Epson Stylus COLOR 3000, Service Manual, Page: 61 / 180

Operating Principles
Rev. A
2-20
2.3.2.3 Motor Driver Circuits
The gate array E05B45 produces the phase data (CRDA0-5) for the CR motor and sends it to 2-channel
D/A converter in parallel data. When the phase-change trigger signal (CRTRG) is sent from the
to the
gate array, the A/B phase-change signal (CRDASEL) is output. Then the A-phase-data and B-phase-data
are transferred to the channel A and channel B in the D/A converter, respectively. The transferred data for
2 phases are converted into analog data in the converter to be transferred to the CR motor driver ICs
(IC19 and IC20), where the phase excitation current is determined for each micro step of the motor. The
minimum micro step 0.013 mm/step is enabled by 4-phase motor with 4W1-2 phase driven. The gate
array E05B45 (IC16) sends phase data (PHASEA/B, ENAN/ENBN) directly to the CR motor driver ICs
A3953 (IC19 and IC20) to control the excitation mode and rotational direction and amount of the motor.
While the CR is in the home position or the printer is in the ink cartridge replacement mode, the 2-2 phase
is driven in the low current hold mode to hold the motor. Figure 2-18 shows the
motor driver circuit
block diagram.
GA
E05B45
(IC16)
CR Motor
CR A
CR B
PHASEA
ENABLE OUTA
OUTB
REF
PHASEB
ENABLE OUTA
OUTB
REF
RFBA
OUTA
RFBB
OUTB
WR
A/B
DB0-7
CRV
CRDALD
CRDASEL
CRDA0-5
PHASEA
ENAN
PHASEB
ENBN
CR A
CR B
CR Motor Driver ICs
A3953 (IC19,20)
D/A Converter
(IC25)
CRTRG CPU
Figure 2-18. CR Motor Block Diagram