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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
* 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

FIGURE 1: BIDIRECTIONAL SPEED CONTROL FROM A SINGLE SUPPLY.
DESCRIPTION
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.
TYPICAL APPLICATION
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 (TOP VIEWS)
PA74

PA76

APEX MICROTECHNOLOGY CORPORATION * TELEPHONE (520) 690-8600 * FAX (520) 888-3329 * ORDERS (520) 690-8601 * EMAIL prodlit@apexmicrotech.com
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PA74/76 * PA74A/PA76A
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 PA74/76 TYP 1.5 20 100 70 90 70
ABSOLUTE MAXIMUM RATINGS SPECIFICATIONS
5V to 40V SOA 36W 60W VS +VS, -VS-0.5V 150C 300C -65C to 150C -55C to 125C PA74A/PA76A TYP MAX .5 10 * * * * 7 250 *
SPECIFICATIONS
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 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 TEST CONDITIONS2 MIN MAX 10 500 +VS-1.3 * * * * MIN UNITS mV V/C nA V dB dB dB
Full temperature range Full temperature range Full temperature range Full temperature range IOUT = 1A, F = 1kHz RS = 100, f = 1 to 100KHz Full temperature range AV = 40dB VO(P-P) = 28V -VS 60 60 50
89 0.9
100 1.4 13.6
* *
* * *
*
dB MHz kHz A V/s V V V V
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
1.4 |VS| -0.9 |VS| -1.7 |VS| -2.9
3 * * * * |VS| -4.0 40 40 *
* * * * |VS| -3.3 * * * *
30 18
V mA
Meets full range specifications
-25
3.2 1.9 2.4 1.4 30
3.5 2.1 2.6 1.6 85 -25
* * * * *
* * * * * 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 = 25C. 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
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 850C to avoid generating toxic fumes.
APEX MICROTECHNOLOGY CORPORATION * 5980 NORTH SHANNON ROAD * TUCSON, ARIZONA 85741 * USA * APPLICATIONS HOTLINE: 1 (800) 546-2739
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TYPICAL PERFORMANCE GRAPHS
PA74/76 * PA74A/PA76A

APEX MICROTECHNOLOGY CORPORATION * TELEPHONE (520) 690-8600 * FAX (520) 888-3329 * ORDERS (520) 690-8601 * EMAIL prodlit@apexmicrotech.com
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PA74/76 * PA74A/PA76A
GENERAL
Please read Application Note 1 "General Operating Considerations" which covers stability, supplies, heatsinking, mounting, SOA interpretation, and specification interpretation. Visit www. apexmicrotech.com for design tools that help automate tasks such as calculations for stability, internal power dissipation, heatsink selection; Apex's complete Application Notes library; Technical Seminar Workbook; and Evaluation Kits.
OPERATING CONSIDERATIONS
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.
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.
SUPPLY CURRENT
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 Supply Current 18mA 20mA 32mA 50mA 75mA

SATURATION OPERATION
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.

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 an Apex TW03 thermal washer, RCS = .1 to .2C/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.
This data sheet has been carefully checked and is believed to be NORTH SHANNON ROAD * TUCSON, ARIZONA 85741 * USA * APPLICATIONS HOTLINE: 1 (800) 546-2739 APEX MICROTECHNOLOGY CORPORATION * 5980 reliable, however, no responsibility is assumed for possible inaccuracies or omissions. All specifications are subject to change without notice.
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PA74-76U REV C NOVEMBER 2004 (c) 2004 Apex Microtechnology Corp.

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