L99ASC03 datasheet(21/73 Pages) STMICROELECTRONICS

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L99ASC03

Device description

shoot-through protection. The minimum tCCP is applied between outputs GHx and GLx only

if a lower (or null) dead-time is present between inputs ILx and IHx (see Figure 18). In case

the IHx and the ILx input of a half bridge are active at the same time, both gate driver

outputs (high side and low side) are turned off. In addition, if IHx and ILx are both driven

active for longer than tCCP, the affected half bridge is disabled and the ST(x) error flag is set.

To re-enable the half bridge, this fault condition has to be removed and the corresponding

ST(x) flag has to be reset through an SPI "Read & Clear" command.

The gate driver circuit limits the gate-source voltage of the external MOSFETs. All gate

driver circuits are independent of each other and use their source connection to the external

MOSFET as a reference.

In order to drive different MOSFETs and adjust the gate currents according to external

conditions (e.g. temperature), the source and sink current (i.e. the charging and discharging

current) of the gate driver can be programmed via SPI.

The HARDOFF feature is an additional measure against cross-current conduction in a half

bridge. When the HOFFCONT bit is set to 0, any of the outputs GHx and GLx is switched off

using maximum sink current (max PCSI) after a tCCP from related turn-off command. When

the HOFFCONT bit is set to 1, any of the outputs GHx and GLx is switched off using

maximum sink current (max PCSI) as soon as the complementary output signal

(respectively GLx or GHLx) goes to high.

Figure 11. HARDOFF functionality by using internal dead time

Propagation delay is omitted for convenience.

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