L99DZ80EP datasheet(37/68 Pages) STMICROELECTRONICS

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L99DZ80EP

Application information

3.16

H-bridge driver slew-rate control

The rising and falling slope of the drivers for the external high-side Power-MOS can be slew

rate controlled. If this mode is enabled the gate of the external high-side Power-MOS is

driven by a current source instead of a low-impedance output driver switch as long as the

drain-source voltage over this Power-MOS is below 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.

Bridge H1/L2 on

110

Slow-decay mode HS1 and HS2

Slow-decay mode HS2 on

Slow-decay mode HS1 on

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

of the other half-bridge remain active and driven by DIR and PWMH

Table 25. H-bridge control truth table (continued)

N°

Control pins Control bits

Failure bits

Output pin

Comment

DIR PWMH HEN SD SDS CP_LOW OV UV DS TSD GH1 GL1 GH2 GL2

L99DZ80EP Datasheet(PDF) 37 Page - STMicroelectronics