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:

Paper loading

Paper feeding

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
Rev. A
45
46
47
48
49
50
+5V
33
34 PFV
35
36
Figure 2-23. PF Motor Driver Circuit Block Diagram
UDN2917EB
(IC16)
2
I10
1 6
I11
A
23
I20
24
3
I21
A
18
43
PH1
B
26
PH2
21
B
44
VREF1
25
VREF2
Operating Principles
PF Motor
PF A
PF_A
PF B
PF_B
2-23