DRV8932PRGER datasheet(13/40 Pages) TI

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time settings can be changed on the fly. After a OFF time setting change, the new OFF time is applied after a 10

µs de-glitch time.

For resistive loads connected to VM, if the ITRIP is higher than the (VM / RLOAD), the load current is regulated at

VM / R LOAD level while INx = 0. For inductive loads connected to VM, it should be ensured that the current

decays enough every cycle to prevent runaway and triggering overcurrent protection. The different scenarios are

shown below -

Figure 7-3. Resistive Load Connected to VM, Cycle-by-cycle control, ITRIP is higher than VM/RLOAD.

Figure 7-4. Inductive Load Connected to VM, fixed off-time current chopping

In this scenario, with INx = 0, the high-side MOSFET is turned on for tOFF duration after IOUT exceeds ITRIP.

After t OFF, the low side MOSFET is again turned on till IOUT exceeds ITRIP again. The fixed off-time mode

allows for a simple current chopping scheme without involvement from the external controller. Fixed off-time

mode will support 100% duty cycle current regulation.

Another way of controlling the load current is the cycle-by-cycle control mode, where PWM pulse width of the INx

input pins are controlled. This allows for additional control of the current chopping scheme by the external

controller. For loads connected to VM, when INx = 0, the current through the load builds up; and when INx = 1,

the current through the load decays. By properly choosing the duty cycle of the INx pulse, current can be

regulated to a target value. Various such scenarios are shown below -

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DRV8932

SLOSE58A – MAY 2020 – REVISED NOVEMBER 2020

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DRV8932PRGER Datasheet(PDF) 13 Page - Texas Instruments