Data Sheet TLE 6230 GP

V2.3

Page

18. Nov. 2009

9

high level at this pin (within the data byte) will switch on the power switch, provided that the

corresponding parallel input is also switched on (AND-operation for channel 1 to 4).

SO - Serial Output. Diagnostic data bits are shifted out serially at this pin, the most significant

bit first. SO is in a high impedance state until the CS pin goes to a logic low state. New diag-

nostic data will appear at the SO pin following the rising edge of SCLK.

RESET

- Reset pin. If the reset pin is in a logic low state, it clears the SPI shift register and

switches all outputs OFF. An internal pull-up structure is provided on chip.

Diagnostics

FAULT

- Fault pin. There is a general fault pin (open drain) which shows a high to low transi-

tion as soon as an error occurs for any one of the eight channels. This fault indication can be

used to generate a µC interrupt. Therefore a ‘diagnosis’ interrupt routine need only be called

after this fault indication. This saves processor time compared to a cyclic reading of the SO

information.

As soon as a fault occurs, the fault information is latched into the diagnosis register. A new

error will over-write the old error report. Serial data out pin (SO) is in a high impedance state

when CS is high. If CS receives a LOW signal, all diagnosis bits can be shifted out serially.

There are two diagnostic bits per channel configured as shown in Figure 1.

Normal function: The bit combination HH indicates that there is no fault condition, i.e. normal

function.

Overload, Short Circuit to Battery (SCB) or Overtemperature: HL is set when the current

limitation gets active, i.e. there is a overload, short to supply or overtemperature condition.

Open load: An open load condition is detected when the drain voltage decreases below 3 V

(typ.).

LH bit combination is set.

Short Circuit to GND: If a drain to ground short circuit exists and the drain to ground current

exceeds 100 µA, short to ground is detected and the

LL bit combination is set.

Diagnostic Serial Data Out SO

HH

Normal function

HL

Overload, Shorted Load or Overtemperature

LH

Open Load

LL

Shorted to Ground

Ch.8

Ch.7

Ch.6

Ch.5

15

14

13

12

11 10

9

8

- - - - -

Figure 1: Two bits per channel diagnostic feedback