TH8056_12 Datasheet, PDF (17/34 Pages) Melexis Microelectronic Systems – Enhanced Single Wire CAN Transceiver

TH8056
Enhanced Single Wire CAN Transceiver
The transceiver’s maximum bus leakage current contribution to V_ol from the LOAD pin when in a loss of
ground state is 50 uA over all operating temperatures and 3.5 V < V_batt < 26.5V.
3.5 V_bat INPUT pin
Vehicle Battery Voltage
The transceiver is fully operational as described in chapter 2 over the range 6V<V_{bat IC}<18V as measured
between the GND pin and this pin.
For 5V < V_{bat IC} < 6V the bus operates in normal mode with reduced dominant output voltage and reduced
receiver input voltage. High voltage wake-up call is not possible (dominant output voltage is the same as in
normal or high-speed mode).
The transceiver operates in normal mode and high-voltage wake-up mode if 18V < V_{bat IC} < 26.5V at 85°C for
one minute.
For 0V< V_{bat IC} < 4.8V, the bus is passive (not driven dominantly) and RxD is undriven (high), regardless of
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 .
TH8056 – Datasheet
3901008056
Page 17 of 34
June 2012
Rev 014