DRV8837: Swiching noise in DRV8837 simulation

Vladislavas Cerkasovas

Part Number: DRV8837
Other Parts Discussed in Thread: DRV8838, , DRV8873-Q1,

Hi,

There are two questions regarding DRV8837/DRV8838 motor driver IC.

1. I did a simple test in LTspice using DRV8837. I set In1 to 0V and IN2 to 3.3V. I expect to see a DC signal on the output, but the simulation shows that there is some sharp peaks appearing on the output. You can see the output of simulation on the attached picture. These peaks are getting weaker if I add a capacitance on the output. Why I am seeing some switching while the inputs are being held at constant level? Is it an activity of the internal charge pump? And how should I deal with this noise?

2. I want to use this IC for bidirectional Peltier element driver. I want to connect a linear current source to the VM and use DRV8837 for direction switching. Should be there some issues with this consept? The voltage and current ranges should be [0 to 3V] and [0-1A] respectively.

Thanks in advance!

over 3 years ago

0 Pablo Armet over 3 years ago

TI__Mastermind 37683 points

Hi Vladislavas,

Thank you for posting to the motor drives forum.

We'll start working on answering your questions. Expect a reply from us by 11/24 (US time) or earlier.

0 Pablo Armet over 3 years ago in reply to Pablo Armet

TI__Mastermind 37683 points

Hi Vladislavas,

I was able to recreate the same simulation results as you did. The charge pump frequency is much higher that the frequency of the spikes so this is not the cause. After looking at the simulation results closely, this might be an issue with the spice model rather than the device. I will talk with the spice model designers to find the root cause and will let you know as soon as we find the cause. Expect a follow up from me by 11/30 or earlier.
Based on the voltage and current requirements, the DRV8837 can be used as a TEC driver. I suggest reading this application note on driving a peltier element (https://www.ti.com/lit/an/slua979a/slua979a.pdf?ts=1606240090508&ref_url=https%253A%252F%252Fwww.ti.com%252Fsitesearch%252Fdocs%252Funiversalsearch.tsp%253FsearchTerm%253Dtec%2Bmotor%2Bdriver). This app-note shows an example on how to drive a TEC element using the DRV8873-Q1 but the same concept can be applied to the DRV8837.

0 Pablo Armet over 3 years ago in reply to Pablo Armet

TI__Mastermind 37683 points

Hi Vladislavas,

It was confirmed that there is an issue with the spice model that is causing the spikes to appear at the output. Unfortunately, this is a problem that will not be able to be fixed at this moment.

If you want to test and evaluate the DRV8837, we have the DRV8837EVM evaluation board you can order from ti.com.

I apologize if the issue with the spice model has caused an inconvenience to you.

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DRV8837: Swiching noise in DRV8837 simulation