33790 Datasheet, PDF (9/12 Pages) Freescale Semiconductor, Inc – Two-Channel Distributed System Interface (DSI) Physical Interface Device

TYPICAL APPLICATIONS
FUNCTIONAL TERMINAL DESCRIPTION
TYPICAL APPLICATIONS
The 33790 is intended for use in a DSI system. This device
supplies the interface between standard logic levels and the
voltage and current required for the DSI bus. Two
independent DSI busses are supported by this part. The
33790 does not form the timing for the DSI bus. This is done
by logic either embedded in a microcontroller or by the
MC68HC55, which uses SPI commands and forms DSI
protocol for communications over the DSI bus.
The pins from the MC68HC55 are made to line up with the
pins connecting to the 33790. This includes all the DSIxF,
DSIxS, and DSIxR pins.
A capacitor attached to CPCAP serves as a charge
reservoir for the gate drive charge pump. This circuit creates
a voltage that is higher than the source of the N-channel
output transistor. This allows turning on of the transistor
enough to prevent any significant voltage drop across it. The
rest of charge pump electronics are completely self-
contained on the IC.
Analog Integrated Circuit Device Data
Freescale Semiconductor
33790
9