Power section for VBAT & VDDIO of nRF7002

[Jagan K]

Hi,

  We are planning to move with the nRF5340 + nRF7002 for our upcoming project. We have some queries related to power section which are,

1. can we an use the same power source- LDO for VBAT & VDDIO(IOVDD) as 3.3V.

2. What is the current consumption for the IOVDD section?

3. We are planning to remove the suggested load switch for IOVDD section and add own circuit. do we need 1A load switch?

Thanks,

Jagan K

[Priyanka]

Hi Jagan,

1. can we an use the same power source- LDO for VBAT & VDDIO(IOVDD) as 3.3V.

Yes, this should be fine. If you take a look at the datasheet of the 5340, you can see that the VBAT operational range is between 1.7V to 3.6V and the VDDIO matches the voltage level of the VBAT. So using the same power source say, a single LDO can simplify your design. 

2. What is the current consumption for the IOVDD section?

This will depend greatly on the operational modes, your activity, the number of GPIOs used, etc. A GPIO pin can source/sink a maximum of around 15mA (but usually lower). In the sleep mode, the current draw will be in microamps and in active mode where you have a lot of GPIO pins toggling, the current consumption can range from micro to milli amps. But the exact consumption will depend on your use case.

3. We are planning to remove the suggested load switch for IOVDD section and add own circuit. do we need 1A load switch?

The load switches can help to manage the power to various sections of your circuit, separately and it's good practice to use a load switch with a higher capacity if your application has multiple GPIO pins driving high-current loads simultaneously. However, for the 5340 applications, the 1A could be a bit too much and maybe you could use something in the range of 300-500mA. But you can use 1A if you are powering other high-current peripherals via the IOVDD.

Regards,

Priyanka

[Jagan K]

Hi Priyanka,

   Thanks for your support.

   I believe that your answers are for the nRF7002 design, as i see you have mentioned nRF5340 in your statements.

   #3 And for nRf7002, as per the DK design the load switch TCK108AG,LF. We are planning to replace this part with MOSFET or other switch with low current design. is it advisable?

 

Thanks,

Jagan K

[Priyanka]

Hi Jagan,

Sorry for the confusion for the 1st question.

Yes, you can use the same power source for VBAT and VDDIO, it was for the 7002 design , not the 5340.

Jagan K said:

And for nRf7002, as per the DK design the load switch TCK108AG,LF. We are planning to replace this part with MOSFET or other switch with low current design. is it advisable?

As always, we recommend using the components that are used by us because we have only tested and hence can guarantee proper working, for these parts. But replacing the TCK108AG,LF load switch with a MOSFET or another low-current switch should be fine if you carefully match the specifications to your design requirements. Ensure the MOSFET or switch you choose can handle the voltage and current requirements, has a low on-resistance, appropriate gate threshold voltage, and adequate thermal performance. Though we cannot guarantee proper or exact working as this is something we have not tested.

-Priyanka