BD64550EFV

Technical Note

7/16

www.rohm.com

2010.06 - Rev.A

© 2010 ROHM Co., Ltd. All rights reserved.

●

Serial Port Explanation

WORD_S

○

SWOFF

Set on/off of switching regulator circuit.

0

Switching regulator on

1

Switching regulator off

○

MASK SELECT

Common mask can be provided to 2-phase H-bridge drive noise mask (BLANK time).

0

Independent mask on single-phase/two-phase.

1

Common mask on single-phase/two-phase.

○

BLANK TIME

Current-limit comparator monitors RNF pin voltage to set limit to current, but during the period from switching on to BLANK

TIME, detection becomes invalid in order to avoid wrong detection caused by spike noise that happens at the time of

switching on. See P.8 for details.And during the period from ENABLE signal on to BLANK TIME at switching of PHASE

signal, detection becomes invalid as well.

[1]

[0]

BLANK TIME

Unit

0

0

2.0

µs

0

1

3.0

µs

1

0

4.0

µs

1

1

5.0

µs

○

OFF TIME

Set current decay time.

[2]

[1]

[0]

OFF TIME

Unit

0

0

0

6

µs

0

0

1

8

µs

0

1

0

10

µs

0

1

1

12

µs

1

0

0

14

µs

1

0

1

16

µs

1

1

0

18

µs

1

1

1

20

µs

WORD_D

○

S_ENABLE_1/S_ENABLE_2

Each bridge on/off signal. Output state is as follows.

Output state

0

Open

1

ACTIVE

○

S_PHASE_1/S_PHASE_2

Set the direction of current of each bridge. Output state is as follows.

P

M

0

SINK

SOURCE

1

SOURCE

SINK

○

PWM_MODE_1/PWM_MODE_2

Set current decay mode in bridge1 and 2. (See page 8 for details about each mode.)

0

FAST DECAY

1

SLOW DECAY

(※)Rohm_Reserve

Rohm_Reserve is special mode setting port for inspection at shipment. Especially, if Rohm Reserve [3], [4], [5], [7], [8], [9], [10], [11] is set to H by mistake,

malfunction may be caused. Be sure not to set.