TPIC44L01, TPIC44L02, TPIC44L03

4CHANNEL SERIAL AND PARALLEL LOW SIDE PREFET DRIVER

15

POST OFFICE BOX 655303

PRINCIPLES OF OPERATION

over-battery-voltage shutdown

The TPIC44L01,TPIC44L02, and TPIC44L03 monitor the battery voltage to prevent the power FETs turning on

in the event that the battery voltage is too high. This condition may occur due to voltage transients resulting from

a loose battery connection. The TPIC44L01, TPIC44L02, and TPIC44L03 turns the power FET off when the

battery voltage is above 34 V to prevent possible damage to the load and the FET. GATE(0–3) output goes back

to normal operation after the overvoltage condition has been corrected. An over-battery voltage fault is flagged

to the controller through FLT. The over-battery voltage fault is not reported in the serial fault word. When an

overvoltage condition occurs, the device reports the battery fault, but disables fault reporting for open and

shorted-load conditions. Fault reporting for open and shorted-load conditions are reenabled after the battery

fault condition has been corrected. When the fault condition is removed before the CS signal transitions low,

the fault condition is not captured in the serial fault register. The fault flag resets on a high-to-low transition of

CS provided no other faults are present in the device. Figure 16 illustrates the operation of the over-battery

voltage detection circuit.

_

+

VBAT

34 V

34 V

33 V

12 V

VBAT

GATE0–GATE3

Output Disable

U1

Figure 16