BA6438S

Motor driver ICs

!Application example

10

9

8

7

6

5

4

2

1

3

23

24

19

11

Hall

Hall

Hall

0.033

µF

Torque control

signal

0.033

µF

0.1

µF

0.1

µF

ATC

Motor direction

control signal

AGC

Short-circuit

detection

TSD

Signal power

supply

A1

A2

REG

Motor power supply

20

22

18

21

Switching

regulator

Oscil-

lator

Output

saturation

detector

OSC

VS

14

13

15

12

16

17

GND

TL

CS

Motor

direction

detection

Ripple

cancellation

Hall amp

Output

saturation

prevention

Motor direction

setting

A3

ED / S

PCH

0.5

Ω

Fig. 8

!Operation notes

The BA6438S has two thermal shutdown circuits (TSD1

and TSD2) to protect the IC. The typical shutdown tem-

peratures are 175

°C for TSD1 and 215°C for TSD 2.

When the TSD1 is activated at an elevated chip tempera-

ture, the output pins (pins 1, 3, and 23) are set to the open

state. TSD1 is functional against excessive power dis-

sipation, output short-circuiting, and other irregularities in

the output current, but does not work against overheating

caused by high internal currents due to externally caused

IC damage or pin-to-pin short-circuiting.

When TSD2 is activated at a higher chip temperature, the

high-and low-side output transistors are turned on, and

the internal resistance between the motor power supply

pin (pin 24) and the output ground pin (pin 2) drops to less

than 3

en by

=

[V]

[Ω]

where

In your application, make sure to connect between the

motor power supply and pin 24 a circuit breaker that