DRV8432EVM: Had noise issue for DRV8432EVM test

Kevin Huang8

Genius 4515 points

Part Number: DRV8432EVM

Hi Team,

Had noise issue for DRV8432 EVM test:

Using a resistive load (cement resistance), when the input is 100%, the output noise.
Using motor load PWM_A=100% or PWM_B=100% can work normally, but the noise is bigger

DRV8423 EVM test point.docx

over 3 years ago

0 Ryan Kehr over 3 years ago

TI__Guru 55605 points

Kevin,

This device uses a bootstrap architecture to drive high-side NMOS. Therefore, it can't support 100%.

Please tell me more about your application and I can recommend a much newer device with charge pump to support 100% if that is a requirement. Voltage rail? Current need? Motor type?

Regards,

Ryan

0 Kevin Huang8 over 3 years ago in reply to Ryan Kehr

Genius 4515 points

Hi Ryan,

Voltage rail? DC60V

Current need? 正常:5A ;PEAK 7A

Motor type? DC brushed motor

0 Jacob Thompson over 3 years ago in reply to Kevin Huang8

TI__Mastermind 23421 points

Hey Kevin,

The best device for DC60V and 5A is the DRV8962, which is in Preview right now but will be released (active) soon.

We don't have many integrated DC drivers for 60V, so I also recommend looking into using a gate driver instead such as the DRV8770 (new) or the DRV8704 (released 2015).

What PWM frequency are you using? The DRV8432 you're using needs 50ns LOW pulse in the PWM to charge the bootstrap capacitor. For 100kHz PWM this would result in a maximum duty cycle of 99.5%. Calculation: 1 - (50ns / (1/100000) = 0.995 = 99.5%. You might also find section 7.3.2.1 Bootstrap Capacitor Undervoltage Protection useful.

Regards,

Jacob

Motor drivers

Motor drivers forum

DRV8432EVM: Had noise issue for DRV8432EVM test