L99DZ320 datasheet(71/146 Pages) STMICROELECTRONICS

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Control pins

Control bits

Failure bits

Output pin

Mode

Description

Half bridge mode

1. Only the half bridge (low-side and high-side), in which one Power MOSFET is in short-circuit condition is switched off. Both Power

MOSFETs of the other half bridge remain active and driven by DIRH and PWMH.

H-bridge is forced off during long open window until watchdog kicks in short window, keeping control bits

accessible in the meanwhile.

3.25

H-bridge driver slew rate control

The rising and falling slope of the drivers for the external high-side Power MOSFET can be slew rate controlled. If

this mode is enabled the gate of the external high-side Power MOSFET is driven by a current source instead of a

low impedance output driver switch as long as the drain-source voltage over this Power MOSFET is above the

switch threshold. The current is programmed using the bits SLEW<4:0>, which represent a binary number. This

number is multiplied by the minimum current step. This minimum current step is the maximum source/sink current

(IGHxrmax/IGHxfmax) divided by 31. Programming SLEW<4:0> to 0 disables the slew rate control and the output is

driven by the low impedance output driver switch.

Note:

To avoid crosscurrent conduction, it must be avoided the usage of the lowest slew rate configurations.

L99DZ320

Functional description

DS14235 - Rev 5

page 71/146

L99DZ320 データシート(PDF) 71 Page - STMicroelectronics