DRV8210EVM: DRV8210EVM

Ali Khan

Part Number: DRV8210EVM

Tool/software:

Hi,
I order this EVM board to test sleep mode current of DRV8210DRLR.
https://www.digikey.ca/en/products/detail/texas-instruments/DRV8210EVM/13627112

I also populated following for current sensing circuit on board

TLV9001TIDCKR U4,
100mOHM R20.
3.4K R17 ,
165K R18 on board

Now I need some guidance how i can test the sleep mode current on this board at I sense pin using DMM. I can see some voltages change with rotating potentiometer without load.
The main goal is to verify the sleep mode current. How i can put this chip in sleep mode without load. The input supply i am applying for VM is 7V.
Thanks

9 months ago

0 Murugavel4637 9 months ago

TI__Guru 55135 points

Hi Ali,

Thanks for your question.

Ali Khan said:
How i can put this chip in sleep mode without load. The input supply i am applying for VM is 7V.

The DRL package device will enter sleep mode automatically when both IN1 and IN2 is 0 for longer than tAUTOSLEEP time. The sleep mode current is also published in the datasheet.

Ali Khan said:
The main goal is to verify the sleep mode current.

See below IVMQ sleep current vs. VM voltage across various temperatures. We have verified and characterized this current for a bunch of devices with various operating ambient temperatures TA and VM supply voltages for publishing this plot in the datasheet. What is the reason you'd want to verify this current again. According to this plot at VM = 7 V, the sleep mode current IVMQ will be about 100 nA.

Ali Khan said:
ow I need some guidance how i can test the sleep mode current on this board at I sense pin using DMM. I can see some voltages change with rotating potentiometer without load.

The VM rail in the EVM distributes power to the other devices onboard the EVM via the LDO regulator U1. If you measure the current supplied via the VM input using a DMM you must isolate other loads and leave only the U5 driver (remove U2) in the EVM powered by VM to get accurate sleep mode readings. R1 must be removed during this measurement to cut off power consumed by U1 and its load on VCC. Keep in mind there might be some additional leakage currents on VM due to C3, C6, C9 and C10 if it was populated. If these must be accurately accounted for they must be removed for the sleep current measurement as well. Thank you.

Regards, Murugavel

0 Ali Khan 9 months ago in reply to Murugavel4637

Expert 1150 points

Hi Murugavel4637

Thanks for detailed reply.

1: I am using current sense circuit on evm board to find the current consumption. I bought the evm(link shown above). I am not sure what exact part number populated on evm board. I attached a picture of the package for your reference.

I solder current sensing circuit and i can see voltages across evm isense pin.

So i am not measuring voltages at input side but at isense pin that amplify across the current sense resistor in evm board.

Let me know if you need me to explain further.

0 Murugavel4637 9 months ago in reply to Ali Khan

TI__Guru 55135 points

Hi Ali,

Thanks for the clarification.

Ali Khan said:
1: I am using current sense circuit on evm board to find the current consumption. I bought the evm(link shown above). I am not sure what exact part number populated on evm board. I attached a picture of the package for your reference.

This would be the DSG package DRV8210DSGR. It is not the DRL package. Please ignore my previous reply which was my response to DRL package device.

Ali Khan said:
I solder current sensing circuit and i can see voltages across evm isense pin.

So i am not measuring voltages at input side but at isense pin that amplify across the current sense resistor in evm board.

I assume you changed R20 from 0 Ω to a desired current sense resistor value and populated the C11 capacitor. What value did you use for R20? As well as the components C5, R17 and R18 were populated. With the mentioned values for R17 and R18 the gain of this current amplifier would be approx. 20. This would amplify the voltage across sense resistor R20 by x20. Vout amp = (Iload x R20) x 20.

This current sensing circuit is for sensing the load current only. With no load the load current = 0, the amplifier output would be x20 of the amplifier offset voltage which may be very small. Note, this sensor cannot measure the driver's sleep mode current. In sleep mode the load current would be 0.

Ali Khan said:
I solder current sensing circuit and i can see voltages across evm isense pin.

Was this load connected or no load? How much was the measured voltage? Thank you.

Regards, Murugavel

0 Ali Khan 9 months ago in reply to Murugavel4637

Expert 1150 points

Hi Murugavel4637

I used the components mentioned in my first message.

TLV9001TIDCKR U4,

100mOHM R20.

3.4K R17 ,

165K R18 on board

Now when both potentiometer anticlockwise all the way, then i get 0.1V at ISENSE PIN with no load.

If i change the potentiometer to clockwise then it start giving me output voltages mV to some higher voltage. No load again

I will make a video for your reference with complete details tomorrow.

Thanks

0 Murugavel4637 9 months ago in reply to Ali Khan

TI__Guru 55135 points

Hi Ali,

Understood, thanks. This works out to a gain of around 50x.

Ali Khan said:
Now when both potentiometer anticlockwise all the way, then i get 0.1V at ISENSE PIN with no load.

These two potentiometers are inputs to the onboard MSP430 microcontroller. These analog levels are converted into PWM variable duty cycle IN1 and IN2 for PWM mode and IN1/EN PWM for PH/EN mode, where the PH is controlled by the other potentiometer has to be on either ends for a low or a high.

Please measure the voltage across the sense resistor R20 by setting the meter in sensitive mV range. With no load this should read very low value regardless of the potentiometer settings. The amplifier output should be 50x the measured voltage across the R20.

