Daattaasshheeeett
BD621xxx Series
●Functional Descriptions
1) Operation modes
Table 4 Logic table
FIN
RIN
VREF
X
OUT1
OUT2
Hi-Z*
L
Operation
a
b
c
d
e
f
L
L
Hi-Z*
Stand-by (idling)
H
L
H
VCC
VCC
X
H
L
Forward (OUT1 > OUT2)
Reverse (OUT1 < OUT2)
Brake (stop)
L
H
H
H
L
L
__________
PWM
L
L
VCC
VCC
VCC
VCC
Option
Option
H
Forward (PWM control mode A)
Reverse (PWM control mode A)
Forward (PWM control mode B)
Reverse (PWM control mode B)
Forward (VREF control)
PWM
__________
PWM
__________
PWM
PWM
PWM
H
H
L
__________
PWM
__________
PWM
g
h
i
H
PWM
H
L
L
H
__________
j
L
H
H
Reverse (VREF control)
PWM
* Hi-Z i: all output transistors are off. Please note that this is the state of the connected diodes, which differs from that of the mechanical relay.
X : Don’t care
a) Stand-by mode
Stand-by operates independently with the VREF pin voltage. In stand-by mode, all internal circuits are turned off,
including the output power transistors. Motor output goes to high impedance. When the system is switched to
stand-by mode while the motor is running, the system enters an idling state because of the body diodes. However,
when the system switches to stand-by from any other mode (except the brake mode), the control logic remains in
the high state for at least 50µs before shutting down all circuits.
b) Forward mode
This operating mode is defined as the forward rotation of the motor when the OUT1 pin is high and OUT2 pin is low.
When the motor is connected between the OUT1 and OUT2 pins, the current flows from OUT1 to OUT2. To operate
in this mode, connect the VREF pin to the VCC pin.
c) Reverse mode
This operating mode is defined as the reverse rotation of the motor when the OUT1 pin is low and OUT2 pin is high.
When the motor is connected between the OUT1 and OUT2 pins, the current flows from OUT2 to OUT1. To operate
in this mode, connect the VREF pin to the VCC pin.
d) Brake mode
This operating mode is used to quickly stop the motor (short circuit brake). It differs from the stand-by mode
because the internal control circuit is operating in the brake mode. Please switch to stand-by mode (rather than the
brake mode) to save power and reduce consumption.
OFF
OFF
OFF ON
OFF OFF
OFF OFF
ON OFF
OFF ON
OFF
ON
M
M
M
M
ON
ON
a) Stand-by mode
b) Forward mode
c) Reverse mode
d) Brake mode
Fig.30 Four basic operations (output stage)
www.rohm.com
TSZ02201-0P2P0B300070-1-2
25.Dec.2012 Rev.002
© 2012 ROHM Co., Ltd. All rights reserved.
10/18
TSZ22111･15･001
ROHM [ ROHM ]
