Cr Motor Driver Circuit; Reset Circuit - Epson Stylus Photo 720 Service Manual

EPSON Stylus Photo 720 / EPSON Stylus Photo EX3

2.2.2.4 CR Motor Driver Circuit

Motor driver IC (IC13) on C301MAIN board drives CR motor.
Stylus Photo 720 / Stylus Photo EX3 uses 4-phase 200-pole hybrid type stepping motor
and performs constant current bi-polar drive.
ASIC (IC2) converts CR motor phase control signal to LB11847 micro step drive form
and outputs to motor driver IC (IC13) LB11847 from port 93, 105. Based on this
signal, IC13 determines the phase mode.
The current value on each phase is determined by ASIC (IC2) and outputs from port 95
- 112 to driver IC (IC13). Motor driver IC generates motor driver waveform based on
these input signals and controls the motor.
E 0 5 B 7 0 * *
( I C 2 )
9 5
C R I A 0
9 6
C R I A 1
9 7
C R I A 2
9 8
C R I A 3
9 9
C R I B 0
1 0 0
C R I B 1
1 0 1
C R I B 2
1 0 2
C R I B 3
9 3
C R P H A A
1 0 5
C R P H A B
9 4
C R E N B A
1 0 4
C R E N B B
1 1 1
D A 0
H D 6 4 F 2 3 2 8 F
( I C 1 )
Figure 2-16. CR Motor Driver Circuit Block Diagram
Operating Principles
L B 1 1 8 4 7
( I C 1 3 )
2 5
I A 1
2 4
I A 2
2 3
I A 3
C N 1 2
2 2
I A 4
1
1 8
7
I B 1
A
O U T A
1 9
6
I B 2
3
2 0 O U T A -
I B 3 A /
2 1
I B 4
2
B
O U T B
2 7
9
P H A S E 1
1 6
4
8
O U T B -
B /
P H A S E 2
2 6
E N B L 1
1 7
E N B L 2
2
V r e f 1
1 3
V r e f 2
Electrical Circuit Operating Principles

2.2.2.5 Reset Circuit

Reset circuits consist of reset/ timer IC (IC5) and peripheral elements. Reset circuits
are attached on the C301MAIN board to monitor the two voltages: +5V for the logic
line and +42V for the drive line. When each circuit detects abnormality on the
corresponding line, it outputs a reset signal to reset CPU (IC1) and ASIC (IC2). This
function is necessary to prevent the printer from operating abnormally. This IC
monitors both +5V and +45 lines but can reset them independently. The reset circuits
outputs reset signal when +5V line becomes 4.3V or lower or +42V line becomes
35.5V or lower.
Reset ICs have built-in timer function, which manages timer control based on lithium
battery.
IC5
RTC-9810SA
+42 VI N
+5V
VD D
B A T1
VB K
GN D
Figure 2-17. Reset Circuit Block Diagram
Main signal lines are explained below;
RST: Reset line
n
CE: Chip enable line
n
VIN: +42V line supervising line
n
VDD: +5V line supervising line
n
VBK: Lithium battery backup voltage line
n
DATA: Timer data line
n
Revision A
IC1
HD64F2328F
/ R ES
81
IC2
E05B570**
10 140
/ VD T
/ N M I
3
128
FR ST
M R ES
2
136
/ R ST
/ R ESET
C E
TC E
TC LK
SC LK
TD A TA
D A TA
op05
48