DRV8842 catch diode voltage

doginwater

Intellectual 340 points

Other Parts Discussed in Thread: DRV8842

Hi,

Looking to use the DRV8842 to drive a solenoid, trying to figure out the power dissipation.

For the power fets, what is voltage across the catch diode during the recirculation phase? The current is about 0.6A.

Regards,

over 9 years ago

0 Wilson Zuo over 9 years ago

TI__Mastermind 26065 points

Hi Lejun

The body diodes forwarding voltage drop is very similar to normal diodes. It will be changing refer to the current level. The range could be 0.7V to 1.1V. Since the catch voltage, the recirculation current are all not constant value during each cycling, you can just use 0.8V to 1V for the recirculation power estimation.

Best regards,

0 doginwater over 9 years ago in reply to Wilson Zuo

Intellectual 340 points

Ok so if I understand this correctly:

0.6A * 1V = 0.6W,
@35C/W, a FET used as a body diode diode will increase current by 20C, assuming heat sinking done using the JEDEC standard board specified.

0 doginwater over 9 years ago in reply to Wilson Zuo

Intellectual 340 points

Does TI provide TINA models for this chip?

0 Rick Duncan over 9 years ago in reply to doginwater

TI__Guru** 114905 points

Hi Lejun,

There is no TINA model for this device. For a list of devices that have models, navigate to http://webench.ti.com/webench5/spicemodels/

From there select "Amplifiers and Linear" in the "Search for models in" pulldown

Next enter "DRV" in the search window, and select the search icon.

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DRV8842 catch diode voltage