33889 datasheet(35/60 Pages) FREESCALE

Part #	33889

Description	System Basis Chip with Low Speed Fault Tolerant CAN Interface

PDF	60 Pages

Scroll/Zoom	100%

Manufacturer	FREESCALE [Freescale Semiconductor, Inc]

Direct Link	http://www.freescale.com

Logo

35 / 60 page

Analog Integrated Circuit Device Data

Freescale Semiconductor

33889

FUNCTIONAL DEVICE OPERATION

OPERATIONAL MODES

Figure 15. Bus State Report of the CAN Interface Wake-Up Comparator on CANL and CANH

CANL

CANH

Dominant

Recessive

state

CANL terminated to Vbat

Dominant

Recessive

state

Other CAN node send

TWAKE

CAN in TxRx

MC33889D in Normal mode

CAN in TermVbat

MC33889D in Normal mode, Standby mode or in stop mode

CAN in TxRx

MC33889D in Normal mode

Dominant state

TWAKE

Tx sender node

Rx MC33889D

TRX_DOM

TBUS_DOM

TWAKE: duration of the CAN wake up filter, typ 16µs. The MC33889D Rx dominant low level duration is the difference

between the duration of the bus minus the Twake, as illustrated below (Trx_dom = Tbus_dom - Twake)

Example: A dominant duration at the bus level of 5

bits of 8us each results in a 40us bus dominant.

This results in a 24

µs (40µs-16µs) dominant level at

Rx of MC33889D (while the CAN of the MC33889D

is in TermVbat).

Tx MC33889D

33889 Datasheet(PDF) 35 Page - Freescale Semiconductor, Inc