCHEMATIC ONE CHANNEL EXTERNAL CONNECTIONS PA74 I BIAS MONITOR OUT,B CURRENT GAIN -IN PA76 -VS +VS +IN THERMAL PROTECT 8 OUT CURRENT GAIN B TOP VIEW A 1 OUT,A -VS www.apexanalog.com PA74-76U +VS +IN,B –IN,B 7 6 – + 4 – Copyright © Apex Microtechnology, Inc. 2012 (All Rights Reserved) 3 -IN,A +IN,A 6 8 5 + 2 +IN,B –VS 7 -IN,B TOP VIEW – B + + 1 OUT,B +VS 2 OUT,A 5 A – 3 4 -IN,A +IN,A OCT 2012 1 PA74-76U REVH PA74/76 • PA74A/76A ABSOLUTE MAXIMUM RATINGS SUPPLY VOLTAGE, total OUTPUT CURRENT POWER DISSIPATION, internal (per amplifier) POWER DISSIPATION, internal (both amplifiers) INPUT VOLTAGE, differential INPUT VOLTAGE, common mode JUNCTION TEMPERATURE, max1 TEMPERATURE, pin solder–10 sec max TEMPERATURE RANGE, storage OPERATING TEMPERATURE RANGE, case 5V to 40V SOA 36W 60W ±VS +VS, -VS–0.5V 150°C 350°C –65°C to 150°C –55°C to 125°C SPECIFICATIONS TEST CONDITIONS2 PARAMETER INPUT OFFSET VOLTAGE, initial OFFSET VOLTAGE, vs. temperature BIAS CURRENT, initial COMMON MODE RANGE COMMON MODE REJECTION, DC POWER SUPPLY REJECTION CHANNEL SEPARATION INPUT NOISE VOLTAGE GAIN OPEN LOOP GAIN GAIN BANDWIDTH PRODUCT POWER BANDWIDTH OUTPUT CURRENT, peak SLEW RATE VOLTAGE SWING VOLTAGE SWING VOLTAGE SWING VOLTAGE SWING MIN Full temperature range Full temperature range Full temperature range Full temperature range IOUT = 1A, F = 1kHz RS = 100Ω, f = 1 to 100KHz –VS 60 60 50 Full temperature range AV = 40dB VO(P-P) = 28V 89 0.9 Full temp. range, IO = 100mA Full temp. range, IO = 1A IO = 2.5A (PA74, 76) IO = 3.0A (PA74A, PA76A) 2.5 0.5 |VS| –1.1 |VS| –2.0 |VS| –3.5 POWER SUPPLY VOLTAGE, VSS3 CURRENT, quiescent, total THERMAL RESISTANCE, junction to case DC, single amplifier DC, both amplifiers4 AC, single amplifier AC, both amplifiers4 RESISTANCE, junction to air TEMPERATURE RANGE, case Meets full range specifications –25 PA74/76 TYP 1.5 20 100 70 90 70 100 1.4 13.6 1.4 |VS| –0.9 |VS| –1.7 |VS| –2.9 PA74A/PA76A MAX MIN TYP MAX UNITS 10 .5 7 10 500 * 250 +VS–1.3 * * * * * * * * mV µV/°C nA V dB dB dB * * * * * * dB MHz kHz 3 * * * * * * * * |VS| –4.0 |VS| –3.3 A V/µs V V V V 30 18 40 * 40 * * 3.2 1.9 2.4 1.4 30 3.5 * 2.1 * 2.6 * 1.6 * * 85 –25 * * V mA * * * * * 85 °C/W °C/W °C/W °C/W °C/W °C NOTES: * The specification of PA74A/PA76A is identical to the specification for PA74/PA76 in applicable column to the left. 1. Long term operation at the maximum junction temperature will result in reduced product life. Derate internal power dissipation to achieve high MTTF. 2. Unless otherwise noted, the following conditions apply: ±VS = ±15V, TC = 25°C. 3. +VS and –VS denote the positive and negative supply rail respectively. VSS denotes the total rail-to-rail supply voltage. 4. Rating applies when power dissipation is equal in the two amplifiers. CAUTION 2 The internal substrate contains beryllia (BeO). Do not break the seal. If accidentally broken, do not crush, machine, or subject to temperatures in excess of 850°C to avoid generating toxic fumes. PA74-76U 1.4 1.2 1.0 0.8 0.6 0.4 -80 -20 20 60 100 140 CASE TEMPERATURE, TC (°C) PULSE RESPONSE OUTPUT VOLTAGE, VO (V) 15 5 0 80 60 70 0.7 0.6 0.5 0.4 0 5 10 15 SUPPLY VOLTAGE, VS (V) 20 PULSE RESPONSE 10 5 0 +VS = +15V AV = +1 VIN = 10Vp -VS = -15V -10 RL = 10Ω f = 1KHz -15 IN 0 200 400 600 800 1.0K 1.2K 1.4K TIME, t (s) -5 60 GAIN, A (dB) PHASE, Ф (°) 0.8 80 120 160 200 240 PA74-76U 0.9 VOLTAGE GAIN vs. FREQUENCY PHASE vs. FREQUENCY 280 1K 1.0 15 10 +VS = +15V AV = +1 -5 VIN = 10Vp -V = -15V -10 R S= 10Ω L fIN = 20KHz -15 0 10 20 30 40 50 TIME, t (s) 1.1 40 20 0 -20 10K 100K 1M FREQUENCY, f (Hz) 10M -40 1K 10K 100K 1M FREQUENCY, f (Hz) 10M VOLTAGE DROP FROM SUPPLY, VDROP (V) 1.5 1.2 4.0 OUTPUT VOLTAGE SWING 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 OUTPUT CURRENT, IO (A) NORMALIZED BIAS CURRENT, IB (X) 1.8 NORMALIZED QUIESCENT CURRENT vs. SUPPLY VOTAGE 1.3 NORMALIZED OFFSET VOLTAGE, VOS (X) 2.0 OUTPUT VOLTAGE, VO (V) NORMALIZED QUIESCENT CURRENT, IQ (X) NORMALIZED QUIESCENT CURRENT vs. CASE TEMPERATURE NORMALIZED QUIESCENT CURRENT, IQ (X) PA74/76 • PA74A/76A 8 IB 1.2 1.1 1.0 0.9 0.8 0.7 0.6 -80 -40 0 40 80 120 160 TEMPERATURE, (°C) VOS 4 0 -4 -40 0 40 80 120 TEMPERATURE, (°C) 