Rainbow Electronics BA6285FP - Manual (Page 6)

428
Motor driver ICs BA6285FS / BA6285FP
F
Circuit operation
(1) Input section
The four output modes are controlled by two logic inputs.
Current flows from OUT1 to OUT2 when F
IN
is HIGH and
R
IN
is LOW, and from OUT2 to OUT1 when R
IN
is HIGH
and F
IN
is LOW (refer to the truth table). The input circuit
can be operated by a logic circuit with a current capacity
of 120
X 170
µ
A.
(2) Output section
Current flows from OUT1 to OUT2 during forward rota-
tion, and from OUT2 to OUT1 during reverse rotation.
The output voltages V
OH
and V
OL
are given by :
V
OH
[V]=V
REF
– V
CE (sat)
(PNP) – V
BE
(NPN)
V
OL
[V]=V
CE (sat)
(NPN)
V
CE
and V
BE
are functions of the output current (see elec-
trical characteristic curves). The output current can be
set with the V
REF
pin.
(3) Power saving circuit
All circuits are turned OFF when the F
IN
and R
IN
input pins
are both LOW or the POWER SAVE pin is HIGH. This cir-
cuit saves power during standby mode by leaving the
outputs OPEN.