Drivers; Pf Motor Driver - Citizen CL-S6621 Technical Manual

2-2-4. Drivers

(1) PF motor driver

This is a driving circuit to drive the "SA PF Motor" (stepping motor).
The following illustration shows a simplified circuit.
The "SA PF Motor" is driven by the unipolar constant current chopper method.
The exciting method for the motor is the 1-2 phase method.
The power to the "SA PF Motor" is controlled by U14 (FPGA). When pin P1 (VMTON) is "High"
level, Q27 and Q25 turn ON and +24V is supplied to the "SA PF Motor".
The exciting method is determined by PFMD1 and PFMD2 signals sent from U14 (FPGA) to
U19 (Motor Driver).
The rotational direction of the "SA PF Motor" is determined by PFDIR signal and PFCLK signal
is a clock signal for turning the "SA PF Motor".
The digital-to-analog converter (U7) is used to control the PF motor current. Its output is
controlled by the data sent from U1A (CPU).
Low: Turns on Q25 to supply
power to "SA Motor PF".
U14
FPGA
VMTON
B1_37
P1
R116
12
From
11
U1A CPU
10
U14
FPGA
PFOFF
B1_39
P3
This circuit is not used.
R112
R114
Q27
DTC114EM
From
U14
FPGA
To/From
U1A CPU
U7
D/A Converter
PFMOTCU
AO1
DI
1
R58
AO2
CK
AO3
CSB
AO4
BH2227
+24V
C121
VMT
Q25
U19
NP15P06SLG
Motor Driver
11
VBB
7
PFMD1
M1
PFMD2 8
M2
PFENB
9
M3
PFDIR 16
CW/CCW
10
PFCLK
CLOCK
18
PFFLAG
FLAG
13
REF/SLEEP1
R59
C93
R60
SLA7073MPRT
Q5
DTC114EM
2-31
Operation of Control Parts
J6
2
5
1
1
OUTA1
2
3
OUTA2
3
OUTA1
4
4
OUTA2
22
6
OUTB1
23
OUTB2
20
OUTB1
21
OUTB2
[SA, Main PCB]
SA PF Motor
PF Motor
M
CL-S6621