TH8062 Datasheet, PDF (15/38 Pages) Melexis Microelectronic Systems – Voltage Regulator with LIN Transceiver

TH8062
Voltage Regulator with LIN Transceiver
3.2 Initialization
Initialization starts when the power supply is switched on as well as every rising edge on of the TH8062 via
the EN pin.
VSUP- Power-ON
If V_SUP is switched on the TH8062 starts to normal mode via the POR- and Ini-state. A combination of
dynamic POR and under voltage reset circuitry generates a POR signal, which switches the TH8062 into
normal mode. This power on behaviour is independent from the status of the EN-pin.
Power-on reset and under-voltage reset operate independent from each other, which secures the
independence from the rise time of VSUP. During fast VSUP edges the power-on reset will be active. If the
increasing of VSUP is very slow (> 1ms/V) and V_SUP > V_{SUVR_OFF} (typ. 4.2V) the under voltage reset unit
initializes the voltage regulator.
The effects of both POR circuits at different VSUP slopes will show in Figure 6.
VSUP
V _{SUVR_OFF}
V_{SUVR_ON}
UVR
VCC
POR
EN=H/L
POR
UVR
normal mode
sleep mode
normal mode
Figure 6 - Operating of power-on and under-voltage reset
After POR the voltage regulator starts and the VCC voltage will be output. If V_CC>V_MRes the bus interface will
be activated. If the V_CC voltage level is higher than V_RES, the reset time t_Res is started. After t_Res the RESET
output switches from low to high (see Figure 11).
The Initialization procedure operates after POR independent from the EN voltage.
Start of Linear Regulator via Wake-up
The initialization is only being done for the VCC circuitry parts. This procedure begins with leaving the master
reset state (V_CC > V_MRes) and runs in the same manner as the VSUP-Power-On.
3.3 Wake-Up
If the regulator is put into sleep mode it can be woken up with the BUS interface. Every pulse on the BUS
(high pulse or low pulse) with a pulse width of min. 70μs switches on the regulator.
The low slew mode has to be selected again if necessary.
After the BUS has woken up the regulator, it can only be switched off with a high level followed by a low level
on the EN pin.
TH8062 – Datasheet
3901008062
Page 15 of 38
March 2006
Rev 002