Step down a 5V supply to a 3.3V supply using a BUCK converter IC to provide supply to a BLE IC

Thread Starter

anikseng

Joined Sep 28, 2022
29
Hello all,

I am using a BLE IC (CYBLE 416045-2) for a Bluetooth connection purpose and the IC works with a maximum power supply of 3.3V.

I am designing a PCB in which the power supply rail is 5V (which cannot be changed because of other devices, and this is the supply we have to use).

To supply power the BLE IC I want to use a BUCK converter IC to convert the 5V supply to a 3.3V supply. The BUCK converter IC that I am founding over the internet have a high continuous current supply like 1-2A like the one here AP61102.

My doubt is that with that much high current of 1-2A will it be able to drive the BLE IC?

Thanking you,
Anik Sengupta
 

ericgibbs

Joined Jan 29, 2010
19,114
hi Anik,
If the BLE device draws a lower current than the AP6110 maximum current specification, the BLE device will only draw the current it requires to operate.
Is this the question you are asking?
E
 

Ian0

Joined Aug 7, 2020
10,276
Don’t forget that a linear regulator would be 66% efficient for that job. Check the efficiency curves for the current you need for the BLE device. I don’t imagine it would be much (it‘s not called Bluetooth Low Energy for nothing). You might be wasting your time with a switching regulator.
 

LowQCab

Joined Nov 6, 2012
4,300
A Switching-Regulator is extreme over-kill.

Just put 3 generic-Silicon-Diodes in series, and a 100nf Ceramic-Capacitor,
on the Power-Input-Pins, and you're done.

The 3 Diodes in series will drop the 5-Volt-Rail down to ~2.9-Volts which
is right in the middle of the recommended Input-Voltages.
.
.
.
.
.
.
 

Ian0

Joined Aug 7, 2020
10,276
A Switching-Regulator is extreme over-kill.

Just put 3 generic-Silicon-Diodes in series, and a 100nf Ceramic-Capacitor,
on the Power-Input-Pins, and you're done.

The 3 Diodes in series will drop the 5-Volt-Rail down to ~2.9-Volts which
is right in the middle of the recommended Input-Voltages.
Red LED also might work. As a free bonus you get an indicator when the Bluetooth is using power.
 

ericgibbs

Joined Jan 29, 2010
19,114
hi,
We are working on the assumption that the 'BLE' is the only device being powered from the AP6 3.3v module.?

@anikseng Perhaps the TS could confirm what the full current load is for the AP6 output.?

E
 
Top