Sharp FO-5700 Service Manual page 60

FO-5700U
(11) Driver block
Sending motor driver (IC7: LB1845) ---- 28-pin DIP
This IC driver at the sending motor at the constant current with the bipo-
lar, chopper system.
VCC 28
TSD
–
PHASE1 25
+
VREF1 26
–
ENABLE1 24
+
–
22
I01
+
–
23
I11
+
[Truth Table]
ENABLE PHASE OUTA
L H H
L L L
H – OFF
I I
0 1
L L Vref/ (10 x R
H L Vref/ (15 x R
L H Vref/ (30 x R
H H
Note: When ENABLE = H or I = I
0
6 7 1 14
OUTPUT OUTPUT
BLOCK BLOCK
OUTPUT OUTPUT
BLOCK BLOCK
–
ONE
SHOT
+
3 2 27
OUTB
L
H
OFF
Output Current
) = I
E OUT
) = I x 2/3
E OUT
) = I x 1/3
E OUT
0
= H, the output is in OFF state.
1
8
OUTPUT
BLOCK
OUTPUT
BLOCK
–
ONE
SHOT
+
4 11 15 16 12
Fig. 4
5 – 16
9
OUTPUT
BLOCK
–
OUTPUT
BLOCK
+
–
+
–
+
–
+
13
18 PHASE2
17 VREF2
19 ENABLE2
21 I02
20 I12