108&3ꢀ%6"-ꢀ01&3"5*0/"-ꢀ".1-*'*&34
PA74/76 • PA74/76A
M
I C R O T E C H N O L O G Y
)551ꢀꢁꢁ888ꢂ"1&9.*$305&$)ꢂ$0.ꢃꢃꢃꢄꢅꢆꢆꢇꢃꢈꢉꢊꢋ"1&9ꢃꢃꢃꢄꢅꢆꢆꢇꢃꢈꢉꢊꢋꢌꢍꢎꢏ
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
3ꢆ
3ꢃ
ꢄ,
3ꢅ
ꢂꢀ,
ꢂꢀ,
ꢋꢃꢌ7
"
ꢋꢃꢌ7
3ꢂ
ꢇ,
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
@
ꢋ
@
3ꢇ
ꢂꢀ,
#
.
ꢋ
ꢂꢁꢃꢉ1"ꢊꢆ
ꢂꢁꢃꢉ1"ꢊꢆ
3ꢈ
ꢂꢀ,
$0.."/%
*/165
FIGURE 1: BIDIRECTIONAL
SPEED CONTROL FROM A
SINGLE SUPPLY.
ꢀꢁꢂꢀ7
TYPICAL APPLICATION
DESCRIPTION
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.
Theextendedcommonmoderangeallowscommandinputsas
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.
Theamplifierdesignconsistsofdualmonolithicinputandoutput
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
compensatedforstability.ThePA74andPA76dualamplifiersare
designedwithbothmonolithicandhybridtechnologiesproviding
acosteffectivesolutionforapplicationsrequiringmultipleampli-
fiers per board or bridge mode configurations. Both amplifiers
are internally compensated but are not recommended for use
as unity gain followers.
Thisdualhybridcircuitutilizesaberyllia(BeO)substrate,thick
film resistors, ceramic capacitors and monolithic amplifiers to
maximizereliabilityandpowerhandlingcapability,minimizesize
andgivetopperformance.Ultrasonicallybondedaluminumwires
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.
EXTERNAL CONNECTIONS (TOp viEws)
EQUIVALENT SCHEMATIC ONE CHANNEL
PA74ꢀ
ꢀ
ꢀ
ꢈ74
ꢁ
ꢀꢀꢀꢀꢀPA76
ꢀ74
ꢈ74
ꢁ
ꢈ*/ꢉꢊ"
ꢂ
*ꢂ#*"4
.0/*503
065ꢉꢊ"
ꢀ
065ꢉꢊ#
ꢀ
ꢂ
m*/ꢉꢊ"
$633&/5
("*/
m*/ꢉꢊ"
"
#
ꢃ
ꢃ
m
ꢅ
ꢈ
ꢈ*/ꢉꢊ"
ꢁ*/
ꢀ*/
5)&3."-
1305&$5
"
#
065
ꢈ
m
ꢄ
ꢄ
ꢇ
ꢈ*/ꢉꢊ#
ꢇ
065ꢉꢊ"
m74
$633&/5
("*/
065ꢉꢊ#
ꢅ
m*/ꢉꢊ#
ꢆ
m74
m*/ꢉꢊ#
ꢆ
ꢈ*/ꢉꢊ#
ꢁ74
APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL prodlit@apexmicrotech.com
1