Epson L-1000 Technical Manual page 178

REV.-A
APPENDIX
A.1.5 STK6981 B (7C)
The STK6981 B is a two-circuit, 4-phase stepper motor driver for unipolar constant-current driving. The chopping
operation is performed to improve the start-up characteristics and minimize heat generation with the constant
current.
The holding terminal included in the STK6981B controls temporary holding
Figure A-13. STK6981 B Functional Equivalent Circuit
LQ-500/ L-1000
A-13