BD6220_09 Datasheet, PDF (9/17 Pages) Rohm – H-bridge drivers (18V max.)

BD6220, BD6221, BD6222, BD6225, BD6226, BD6227
Technical Note
 Functional descriptions
1) Operation modes
Table 7 Logic table
FIN
RIN
VREF OUT1 OUT2
Operation
a
L
L
X
Hi-Z* Hi-Z* Stand-by (idling)
b
H
L
VCC
H
L
Forward (OUT1 > OUT2)
c
L
H
VCC
L
H
Reverse (OUT1 < OUT2)
d
H
H
X
L
L
Brake (stop)
e PWM
L
VCC
H
__________
PWM
Forward (PWM control mode A)
f
L
PWM
VCC
__________
PWM
H
Reverse (PWM control mode A)
g
H
PWM
VCC
__________
PWM
L
Forward (PWM control mode B)
h PWM
H
VCC
L
__________
PWM
Reverse (PWM control mode B)
i
H
L
Option
H
__________
PWM
Forward (VREF control)
j
L
H
Option
__________
PWM
H
Reverse (VREF control)
* Hi-Z is the off state of all output transistors. 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 of 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. If the motor is running at the switch to
stand-by mode, 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. For
operation in this mode, connect the VREF pin with 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. For
operation in this mode, connect the VREF pin with 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 the stand-by mode (rather than
the brake mode) to save power and reduce consumption.
OFF
OFF ON
OFF OFF
ON OFF
OFF
M
M
M
M
OFF
OFF OFF
ON ON
OFF ON
ON
a) Stand-by mode
b) Forward mode
c) Reverse mode
Fig.37 Four basic operations (output stage)
d) Brake mode
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2009.08 - Rev.C