3 PA74/76 • PA74A/76A GENERAL Please read Application Note 1 "General Operating Considerations" which covers stability, supplies, heatsinking, mounting, SOA interpretation, and specification interpretation. Visit www. apexanalog.com for design tools that help automate tasks such as calculations for stability, internal power dissipation, heatsink selection; Apex Microtechnology's complete Application Notes library; Technical Seminar Workbook; and Evaluation Kits. PARALLEL CONFIGURATION CONSIDERATIONS LOSSES The PA74 and PA76 utilize a parallel configuration to achieve the desired current output requirements.The parallel configuration inherently creates internal losses due to circulating currents. The circulating currents generate power losses through the current sharing resistors when delivering current to the load. SUPPLY CURRENT STABILITY CONSIDERATIONS All monolithic power op amps use output stage topologies that present special stability problems. This is primarily due to non-complementary (both devices are NPN) output stages with a mismatch in gain and phase response for different polarities of output current. It is difficult for the opamp manufacturer to optimize compensation for all operating conditions. The parallel configuration used in the PA74 and PA76 also generates supply currents while high voltage sign waves are seen at the output. Listed below are the supply currents expected while running at a particular frequency and when VO ≈ 15Vpp, note that the outputs are not loaded. Frequency 100Hz 1KHz 5KHz 10KHz 15KHz TWO AMPLIFIERS LOADED DC, TC = 25°C SATURATION OPERATION ONE AMPLIFIER LOADED The parallel configuration used in the PA74 and PA76 is sensitive to operation in the saturation region. The PA74 and PA76 may exhibit large peak currents; this is mainly due to thermal protection limitations. 1.0 DC, TC = 85°C 0.1 1.0 10 100 SUPPLY TO OUTPUT DIFFERENTIAL VOLTAGE, VS - VO (V) SAFE OPERATING AREA (SOA) The SOA curves combine the effect of all limits for this power op amp. For a given application, the direction and magnitude of the output current should be calculated or measured and checked against the SOA curves. This is simple for resistive loads but more complex for reactive and EMF generating loads. THERMAL CONSIDERATIONS Thermal grease or a Apex Microtechnology TW03 thermal washer, RCS = .1 to .2°C/W, is the only recommended interface for the PA74/76. Internal power dissipation increases directly with frequency therefore it is critical to sufficiently heat sink the PA74 and PA76. Even unloaded the PA74 and PA76 can dissipate up to 3 watts while running at higher frequencies. 4 INTERNAL POWER DISSIPATION, P (W) OUTPUT CURRENT FROM +VS or -VS, (A) SOA 10 Supply Current 18mA 20mA 32mA 50mA 75mA POWER DERATING 70 TWO AMPLIFIERS LOADED 60 50 40 ONE AMPLIFIER LOADED 30 20 10 0 0 25 50 75 100 CASE TEMPERATURE, TC (°C) 125 PA74-76U PA74/76 • PA74A/76A NEED TECHNICAL HELP? CONTACT APEX SUPPORT! For all Apex Microtechnology product questions and inquiries, call toll free 800-546-2739 in North America. For inquiries via email, please contact apex.support@apexanalog.com. International customers can also request support by contacting their local Apex Microtechnology Sales Representative. To find the one nearest to you, go to www.apexanalog.com IMPORTANT NOTICE Apex Microtechnology, Inc. has made every effort to insure the accuracy of the content contained in this document. However, the information is subject to change without notice and is provided "AS IS" without warranty of any kind (expressed or implied). Apex Microtechnology reserves the right to make changes without further notice to any specifications or products mentioned herein to improve reliability. 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PRODUCTS IN SUCH APPLICATIONS ARE UNDERSTOOD TO BE FULLY AT THE CUSTOMER OR THE CUSTOMER’S RISK. Apex Microtechnology, Apex and Apex Precision Power are trademarks of Apex Microtechnolgy, Inc. All other corporate names noted herein may be trademarks of their respective holders. PA74-76U www.apexanalog.com Copyright © Apex Microtechnology, Inc. 2012 (All Rights Reserved) OCT 2012 5 PA74-76U REVH