CYW943907 - Vbat, Vddio and power consumption

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KeBe_3995361
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Hello support,

I have a doubt related to Vbat and Vddio:

   - What is the purpose of Vbat? And the purpose of Vddio?

   - What is the difference between them?

I've done the measurements of power consumption according to Low Power Current Measurements Using CYW943907AEVAL1F​, but the lowest power consumption I obtained/measured was 30.7uA (on Hibernation, with attached hibernation.c). Is this correct? According to datasheet it has to consume 3uA when Hibernation...

pastedImage_8.png

Additional doubt

Furthermore, I would like to know if the current consumption measurements have necessarily to be done as it is specified on  Low Power Current Measurements Using CYW943907AEVAL1F​. If so, then, what is the purpose of the following pins?:

pastedImage_7.png

Thanks in advance,

Kepa

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Hi :

   just check the circuit , the sflash VCC is supplied by wlan_vddio , so the standby current is calculated into wlan consume also ,  I copy the spec here,  seems the additional current is from here .

pastedImage_0.png

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Zhengbao_Zhang
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Hello:

   I see the first volume shows "radio off "  ,  it means REG_ON is low or the device is in hibernation, and all supplies are present .

  and found below info:

pastedImage_1.png

so please add call before going to hibernation:

wicd_result_t wiced_wifi_down(void)

To see if the current can be decreased.

Actually the "radio off " is not used in most user cases because we always want to wifi to be in a ready and stable status.

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Zhengbao_Zhang
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checked again, we have a release document which describes the power mode in detail.

The name is WICED-Powersave-App-Note.pdf  , you can have a check with that.

pastedImage_0.png

by the way would you please help to measure the vio/vbat separately ,  I need to know the 30uA is from which power domain .

Hi, I measured both currents (I_bat and I_ddio) with wiced_result_t wiced_wifi_down(void) function added to original code.

The measured hibernation current was:

  • I_bat = 13.7uA
  • I_ddio = 16.7uA

So the total is 30.4uA.

I'm measuring the current in the following way:

I_bat

- At first, when the CYW943907AEVAL1F is initializing (until it goes to hibernate) the switch is in the position that is described in the following image:

pastedImage_2.png

- Then, when it goes to hibernate (low power mode), I change the switch position to measure the low current with a precision multimeter. The measured current on hibernation is 13.7uA, as mentioned above.

I_ddio

- At first, when the CYW943907AEVAL1F is initializing (until it goes to hibernate) the switch is in the position that is described in the following image:

pastedImage_6.png

- Then, when it goes to hibernate (low power mode), I change the switch position to measure the low current with a precision multimeter. The measured current on hibernation is 16.7uA, as mentioned above.

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thanks a lot for the details , I will have a try in my side .

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Hi :

   just check the circuit , the sflash VCC is supplied by wlan_vddio , so the standby current is calculated into wlan consume also ,  I copy the spec here,  seems the additional current is from here .

pastedImage_0.png

Hi support,

OK, so I have to substract the sflash current to get the true power consumption value... But, what value do I have to use in the substraction? If I substract 10uA (the typical consumption for SFLASH) then the total power consumption is: 30.4uA - 10uA = ~20uA.

However, the theoric Hibernation consumption value is 6uA... so, how I can get and verify with my board that the value in datasheet is correct?  Do I have to substract another value instead of 10uA?

(I'm assuming that the hibernation.c application developed by Cypress is designed to obtain 6uA value)

Moreover, Low Power Current Measurements Using CYW943907AEVAL1F should add your answer as note for measurements.

Thanks for the support!

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Hi ZhengbaoZ_96,

OK, so I have to substract the sflash current to get the true power consumption value... But, what value do I have to use in the substraction? If I substract 10uA (the typical consumption for SFLASH) then the total power consumption is: 30.4uA - 10uA = ~20uA.

However, the theoric Hibernation consumption value is 6uA... so, how I can get and verify with my board that the value in datasheet is correct?  Do I have to substract another value instead of 10uA?

(I'm assuming that the hibernation.c application developed by Cypress is designed to obtain 6uA value)

Moreover, Low Power Current Measurements Using CYW943907AEVAL1F should add your answer as note for measurements.

Thanks for the support!

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Sorry ZhengbaoZ_96​ , (or any other in the support...)

Can you answer my last question?

Thanks in advance

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hello:

so, how I can get and verify with my board that the value in datasheet is correct?

for this question , will do more tests on 43907AEVAL1F board,  to see if I can get close to the value.

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hello:

I just have a compare about the voltage supply between WCD2 evb and AEVAL1F  evb .

There supply network is different , so the result shows different ,I think this is a normal behavior.

please have a check in the attached.

Ok, thanks for the answer!

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Hello ZhengbaoZ_96

It's been a long time since you last answer, but just to be clear, do you mean that CYW43907 consumes 6uA when hibernate?

Or with the last answer you mean that the real consumtion is 20uA?

I need to know if those 20uA are because of the ev. board (as you mentioned that WCD2 evb and AEVAL1F power supply are different) or are going to be the real consumption that I will obtain with the chip.

These last weeks I've been comparing some 5GHz WiFi chips and this one has quite good results. The only negative point that it has is that it consumes 20uA. If you guys can ensure me that the datasheet's 6uA are correct then this component satisfies my project requirements.

Regards,

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Hello:

     Actually I got the data from the application notes also,  so if your project is very critical for this hibernation current consuming on the pin Vbat+VIO, it is better to do below steps:

1.  confirm which module you will used,   normally , our module maker also has very strong support for the detailed board hardware testing.

2.  after the data is confirmed in module side,  ask help for the review in detail.

Concurrently, I am applying for a 943907WCD2 board for a current test on hibernation mode .

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Now answer another question, for this pic:

pastedImage_0.png

the module current test 10v-1A , this is a current-sense amplifier, we can get the current by calculating the result with a formula like below:

Vout = (GAIN)(Rsense)(I_Load)

Now the GAIN =50, Rsense in the board equals 0.2 Ω, we can get the results by just testing  this voltage.

but seems it is not linear when the current is in uA status .