P r o d u c t I n n o v a t i o n F r o m

SA12

SA12U

1

SA12

FEATURE

• HIGHFREQUENCYSWITCHING—200kHz

• WIDESUPPLYRANGE—16-200V

• 15ACONTINUOUSTO65°CCASE

• 3PROTECTIONCIRCUITS

• ANALOGORDIGITALINPUTS

• SYNCHRONIZEDOREXTERNALOSCILLATOR

• FLEXIBLEFREQUENCYCONTROL

APPLICATIONS

•REACTIVELOADS

• LOWFREQUENCYSONAR

• LARGEPIEZOELEMENTS

• OFF-LINEDRIVERS

• C-DWELDCONTROLLER

DESCRIPTION

The SA12 is a pulse width modulation amplifier that can

supply 3000W to the load. An internal 400kHz oscillator re-

quires no external components. The clock input stage divides

the oscillator frequency by two, which provides the 200 kHz

switching frequency. External oscillators may also be used to

lower the switching frequency or to synchronize multiple ampli-

fiers. Current sensing is provided for each half of the H-bridge

giving amplitude and direction data. A shutdown input turns

off all four drivers of the H-bridge output. A high side current

limit and the programmable low side current limit protect the

amplifier from shorts to supply or ground in addition to load

shorts. The H-bridge output MOSFETs are protected from

thermal overloads by directly sensing the temperature of the

die. The 12-pin hermetic MO-127 power package occupies

only 3 square inches of board space.

BLOCKDIAGRAMANDTYPICALAPPLICATION

TORQUEMOTORDRIVER

EXTERNALCONNECTIONS

TOP

VIEW

CLK IN

CLK OUT

+PWM

-PWM/RAMP

GND

ILIM/SHDN

ISENSE A

A OUT

+VS

VCC

*

*

B OUT

I SENSE B

1

2

3

4

5

6

12

11

10

9

8

7

TOP

VIEW

Case tied to pin 5. Allow no current in case. Bypassing of supplies

is required. Package is Apex MO-127 (STD). See Outline

Dimensions/Packages in Apex data book.

*See text. As +PWM goes more positive, A OUT duty cycle

increases.

+VS

A OUT

B OUT

ILIM/SHDN

I SENSE A

I SENSE B

RSENSE

RSENSE

MOTOR

GND

CLK IN

CONTROL

SIGNAL

CLK OUT

–PWM/RAMP

+PWM

Vcc

5V

SHUTDOWN

CONTROL

OUTPUT

DRIVERS

PWM

28K

1K

1K

5K

.01μF

100pF

÷2

OSC

CURRENT

LIMIT

9

8

3

10

4

2

1

5

11

12

6

7

5V

12-PINPOWERDIP

PACKAGESTYLECR

Pulse Width Modulation Amplifiers

SA12

P r o d u c t I n n o v a t i o n F r o m

Copyright © Cirrus Logic, Inc. 2009

(All Rights Reserved)

http://www.cirrus.com

MAY2009

APEX−SA12UREVH