TLE7237GS Datasheet, PDF (13/36 Pages) Infineon Technologies AG – 8 Channel High-Side and Low-Side Relay Switch

TLE7237GS
Power Supply
5
Power Supply
The TLE7237GS is supplied by two supply voltages V_bb and V_DD. The V_bb supply line is connected to a battery
feed and used by the power switches and by an integrated power supply for the register banks. There is an under
voltage reset function implemented for the V_bb power supply. After start-up of the power supply, all SPI registers
are reset to their default values and the device is in sleep mode (standby). The SPI command CMD.WAKE = 1 is
switching the device to operation mode (ON), while a command CMD.STB = 1 send the device to sleep mode
(standby) again.
The V_DD supply line is used by the SPI shift register related circuitry and for driving the SO line. As a result, the
daisy chain function is available as soon as V_DD is provided in the specified range independent of V_bb. A capacitor
between pins V_DD and GND is recommended (especially in case of EMI).
The device provides a sleep mode (stand by) to minimize current consumption, which also resets the register
banks. It is entered and left by dedicated SPI commands or by turning off the VDD supply.
5.1
Reset
There are several reset trigger implemented in the device. A reset switches off all channels and sets the registers
to default values. After any kind of reset, the transmission error flag (TER) is set.
Under Voltage Reset:
During this device condition a read on SPI always delivers the Standard Diagnostic Frame with a TER flag.
This under voltage reset is released when all the supply voltages levels are above under voltage threshold.
Reset Command: There is a reset command available to reset all register bits of the register bank and the
diagnosis registers. As soon as CMD.RST = 1, a reset is triggered.
Data Sheet
13
Rev. 1.0, 2008-10-30