LDO and I2C sensor powered directly from the GPIO
Posted: Sat Feb 16, 2019 5:32 pm
Hi,
My I2C sensor operates at 2.8 V, therefore I need to add the LDO to get from 3.3 V down to 2.8 V. And the I2C sensor requires max 2 mA for operation. GPIO from esp32 can supply up to 40 mA.
I would like to avoid having LDO powered when I don't need the sensor in order to minimize the current.
Therefore I would like to use the GPIO from the esp32 to power the LDO directly. So when GPIO is 0, neither LDO nor sensor will consume any current.
1. Can I do that? Is this ok practice?
2. For LDO to work I need to put 1 uF capacitor between the Vin, GND (as in the attached schematics). What will happen when I set GPIO to 0? Will the capacitor discharge problematic?
Attached screenshot of how to connect the LDO - Vin would be connected to GPIO from esp32, Vout is Vdd for I2C sensor.
Thanks so much!
My I2C sensor operates at 2.8 V, therefore I need to add the LDO to get from 3.3 V down to 2.8 V. And the I2C sensor requires max 2 mA for operation. GPIO from esp32 can supply up to 40 mA.
I would like to avoid having LDO powered when I don't need the sensor in order to minimize the current.
Therefore I would like to use the GPIO from the esp32 to power the LDO directly. So when GPIO is 0, neither LDO nor sensor will consume any current.
1. Can I do that? Is this ok practice?
2. For LDO to work I need to put 1 uF capacitor between the Vin, GND (as in the attached schematics). What will happen when I set GPIO to 0? Will the capacitor discharge problematic?
Attached screenshot of how to connect the LDO - Vin would be connected to GPIO from esp32, Vout is Vdd for I2C sensor.
Thanks so much!
- Screenshot 2019-02-16 at 18.09.17.png (53.51 KiB) Viewed 4266 times