FEATURES
• LOW COST
• WIDE COMMON MODE RANGE —
• WIDE SUPPLY VOLTAGE RANGE
• HIGH EFFICIENCY — |Vs–2.2V| at 2.5A typ
• HIGH OUTPUT CURRENT — 3A min (PA21A)
• INTERNAL CURRENT LIMIT
• LOW DISTORTION
APPLICATIONS
• HALF & FULL BRIDGE MOTOR DRIVERS
• AUDIO POWER AMPLIFIER
• IDEAL FOR SINGLE SUPPLY SYSTEMS
DESCRIPTION
in a 8-pin hermetic TO-3 package (PA21 and PA25) and a 12-
pin SIP package (PA26). Putting two power op amps in one
package and on one die results in an extremely cost effective
solution for applications requiring multiple amplifiers per
board or bridge mode configurations.
rail, facilitating single supply applications. It is possible to
have a “ground based” input driving a single supply amplifier
with ground acting as the “second” or “bottom” supply of the
amplifier.
internal current limit circuits. While the device is well pro-
tected, the Safe Operating Area (SOA) curve must be ob-
served. Proper heatsinking is required for maximum reliabil-
ity.
resistors, ceramic capacitors and semiconductor chips to
maximize reliability, minimize size and give top performance.
Ultrasonically bonded aluminum wires provide reliable inter-
connections 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.
The tab of the SIP12 plastic package is tied to –V
TYPICAL APPLICATION
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.
M I C R O T E C H N O L O G Y
APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL prodlit@apexmicrotech.com
The amplifiers consist of a monolithic dual power op amp
The wide common mode input range includes the negative
The output stages are also well protected. They possess
This hybrid integrated circuit utilizes thick film (cermet)
R1 and R2 set up amplifier A in a non-inverting gain of 2.8.
Includes negative supply
Single supply: 5V to 40V
Split supplies: 2.5V to 20V
STEREO — 18W RMS per channel
BRIDGE — 36W RMS per package
5V — Peripherals
12V — Automotive
28V — Avionic
H T T P : / / W W W . A P E X M I C R O T E C H . C O M
PA21/25/26 • PA21A/25A
POWER DUAL OPERATIONAL AMPLIFIERS
S
.
FIGURE 1: BIDIRECTIONAL SPEED CONTROL FROM
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 0V to 10V 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.
EXTERNAL CONNECTIONS
PA26
3 and 10 to pin 7
and connect pins
4 and 9 to pin 6
unless special
functions are re-
quired.
PA25
OUT, A
–IN, A
The amplifiers are especially well-suited for this application.
Connect pins
+IN, A
4
COMMAND
R1
5
5K
–V
INPUT
0/10V
S
TOP VIEW
3
( 8 0 0 ) 5 4 6 - A P E X
6
– +
A
A SINGLE SUPPLY
+IN, B
+V
–
+
R2
2
9K
A
S
+
7
+28V
1/2 PA21
1
B
–
2
OUT, B
1
+
–IN, B
–
8
3
A
4
M
5
( 8 0 0 ) 5 4 6 - 2 7 3 9
PA21
+IN, A
1/2 PA21
6
+IN, B
SUB
–IN, A
7
R3
R4
–IN, B
4
5
10K
10K
8
B
–
+
3
9
6
B
10
+
–
A
B
11
+V
–V
2
7
S
10K
12
S
10K
R6
R5
+28V
OUT, A
OUT, B
1
8