ADP2503 - Over Current consumption

Hi Moulika,

I assume that your question is why input current measured is higher than what you see as Quiescent Current (VIN) in datasheet. This is because the what you have is not same as that specified in datasheet. Datasheet quiescent current is measured when the device is Enabled but not switching. I don't think the datasheet has specified the parameter that you are looking for when device is Enabled and switching to regulate the output. It is normal to see that input current when device is switching is much higher than Quiescent Current (VIN) in datasheet because of losses like the switching devices.

Hello,

do reduce current consumption in a no or low load scenario you should tie SYNC pin to GND, which enables PSM mode at lower loads. This should bring current consumption down significantly

Hi,

Thanks for the replies!

In our application, DC-DC has to power BLE module. When we operate in PSM mode then BLE is getting disconnected frequently.

Can you please suggest me on circuit so that in PSM mode, BLE will not get disconnected?

Below is our circuit  implementation:

If any modification required for this circuit, please suggest me.

Thanks,

Moulika.

Hi Moulika,

Your schematic will always have the operation in forced PWM as SYNC pin is tied to PVIN. So I assume this schematic does not have issue because this scheme won't have converter go into PSM. Am I correct?

If you confirm that you changed schematic to tie SYNC pin to GND and see the issue as opposed to SYNC pin tied to PVIN, then issue may be related to the PSM mode. When in this schematic (SYNC pin to GND), can you check if issue will disappear if output load is increased to when operation goes into PWM? Issue may likely be related to noise frequency harmonics introduced by PSM when operating at lighter load. You may want to consider using RF shield to fight against radiated emissions or LDO at output or filter for conducted noise emissions.

Figures 7 versus 8 are important to compare which efficiency you want to achieve. The advantage of using Normal Operation or PSM mode (SYNC pin to GND) is at output currents less than about 30mA where you see a big difference in efficiency over Forced PWM mode.