Compaq MP1400 Service Manual page 19

SERVICE MANUAL
ASIC
Color Wheel Controller The A8902CLBA is a three-phase brushless dc motor controller/
Martin 2-12
The Display Controller is an Application Specific Integrated
Circuit (ASIC) intended for use in DMD (Digital micro-mirror
device) systems. The ASIC performs a variety of functions, some
of which are controlling the data flow between DPF2A, memory,
and the DMD as well as generating the DMD reset waveform. The
Display Controller is designed to work in conjunction with two
banks of external SDRAM (type 1M*16), an external SR16C and
an external DPF2A ASIC.
driver for use in 5V or 12V hard-disk drives. The three half-
bridge outputs are low on-resistance n-channel DMOS devices
capable of driving up to 1.25A. The A8902CLBA provides
complete, reliable, self-contained back-EMF sensing motor
startup and running algorithms. A programmable digital frequency-
locked loop speed control circuit together with the linear current
control circuitry provides precise motor speed regulation.