STCMB1 datasheet(50/59 Pages) STMICROELECTRONICS

50 / 59 page

Application information

STCMB1

50/59

DocID028958 Rev 4

bootstrap capacitor from being charged to a voltage exceeding the absolute maximum

rating (21 V), in case of significant negative spikes on the half-bridge midpoint when the

high-side MOSFET turns off.

Both high-side and low gate drivers have a DMOS structure driving the MOSFET gates. The

current capability is 0.3 A at the MOSFET turn-on and 0.6 A at turn off, giving typical rise

and fall times of 60 ns and 30 ns respectively.

Both drivers have pull-down circuitry active before the start-up to keep the MOSFETs safely

off against an unwanted turn-on due to the environment noise: the HVG has an internal pull-

down resistor (27 k

 typ.) connected among the HVG and OUT pin, while the LVG driver

has active pull-down circuitry. Both them allow removing the typical gate-source resistance

or using a higher value.

It has to be noted that the drivers have no any voltage clamping of the gate voltage.

Therefore the MOSFETs will be driven with a driving voltage at the VCC level. For this

reason the VCC will have to be limited in all operating or fault condition to a safe level, to

avoid any premature aging or damaging of the MOSFETs gate oxide.

STCMB1 Datasheet(PDF) 50 Page - STMicroelectronics