Pf Motor Driver Circuit - Epson Stylus Color 1520 Service Manual

2.3.2.4 PF Motor Driver Circuit

The PF motor for this printer operates the following:
T
Paper loading
T
Paper feeding
T
Pumping
The gate array E05B33 (IC6) outputs the phase drive control signals (PFAPH and PFBPH), phase data
(PFA0/1 and PPFB1/0), and voltage reference data (PFV) to the driver IC UDN2917EB (IC16). The driver IC
then controls the phase current based on the voltage reference data. This sequence enables the micro step
with a minimum of 1/720 inch at 2-2 phase.
E05B33
(IC6)
PFA0
PFA1
PFB0
PFB1
PFAPH
PFBPH
PO0
PO1
PO2
PO3
45
46
47 23
24
48
49
43
50 26
+5V
33
34 44
PFV
35
25
36
Figure 2-23. PF Motor Driver Circuit Block Diagram
UDN2917EB
(IC16)
2
I10
6
1
I11
A
I20
3
I21
A
18
PH1
B
PH2
21
B
VREF1
VREF2
Operating Principles
PF Motor
PF A
PF_A
PF B
PF_B
2-23