Configuring BQ25190 Buck Converter for 3.3V Default Output Without I²C for ESP32-S3-WROOM-1

morris webb

Part Number: BQ25190

Tool/software:

I'm designing a PCB to power an ESP32-S3-WROOM-1 (3.3V, 500mA peak) using the BQ25190.

I need to supply 3.3v to the ESP32 and need to configure the BQ25190 to supply this voltage, specified during PCB layout, to avoid initial i2c programming.

The datasheet doesn't specify a default BKOUT voltage. Is there a way to configure BKOUT for 3.3V using external components (e.g., resistors) or other hardware means?

If not, are there any default voltages compatible within the input range of the microcontroller between 3.0 and 3.6v (with a peak of 500mA)?

In fact, do you have any advice?

2 months ago

0 morris webb 2 months ago

Prodigy 20 points

as an addendum - ultimately i would prefer to use the full range of a lipo battery's usable voltage to supply power and so would have been interested in the buck-boost as well.

I get the impression i need to use a small 5v tolerant microcontroller to manage connected to SYS, which will send the initial configuration via i2c for setting up the power rails I need - 3.3v first for the espressif part, then followed by 2.8v and 1.5v for the attached camera when it's required.

0 morris webb 2 months ago

Prodigy 20 points

I should note: I have read through the response in another thread https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1484104/bq25190-register-setting-initialization-issue-in-bq25190/5701768#5701768 and the part that was still unclear to me is if BUCK_VOUT needs to be specified through i2c before it will do any regulation on any regulator @ 3.3v - datasheet seems to say it's i2c specified.

feels like a chicken and the egg problem

0 Juan Ospina 2 months ago in reply to morris webb

TI__Genius 17505 points

Hi,

As mentioned in that thread the default BUCK output voltage is resistor configurable as indicated by the table. This wouldn't require any I2C communication to regulate since it works using default register values.

The default BUBO voltage is 4.8V, this would require I2C communication to change the regulation set point after each POR. LDO1 and LDO2 have default 1.8V and off voltages respectively.

Best Regards,

Juan Ospina

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Configuring BQ25190 Buck Converter for 3.3V Default Output Without I²C for ESP32-S3-WROOM-1