DRV8432: Input pin capacitance

Basil Mas

Prodigy 60 points

Part Number: DRV8432

Dear TI,

DRV8432.

1) What is the input capacitance of the pins: PWM_A through PWM_D: /RESET_AB and _CD?

2) please give the truth table for input PWM_x v/s output high-side/low-side FET on/off

regards,

Basil

over 7 years ago

0 Rick Duncan over 7 years ago

TI__Guru** 114905 points

Hi Basil,

The input capacitance is typically a few pF ( assume 10pF max )

The truth table is described in section 7.4. Additional information is provided because cycle by cycle current mode affects operation.

0 Basil Mas over 7 years ago in reply to Rick Duncan

Prodigy 60 points

Rick,
Thanks for the info about the capacitance.
The truth table as described in section 7.4 is unclear to me.
I will be more specific; I plan to be using only mode 2 (OC shutdown, no CBC) in my application (dc motor driver). OC current will be set at about 10 Amps.
Will the truth table in mode 2 look like this?
Assuming /Reset_xx is logic 1 (3.3 volts).
PWM_x   HighFET_x    LowFET_x
----------------------------------------------
1    ON    OFF
0              OFF                ON

regards,
Basil

0 Rick Duncan over 7 years ago in reply to Basil Mas

TI__Guru** 114905 points

Hi Basil,

Yes, the truth table would look like you wrote with an additional clarification when PWM_x is 1.

PWM_x HighFET_x LowFET_x
----------------------------------------------
1 ON OFF
0 OFF ON

The output does not support 100% duty cycle because of the bootstrap architecture. Please note section 7.3.2.1 which describes the bootstrap capacitor recharge sequence.

0 Basil Mas over 7 years ago in reply to Rick Duncan

Prodigy 60 points

Hi Rick,

Thanks very much. I understand that. I will limit the duty cycle to allow for bootstrap recharge.

regards,

Basil

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DRV8432: Input pin capacitance