Data Sheet TLE 6220 GP

V1.1

Page

26.Aug. 2002

6

Functional Description

The TLE 6220 GP is an quad-low-side power switch which provides a serial peripheral inter-

face (SPI) to control the 4 power DMOS switches, as well as diagnostic feedback. The power

voltage by an active zener clamp.

The diagnostic logic recognises a fault condition which can be read out via the serial diagnos-

tic output (SO).

Circuit Description

Power Transistor Protection Functions

9)

Each of the four output stages has its own zener clamp, which causes a voltage limitation at

the power transistor when solenoid loads are switched off. The outputs are provided with a

current limitation set to a minimum of 3 A. The continuous current for each channel is 1A (all

channels ON; depending on cooling).

Each output is protected by embedded protection functions. In the event of an overload or

short to supply, the current is internally limited and the corresponding bit combination is set

(early warning). If this operation leads to an overtemperature condition, a second protection

level (about 170 °C) will change the output into a low duty cycle PWM (selective thermal shut-

down with restart) to prevent critical chip temperatures.

SPI Signal Description

CS

pin. Whenever the pin is in a logic low state, data can be transferred from the µC and vice

versa.

CS

High to Low transition: - Diagnostic status information is transferred from the power

outputs into the shift register.

- Serial input data can be clocked in from then on.

- SO changes from high impedance state to logic high or low

state corresponding to the SO bits.

CS

Low to High transition: - Transfer of SI bits from shift register into output buffers

- Reset of diagnosis register.

To avoid any false clocking the serial clock input pin SCLK should be logic low state during

pins are ignored and SO is forced into a high impedance state.

9 )

The integrated protection functions prevent an IC destruction under fault conditions and may not be used in normal operation or perma-

nently

.