DRV8802-Q1; how to activate this device

Hi Yamamoto-san,

The voltages on V3P3OUT and CP1 point to the device being in sleep mode. Please check the connection to nSLEEP at the pin.

Is VMB connected to 11V also?

Can you provide a schematic and layout? I can provide details on how to send it if the schematic and layout cannot be posted here.

Dear Rick,

Thank you for your reply.

My customer sets nSLEEP to high. *See attachment file

VMB is also 11V.

I added their schematic to previous file.

Please see attachment file and teach me your advices.

4300.DRV8802schematic&setting.pdf

Best regards,

Hi Yamamoto-san,

Thank you for the information. The schematic looks good.

In my opinion, the first item to focus on is the V3P3OUT and VCP voltages. These must be resolved prior to the output working. The device appears to be in sleep mode.

Please ask the customer to examine the voltages at the pins of the device, or verify continuity to the pins from the point the probe was placed.

If possible, please disconnect the motor from the DRV8802. This should prevent any UVLO issues when debugging.

For V3P3OUT to work, the following pins must be connected:
1) GND pins 14 and 28 -- The schematic does not show these connected. Are they connected?
2) VMA and VMB -- at least 8.2V is required to activate the device
3) CP1, CP2 and VCP using the recommend capacitors
4) nSLEEP = 3.3V

Once the device is awakened (V3P3OUT = ~3.3V), the next step is to enable the device using AENBL. The outputs should follow the truth table at that point. If not, please provide scope captures of the VCP and the outputs.

If this shows nothing, the device could be damaged. Has the customer tried multiple boards or replaced the device? Is the same failure seen on multiple boards or when the device is replaced?

If the problem appears on multiple boards, can you provide the layout?

Dear Rick,

Thank you for your reply and kindness advice!

Now I have asked customer to check.

However I want check one thing about your advice, and two things about my concern.

1, What is the mean of your advice 'to examine the voltages at the pins of the device, or verify continuity to the pins from the point the probe was placed.'?

My customer check almost of pins.

Are there needs to check other pins?

2, Is it no problem to connect V3P3OUT, AVREF and BVREF directly like their schematic?

They connected these pins in order to I(CHOP) = 1.523A.

Does connecting directly occur some problem?

3, Is there waiting time to rise up ENBL from rising up nSLEEP?

From attachment file at my previous post, my customer rise up ENBL 2.8 ms after rising up nSLEEP.

Is this enough?

Best regards,

Hi Yamamoto-san,

I missed the nRESET connection on the schematic yesterday. This should be connected to an active high. If low, the outputs will not enable. Please make sure nRESET is driven high.

This does not explain V3P3OUT at 0V.

Takao Yamamoto said:

1, What is the mean of your advice 'to examine the voltages at the pins of the device, or verify continuity to the pins from the point the probe was placed.'?

My customer check almost of pins.

Are there needs to check other pins?

Sometimes the voltage is checked at test points instead of at the physical pin of the device. If there is a broken trace or cold solder joint, the pin may not be making connection to the test point.

If the nSLEEP pin is not connected, the device will not wake up. V3P3OUT will remain low and VCP will not be at ~ VM +10V.

If more than one board shows the same behavior, the broken trace or cold solder joint is unlikely.

Takao Yamamoto said:

2, Is it no problem to connect V3P3OUT, AVREF and BVREF directly like their schematic?

They connected these pins in order to I(CHOP) = 1.523A.

Does connecting directly occur some problem?

There is no problem connecting the pins as shown.

Takao Yamamoto said:

3, Is there waiting time to rise up ENBL from rising up nSLEEP?

From attachment file at my previous post, my customer rise up ENBL 2.8 ms after rising up nSLEEP.

Is this enough?

No, there is no waiting time from nSLEEP rising.

As previously mentioned, the schematic does not show the ground connection to the DRV8802