Perform a test with MODE setting set to high for PH/EN mode before turning on the power supply. Turn the EN/IN1 potentiometer fully clockwise for 100 % PWM duty output and set the PH/IN2 potentiometer fully counter clockwise for one direction. Now measure the voltage on R20 and the amplifier output. R20 voltage should be very low mV (offset of the amp) and the amplifier output would be 50x that value. Next connect a 20 Ω resistance as test load at the output. With 7 V the load current would be 0.35 A. Be sure to use a 5 W resistor and keep in mind the load resistor might get hot - please follow safety to avoid burns. In this condition the voltage on R20 would be (offset + 0.35 x 0.1) = offset + 0.035 and the amp output would be around 0.035 x 50 = 1.75 V + (offset x 50). Thank you.

Regards, Murugavel

0 Ali Khan 9 months ago in reply to Murugavel4637

Expert 1150 points

Hi Murugavel4637
Here is the test results based on above settings you asked.
N/IN1 potentiometer fully clockwise for 100 % PWM duty output and set the PH/IN2 potentiometer fully counter clockwise for one direction. MODE setting set to high for PH/EN mode before turning on the power supply

Input Voltage 7V and Input current setup at 0.5A and board is consuming 0.008A at power supply display. The voltage across R20 is 0.2mV and Voltage at Isense pin is 2.8mV
I don't have 5W resistor so i can't test that part. I tried to test with 1/4W but it burned out obviously.

Let me know if there is any other test that we can do. The main thing, i need to verify is the sleep mode current. I don't mind about load current for now.
Thanks

0 Murugavel4637 9 months ago in reply to Ali Khan

TI__Guru 55135 points

Hi Ali,

Ali Khan said:
Input Voltage 7V and Input current setup at 0.5A and board is consuming 0.008A at power supply display. The voltage across R20 is 0.2mV and Voltage at Isense pin is 2.8mV

Please clarify what you meant by Isense pin. Was it the AMP_OUT?

Ali Khan said:
don't have 5W resistor so i can't test that part. I tried to test with 1/4W but it burned out obviously.

Without a load resistor you won't be able to test the load current.

Ali Khan said:
The main thing, i need to verify is the sleep mode current.

To ensure the device is in sleep mode please do the following.

Power off the EVM.
Connect the MODE selection jumper short to GND - see below. This will set the device in PWM mode when it powers up.
Set both potentiometers in completely counter clockwise position.
Power on the EVM.
Wait for > 2.6 ms.
The device will be in sleep now.

Thank you.

Regards, Murugavel

0 Ali Khan 9 months ago in reply to Murugavel4637

Expert 1150 points

Yes AMP_OUT pin same as Isense pin ON EVM.

0 Murugavel4637 9 months ago in reply to Ali Khan

TI__Guru 55135 points

Hi Ali,

Thanks for the clarification. So, for measuring this voltage output while the device in sleep mode you should set the device to sleep mode as described in my previous reply.

Regards, Murugavel

0 Ali Khan 9 months ago in reply to Murugavel4637

Expert 1150 points

Hi Murugavel4637
This is what I did to put in sleep MODE

Power off the EVM.
Connect the MODE selection jumper short to GND - see below. This will set the device in PWM mode when it powers up.
Set both potentiometers in completely counter clockwise position.

Now this is I analyzed.

Voltage at R20 when not in sleep Mode is 0.2mV and supply total current to the board is 8mA
When board enters into sleep Mode then voltage at R20 is 0V and supply total current reduced to 5 to 6mA.

Now active mode current seems like 2 to 3mA of the driver part only but i can not verify still sleep mode current because it is very low and no voltage drop

+1 Murugavel4637 9 months ago in reply to Ali Khan

TI__Guru 55135 points

Hi Ali,

Ali Khan said:
Voltage at R20 when not in sleep Mode is 0.2mV and supply total current to the board is 8mA

When board enters into sleep Mode then voltage at R20 is 0V and supply total current reduced to 5 to 6mA.

Now active mode current seems like 2 to 3mA of the driver part only but i can not verify still sleep mode current because it is very low and no voltage drop

In active mode the voltage you were measuring across R20 without load connected would be primarily the device active mode current which would be 2-3 mA x 0.1 Ω = 0.2 to 0.3 mV, which is in-line with your voltage measured across R20 in active mode.
The 2-3 mA device active mode current you measured and calculated looks in line with the device specifications. With no load, per datasheet the active mode current would be 1.6 mA typical and 3.6 mA max. for this device.
Correct. In sleep mode, the current through R20 is expected to be 55 nA max. and 1 nA typical. This would be 0.1 Ω x 55E-09 = 5.5 nV max. and 0.1 nV typical, which is negligibly small you'd read almost zero. If you could measure 0.1 to 5.5 nV accurately with a nano voltmeter you may be able to measure these.

I do not see any problems with your measured results. They align with expected values. Let us know your concerns. If no concerns please close this thread by marking RESOLVED. Thank you.

Regards, Murugavel

0 Ali Khan 9 months ago in reply to Murugavel4637

Expert 1150 points

Yes, Everything is good.
Thanks for your help.
I really appreciate it.
I will resolve it now.

0 Murugavel4637 9 months ago in reply to Ali Khan

TI__Guru 55135 points

Thank you for the confirmation and closing.

Regards, Murugavel

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