STDRIVE102HTR datasheet(16/56 Pages) STMICROELECTRONICS

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5.1.1

12 V LDO linear regulator

This regulator generates the voltage on the VCC pin, which is the supply of the low-side gate drivers and the set

point for the 'VBOOT - VM' voltage provided by the charge pump (refer to Section 5.1.3). A low ESR ceramic

capacitor of 4.7 µF, 25 V must be placed as close as possible to the VCC pin, to ensure the stability of the VCC

and support the currents required by the low-side gate drivers.

In addition, external loads can be connected to VCC pin, taking care to stay within the operating range. The

output current of the regulator is limited at ICC,lim protecting it against short circuit and overload. The overall

consumption of the external loads plus the drivers must be smaller than this current limitation.

Figure 6. 12 V LDO output according to the current load at different VS input

Load current [mA]

VS > 13 V

VS = 12 V

VS = 6 V

The linear regulator input is connected to the main supply VS. The regulator can be bypassed by connecting the

VCC and the VS together and forcing an external voltage equal to the target VCC value, which must be in any

case within the operative range of the VCC pin.

The regulator is disabled in standby mode in order to reduce the current consumption.

In case the VCC voltage falls below the UVLO threshold (VCC(Off)), the gate drivers turn off all the external

MOSFETs, forcing the power stage into a safe condition. Concurrently, the nFAULT open-drain pin is forced low to

signal that the UVLO protection has been triggered. As soon as the VCC voltage rises above the VCC(On)

threshold, the nFAULT is released and the drivers return to an active condition, according to the status of the

digital inputs.

In the STDRIVE102BH only when the VCC voltage falls below the “power-good” threshold (VP_GOOD(Off)), the

FLAG open-drain pin is forced low, but there are no other effects on the functional blocks of the devices. The

FLAG pin is then released as soon as the VCC voltage rises above the VP_GOOD(On) threshold.

An example of the VCC thresholds management is shown in Figure 7.

STDRIVE102BH, STDRIVE102H

Device description

DS14545 - Rev 1

page 16/56

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