TH8065 Datasheet, PDF (24/40 Pages) Melexis Microelectronic Systems – Voltage Regulator with LIN Transceiver and Watchdog

TH8065
Voltage Regulator with LIN Transceiver and Watchdog
3.9 Mode Input EN
The TH8065 is switched into the sleep mode with a falling edge and into normal mode with a rising edge at
the EN pin. The normal mode will be kept as long as EN = high.
The deactivation of TH8065 with a falling edge at EN can be done independently from the state of the bus-
transceiver.
EN
ESD
voltage
limiter
Filter
6μs
enable
Figure 15 - EN input circuitry
The maximum input voltage is VSUP. The threshold is typ. 1.4V and therefore also 5V and 3.3V CMOS
levels can be used as input signal. Figure 15 shows the internal circuitry of the EN pin.
The EN input has an internal pull down resistor of typ. 23k to secure that if this pin is not connected a low
level will be generated. An input debouncing filter of 6µs suppresses effectively disturbance couplings via the
EN pin
It will use different pull down resistors for normal and sleep mode to minimize the sleep mode current.
The wide input voltage range allows different EN control possibilities. If the EN input is connected to a CMOS
output of the MCU, a falling edge switches the TH8065 into sleep mode (the regulator is also switched off).
The wake up is only possible via the bus line.
V_BAT
LIN
C_IN
220p
TH8065
GND
GND
C_load
VSUP
VCC
EN
RESET
GND
TxD
BUS
RxD
CWD
WDI
GND
GND
MCU
+5V
Figure 16 - EN controlled via MCU
TH8065 – Datasheet
3901008065
Page 24 of 40
May 2006
Rev 003