NCV7356(2004) View Datasheet(PDF) - ON Semiconductor

Part Name

Description

Manufacturer

NCV7356
(Rev.:2004)

Single Wire CAN Transceiver

ON Semiconductor 

NCV7356

RxD Output Pin

Logic data as sensed on the single wire CAN bus.

RxD Polarity

• RxD = logic 1 on this pin indicates a bus recessive

state (low bus voltage)

• RxD = logic 0 on this pin indicates a bus normal or

high voltage bus dominant state

RxD in Sleep Mode

RxD does not pass signals to the microprocessor while in

sleep mode until a valid wake−up bus voltage level is

received or the MODE0 and MODE 1 pins are not 0, 0

respectively. When the valid wake−up bus voltage signal

awakens the transceiver, the RxD pin signals an interrupt

(logic 0). If there is no mode change within 250 ms (typ),

the transceiver re−enters the sleep mode.

When not in sleep mode all valid bus signals will be sent

out on the RxD pin.

RxD will be placed in the undriven or off state when in

sleep mode.

RxD Typical Load

Resistance: 2.7 kW

Capacitance: < 25 pF

Bus LOAD Pin

Resistor ground connection with internal open−on−loss−

of−ground protection

When the ECU experiences a loss of ground condition,

this pin is switched to a high impedance state.

The ground connection through this pin is not interrupted

in any transceiver operating mode including the sleep

mode. The ground connection only is interrupted when

there is a valid loss of ground condition.

This pin provides the bus load resistor with a path to

ground which contributes less than 0.1 V to the bus offset

voltage when sinking the maximum current through one

load resistor.

The transceiver’s maximum bus leakage current

contribution to Vol from the LOAD pin when in a loss of

ground state is 50 mA over all operating temperatures and

3.5 < VBAT < 27 V.

VBAT Input Pin (Vehicle Battery Voltage)

The transceiver is fully operational as described in the

Electrical Characteristics Table over the range 6.0 V <

VBAT < 18 V as measured between the GND pin and the

VBAT pin.

For 5.0 V < VBat < 6.0 V the bus operates in normal mode

with reduced dominant output voltage and reduced

receiver input voltage. High voltage wakeup is not possible

(dominant output voltage is the same as in normal or

high−speed mode).

The transceiver operates in normal mode when 18 V >

VBat > 27 V at 85°C for one minute.

For 0 < VBAT < 4.0 V, the bus is passive (not driven

dominant) and RxD is undriven (high), regardless of the

state of the TxD pin (undervoltage lockout).

CAN BUS Input/Output Pin

Wave Shaping in Normal and High Voltage Wake−Up

Mode

Wave shaping is incorporated into the transmitter to

minimize EMI radiated emissions. An important

contributor to emissions is the rise and fall times during

output transitions at the “corners” of the voltage waveform.

The resultant waveform is one half of a sin wave of

frequency 50−65 kHz at the rising waveform edge and one

quarter of this sin wave at falling or trailing edge.

Wave Shaping in High−Speed Mode

Wave shaping control of the rising and falling waveform

edges are disabled during high−speed mode. EMI

emissions requirements are waived during this mode. The

waveform rise time in this mode is less than 1.0 ms.

Short Circuits

If the CAN BUS pin is shorted to ground for any duration

of time, the current is limited as specified in the Electrical

Characteristics Table until an overtemperature shutdown

circuit disables the output high side drive source transistor

preventing damage to the IC.

Loss of Ground

In case of a valid loss of ground condition, the LOAD pin

is switched into high impedance state. The CANH

transmission is continued until the undervoltage lock out

voltage threshold is detected.

Loss of Battery

In case of loss of battery (VBAT = 0 or open) the

transceiver does not disturb bus communication. The

maximum reverse current into the power supply system

(VBAT) doesn’t exceed 500 mA.

INH Pin

The INH pin is a high−voltage highside switch used to

control the ECU’s regulated microcontroller power supply.

After power−on, the transceiver automatically enters an

intermediate standby mode, the INH output will go high

(up to VBAT) turning on the external voltage regulator. The

external regulator provides power to the ECU. If there is no

mode change within 250 ms (typ), the transceiver re−enters

the sleep mode and the INH output goes to logic 0

(floating).

When the transceiver has detected a valid wake−up

condition (bus HVWU traffic which exceeds the wake−up

filter time delay) the INH output will become high (up to

VBAT) again and the same procedure starts as described

after power−on. In case of a mode change into any active

mode, the sleep timer is stopped and INH stays high (up to

VBAT). If the transceiver enters the sleep mode, INH goes

to logic 0 (floating) after 250 ms (typ) when no wake−up

signal is present

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