Document order number: MC33780
Rev 3.0, 5/2006
Dual DBUS Master with
Differential Drive and
The 33780 is a master device for two differential DBUS buses. It
contains the logic to interface the buses to a standard serial
peripheral interface (SPI) port and the analog circuitry to drive data
and power over the bus as well as receive data from the remote slave
The differential mode of the 33780 generates lower electro-
magnetic interference (EMI) in situations where data rates and wiring
make this a problem. Frequency spreading further reduces in-
terference by spreading the energy across many channels, reducing
the energy in any single channel.
• Two Independent DBUS I/Os
• Common SPI Interface for All Operations
• Open-Drain Interrupt Output with Pull-up
• Maskable Interrupts for Send and Receive Data Status
• Automatic Message Cyclical Redundancy Checking (CRC)
Generation and Checking
• Four-Stage Transmit and Receive Buffers
• 8- to 16-Bit Messages with 0- to 8-Bit CRC
• Independent Frequency Spreading for Each Channel
• Pb-Free Packaging Designated by Suffix Code EG
DIFFERENTIAL DBUS MASTER
EG (Pb-FREE SUFFIX)
MC33780EG/R2 -40°C to 85°C
4.7 nF capacitors from D0H, D0L, D1H
and D1L to circuit ground are required
for proper operation.
Figure 1. 33780 Simplified Application Diagram
* This document contains certain information on a new product.
Specifications and information herein are subject to change without notice.
© Freescale Semiconductor, Inc., 2006. All rights reserved.