FULL-BRIDGE PWM MOTOR DRIVER

Note the A3953SB (DIP) and the A3953SLB

(SOIC) are electrically identical and share a

common terminal number assignment.

ABSOLUTE MAXIMUM RATINGS

(Continuous) . . . . . . . . . . . . . . ±1.3 A*

Logic/Reference Input Voltage Range,

Package Power Dissipation,

Operating Temperature Range,

-20°C to +85°C

Storage Temperature Range,

-55°C to +150°C

* Output current rating may be limited by duty

cycle, ambient temperature, and heat sinking.

Under any set of conditions, do not exceed the

specified current rating or a junction temperature

of 150°C.

† Fault conditions that produce excessive junction

temperature will activate the device’s thermal

shutdown circuitry. These conditions can be

tolerated but should be avoided.

Designed for bidirectional pulse-width modulated (PWM) current control

of inductive loads, the A3953S— is capable of continuous output currents to

±1.3 A and operating voltages to 50 V. Internal fixed off-time PWM current-

control circuitry can be used to regulate the maximum load current to a desired

value. The peak load current limit is set by the user’s selection of an input

reference voltage and external sensing resistor. The fixed off-time pulse

duration is set by a user- selected external RC timing network. Internal circuit

protection includes thermal shutdown with hysteresis, transient-suppression

diodes, and crossover current protection. Special power-up sequencing is not

required.

With the ENABLE input held low, the PHASE input controls load current

polarity by selecting the appropriate source and sink driver pair. The MODE

input determines whether the PWM current-control circuitry operates in a slow

current-decay mode (only the selected source driver switching) or in a fast

current-decay mode (selected source and sink switching). A user-selectable

blanking window prevents false triggering of the PWM current-control

circuitry. With the ENABLE input held high, all output drivers are disabled.

A sleep mode is provided to reduce power consumption.

When a logic low is applied to the BRAKE input, the braking function is

enabled. This overrides ENABLE and PHASE to turn off both source drivers

and turn on both sink drivers. The brake function can be used to dynamically

brake brush dc motors.

The A3953S— is supplied in a choice of two power packages; a 16-pin

dual-in-line plastic package with copper heat-sink tabs, and a 16-pin plastic

SOIC with copper heat-sink tabs. For both package styles, the power tab is at

ground potential and needs no electrical isolation. Each package type is

available in a lead (Pb) free version (100% matte tin plated leadframe).

FEATURES

■ ±1.3 A Continuous Output Current

■ 50 V Output Voltage Rating

■ 3 V to 5.5 V Logic Supply Voltage

■ Internal PWM Current Control

■ Saturated Sink Drivers (Below 1 A)

■ Fast and Slow Current-Decay Modes

■ Automotive Capable

■ Sleep (Low Current Con-

sumption) Mode

■ Internal Transient-

Suppression Diodes

■ Internal Thermal-

Shutdown Circuitry

■ Crossover-Current and

UVLO Protection

3953

MODE

GROUND

GROUND

LOGIC

SUPPLY

PHASE

GROUND

GROUND

RC

SENSE

LOAD

SUPPLY

Dwg. PP-056

BRAKE

REF

LOAD

SUPPLY

OUTB

OUTA

LOGIC

ENABLE

1

2

3

4

5

6

7

89

10

11

12

13

14

15

16

*Pb-based variants are being phased out of the product line. The variants cited in this

footnote are in production but have been determined to be LAST TIME BUY. This

classification indicates that sale of this device is currently restricted to existing

customer applications. The variants should not be purchased for new design

applications because obsolescence in the near future is probable. Samples are no

longer available. Status change: October 31, 2006. Deadline for receipt of LAST TIME

BUY orders: April 27, 2007. These variants include: A3953SB, A3953SLB, and

A3953SLBTR.

Part Number

Pb-free*

R

θJA

(°C/W)

R

θJT

(°C/W)

Package

Packing

A3953SB-T

Yes

43

6

16-Pin DIP

25 per Tube

A3953SLB-T

Yes

43

6

16-Lead SOIC

47 per Tube

A3953SLBTR-T

Yes

67

6

16-Lead SOIC

1000 per reel