SPI Driver for Enhanced Relay Control

TLE7239SL

Power Supply

Data Sheet

13

Rev. 1.0, 2010-02-18

5

Power Supply

The TLE7239SL is supplied by two supply voltages

V

and used by the power switches and by an integrated power supply for the register banks. The internal power

supply is designed to hold the state of the power switches including the configuration stored in the control register

bank during cranking down to 4V.There is an under voltage reset function implemented for the

V

which is triggered if

V

are reset to their default values and the device is in sleep mode (standby). Sending the SPI command

CMD.WAKE = 1 switches the device to operation mode (ON), while a command CMD.STB = 1 send the device to

sleep mode (standby) again. Please note that the device needs the time

t

command should be send after changing the power state via CMD.WAKE = 1 before this time is elapsed. A SPI

frame send during

t

The

V

result, the daisy chain function is available as soon as

V

A capacitor between pins

V

5.1

Operation Modes

There is a limp home functionality implemented in the TLE7239SL, which is activated via pin LHI. Please refer to

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 .The sleep mode current is minimized only when limp

home is inactive. After limp home, the device enters sleep mode automatically.

The internal power supply is designed for low voltage cranking condition down to

V

output channels keep their state as before configured via SPI independent of

V

SPI can not be used as the output and input levels refer to

V

the limp home mode is triggered or the

V

The following table shows the operation modes depending on

V

5.2

Limp Home Mode

The TLE7239SL offers the capability of driving dedicated channels during fail-safe operation of the system. This

limp home mode is activated by a high signal at pin LHI. In limp home mode, the SPI registers are reset and the

input pins are directly routed to the auto configuring channels (channel 4 and 5). As a result, the limp home

operation can be chosen for high-side and low-side driven loads. Due to the integrated power supply, limp home

operation is independent of digital power supply

V

device. After limp home operation, the device enters sleep mode in any case.

Operation Modes

VBB

0 V0 V0 V

4 V4 V4 V

12 V

12 V

12 V

12 V

VDD

0 V5 V5 V

0 V0 V3 V

0 V

0 V

5 V5 V

LHI

X

0 V

5 V

0V

4V

0V

0 V

5 V

0V

5V

Switches operating

-

-

-

✓✓✓

✓✓✓✓

Limp Home

-

-

-

-

✓

--

✓

-

✓

SPI & daisy-chain

-

✓

✓

--

✓

--

✓

✓

Register Banks

reset

reset

reset

✓

reset

✓

✓

reset

✓

reset

Diagnostic functions

-

-

----

✓

-

✓

-