TPIC0107B

PWM CONTROL INTELLIGENT HBRIDGE

SLIS067A − NOVEMBER 1998 − REVISED APRIL 2002

9

POST OFFICE BOX 655303

PRINCIPLES OF OPERATION

drop across the DMOS outputs against the threshold voltage. The DMOS outputs of the TPIC0107B will be

disabled and the fault flags will be generated 10

µs after an over-current or short-circuit fault is detected. This

10

µs delay is long enough to serve as a de-glitch filter for high current transients, yet short enough to prevent

damage to the DMOS outputs. The DMOS outputs remain latched off until either DIR or PWM input is toggled.

In cases where the outputs have a continuous short-to-ground with a current rise time faster than 0.5 A/

µs, the

over-current shutdown threshold will decrease to 3 A to reduce power dissipation. This reduction to 3 A is

achieved since the DMOS outputs will not be fully enhanced when the over-current threshold is reached if the

current rise time exceeds 0.5 A/

and a junction temperature of 90

°C.

over temperature

outputs remain latched off until either DIR or PWM input is toggled.

under voltage

over voltage

In order to protect the DMOS outputs from damage caused by excessive supply voltage, the TPIC0107B

re-enable the DMOS outputs.

cross conduction

Monitoring circuitry for each transistor detects whether the particular transistor is active to prevent the HSD or

LSD of the corresponding half H-bridge from conducting.

open circuit

During operation, the bridge current is controlled continuously. If the bridge current is >10 mA (min.) for a period

>1 ms (min.), the fault flags are set. However, the output transistors will not be disabled.

† All limits mentioned are typical values unless otherwise noted.

‡ If a short circuit occurs (i.e., the over-current detection circuitry is activated) at a supply voltage higher than 16.5 V and a junction temperature

higher than 90

°C, damage to the device may occur.