L99H01 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'L99H01' PDF : 53 Pages View PDF
Device description
L99H01
VVS_UV, all gate driver stages are switched in the sink condition to avoid driving the power
devices without sufficient gate driving voltage (increased power dissipation), setting the UV
bit. In both cases, overvoltage and undervoltage detection, the charge pump is disabled. If
the supply voltage VS recovers from UV/OV to normal operating voltage range and if the
OV_UV_RD is set to 0, then the charge pump is automatically enabled. In any case,
regardless of the OV_UV_RD bit value, the microcontroller needs to clear the status register
to reactivate the gate drivers.
3.7
Charge pump
The charge pump uses 2 external capacitors. The output of the charge pump has a current
limitation. In standby mode and after overvoltage, undervoltage or a thermal shutdown has
been triggered the charge pump is disabled. If the charge pump output voltage remains too
low for longer than TCP , all gate drivers are switched-off (resistive output, see Section 3.4).
The CP_LOW bit has to be cleared through a software reset to reactivate the gate drivers.
3.8
Temperature warning and thermal shutdown
If junction temperature rises above TjTWON the temperature warning flag TW is set and is
detectable via the SPI. If junction temperature increases above the second threshold
TjSDON, the thermal shutdown bit (TSD) is set. The gate drivers and the charge pump are
switched-off to protect the device. The gates of the H-bridge are discharged by the resistive
low mode (see Section 3.4). In order to reactivate the output stages the junction
temperature must decrease below Tj SD OFF and the thermal shutdown bit has to be cleared
by the microcontroller.
3.9
Short-circuit detection / drain source monitoring
The drain - source voltage of each activated external MOSFET of the H-bridge is monitored
by comparators to detect shorts to ground or battery. If the voltage drop over the external
MOSFET exceeds the threshold voltage VSCd for longer than the short current detection
time tSCd the corresponding gate driver switches the external MOSFET off and the
corresponding drain source monitoring flag (DS_MON [3:0]) is set. Until this failure flag is
reseted the corresponding half bridge is in sink condition. The DS_MON bits have to be
cleared through a software reset to reactivate the gate drivers. The drain source monitoring
has a filter time of 6 µs. This monitoring is only active when the corresponding gate driver is
in source condition. The threshold voltage VSCd can be programmed in 4 steps between
0.5 V and 2 V with the SPI.
3.10
Programmable cross current protection
The external Power MOSFET’s transistors in H-bridge (two halfbridges) configuration are
switched-on with an additional delay time tCCP to prevent cross current in the halfbridge.
The cross current protection time tCCP can be programmed with the SPI.
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DocID15567 Rev 5
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