DRV8432 / PVDD capacitance value

Ryuji

Guru 20090 points

Hello,

There are 1000uF capacitance at the PVDD In the datasheet P.15 Figure 8.

Since our customer uses 2pcs of DRV8432, they need 2000uF cap for PVDD(they use 24V for PVDD).

The Power supply for PVDD has some problem(for example, inrush current etc.) due to this large capacitance.

Could you please let me know the calculation for PVDD cap ?

They would like to reduce the capacitance from 2000uF to 200uF.

Best Regards,

Ryuji Asaka

over 11 years ago

0 Nicholas Oborny over 11 years ago

TI__Mastermind 21305 points

Hi Ryuji,

Bull capacitance for the supply is very dependent on the application requirements.

Will you be spiking the supply with heavy braking? What is the typical operating current? How are far is the device located from the power supply? What is the power supply?

Any information you can provide will be helpful.

0 Ryuji over 11 years ago in reply to Nicholas Oborny

Guru 20090 points

Hello Nicholas san,

Thank you for the reply.

I requested infomration to our customer.

I will post again until end of this week.

Best Regards,

Ryuji Asaka

0 Ryuji over 11 years ago in reply to Ryuji

Guru 20090 points

Hello Nicholas san,

I got customer information.

Please see the attached file.

7128.DRV8432.pdf

Can we reduce the bulk capacitance from 1000uF to about 200uF ?

Best Regards,

Ryuji Asaka

0 Nicholas Oborny over 11 years ago in reply to Ryuji

TI__Mastermind 21305 points

Hi Ryuji-san,

For a TEC driver you should be OK reducing this capacitance.

A general rule of thumb we use is 2uF/W for motor drivers so I would recommend a value somewhere between 200uF-400uF for each driver.

Motor drivers

Motor drivers forum

DRV8432 / PVDD capacitance value