1996 May 06

13

Philips Semiconductors

Product specification

12 V Voice Coil Motor (VCM) driver and

spindle motor pre-driver combination chip

TDA5149G

Table 9

REG # 4: address 101; | WATCHDOG_REG[4 to 0] |

Table 10 REG # 6: address 110; | not used | not used | COMDELIM_REG[2 to 0] |

Table 11 Commutation delay limit

Note

1. Even COMDELIM _REG values must be avoided.

Table 12 REG # 7: address 111; | BLANK_REG[4 to 0] |

DATA BIT

RESET

STATE

DESCRIPTION

WATCHDOG_4

0

The watchdog timer checks for correct back EMF polarity, which indicates correct

rotation of the motor

WATCHDOG_3

0

WATCHDOG_2

0

WATCHDOG_1

0

WATCHDOG_0

0

DATA BIT

RESET

STATE

DESCRIPTION

COMDELIM_2

0

Defines the maximum commutation delay limit by setting the saturation value of the

shows the delays which can be obtained.

COMDELIM_1

0

COMDELIM_0

0

COMDELIM_REG

COUNTER SATURATION VALUE

MAXIMUM COMMUTATION DELAY

111

2047

110; note 1

1535

101

1023

100; note 1

767

011

511

010; note 1

383

001

255

000; note 1

191

DATA BIT

RESET

STATE

DESCRIPTION

BLANK_4

0

In the hard switching mode, the blank delay inhibits the back EMF comparator

outputs just at the moment the MOT outputs are commutating, until they have been

stabilized again. To avoid false zero-crossing detection, the blank delay operates in

the same way at the end of the fly-back pulse (hard-switching mode), or at the end

of the soft-switching interval (soft-switching mode).

BLANK_3

0

BLANK_2

0

BLANK_1

0

BLANK_0

0

WATCHDOG delay

0 to 31

{

} 64

×

(

) 1

+

[

] t

IC

×

=

BLANK delay

0 to 31

{

} 4

×

(

) 1

+

[

] t

IC

×

=