Author Topic: TE00724 - How to set a different VLDO34 voltage in PMIC  (Read 153 times)

monica

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TE00724 - How to set a different VLDO34 voltage in PMIC
« on: January 18, 2021, 08:37:57 PM »
Hi everyone,
I'm developing a carrier card for Trenz SOM TE0724. This SOM has a power management IC (DA9062) that controls the power-on sequencing and provides different on-board voltages. I would like to use the outputs of VLDO2 (1.8A/300mA) and VLDO34 (2.5V/600mA) to have a joint 1.8V/900mA power source. As the output voltage of these LDOs can be programmed via I2C, it shouldn't be a problem as log as I can delay the VLDO34 power-up until after the internal registers have been reconfigured. So I need to:
power-up Bucks, LDO1 and LDO2 in PMIC -> reconfigure VLDO34 voltage via I2C -> power-up VLDO34 as a 1.8V source
Is this possible?

According to DA9062 datasheet, it should be possible to use inputs PWR_GPIO2 and PWR_GPIO4 to change the power-up sequencing in DA9062 but I'm having the same results whether I set these inputs as '0' or '1': all output voltages are powered-up according to the sequence shown in TE0724 TRM, so VLDO34 is 2.5V before I can reconfigure it to be 1.8V. These tests were performed using Trenz carrier TEB0724. I would appreciate your help on this.

Martin R.

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Re: TE00724 - How to set a different VLDO34 voltage in PMIC
« Reply #1 on: January 20, 2021, 06:33:01 PM »
Hi Monica,
the OTP of the PMIC is preprogrammed. In the configuration we use the LDOs are controlled by the sequenzer and not by GPIs.
Furthermore to have the I2C bus of the zynq working you have to power up completly before you can configure something via I2C to the PMIC.
We do not have any experience with reconfiguring during operation for this device.
If you are thinking about a series product, a customer specific PMIC firmware could be an option.