TH8056

Enhanced Single Wire CAN Transceiver

TH8056 – Datasheet

Page 13 of 26

3901008056

March 2007

Rev 012

3.5

Vehicle Battery Voltage

between the GND pin and this pin.

receiver input voltage. High voltage wake-up call is not possible (dominant output voltage is the same as in

normal or high-speed mode).

one minute.

the state of the TxD pin (under-voltage lock-out).

3.6

CAN BUS pin

Bus Input/Output

Wave Shaping in normal and HVWU 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 sine wave of frequency 50 – 65 kHz at the rising

waveform edge and one quarter of this sine wave at falling or trailing edge.

Short circuits

If the CAN BUS pin is shorted to ground for any duration of time, the current is limited to the specified value,

until an over-temperature shut-down circuit disables the output high side drive source transistor (before the

local die temperature exceeds the damage limit threshold).

Loss of ground

In case of an ECU loss of ground condition, the LOAD pin is switched into high impedance state. The CANH

transmission is continued until the under-voltage lock-out voltage threshold is detected.

Loss of battery

In case of battery loss (VBAT = 0 or open) the transceiver does not disturb bus communication. The

maximum reverse current into power supply system doesn’t exceed 500µA.

3.7

INH Pin (TH8056 KDC A only)

This Pin is a high-voltage highside switch used to control the ECU’s regulated microcontroller voltage supply.

After power-on the transceiver automatically enters an intermediate standby mode, the INH output will

become HIGH (VBAT) and therefore the external voltage regulator will provide the Vcc supply for the ECU .

If there is no mode change within the time stated, the transceiver reenters 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 (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 keeps high (VBAT) level. If the transceiver enters the sleep mode (M0,1=0),

INH goes to logic 0 (floating) no sooner than 100ms when no wake-up signal is present.