1999 March 15

11

Philips Semiconductors

Product specification

Brushless DC motor drive circuit

TDF5140A

Fig.5 Typical application of the TDF5140A as a scanner driver, with use of OTA.

handbook, full pagewidth

MBK986

START-UP

OSCILLATOR

1

15

4

18

3

ADAPTIVE

COMMUTATION

DELAY

COMMUTATION

LOGIC

TIMING

THERMAL

PROTECTION

ROTATION

SPEED/

DETECTOR

OUTPUT

STAGE

DIVIDE

BY 2

POSITION

DETECTOR

STAGE

16

EMF COMPARATORS

17

75

8

GND2

GND1

VP

6

FG to

micro-

processor

12

2

TEST

9

10

11

14

13

TDF5140A

D

D

TP

TN

TN

D

D

TP

TN

TN

D

D

TP

TN

TN

SCANNER

MOTOR

POSITION

COIL

10 nF

4.7

k

Ω

+5 V

18 nF

18 nF

220 nF

from

DAC

1

µF

120

Ω

39 k

Ω

47 k

Ω

10 k

Ω

470

Ω

680

Ω

47 nF

BD434

47 nF

+14 V