LiPo Power Rails - Githubissues

digitaldanny / AudioEffectsGlove

A hand tracking glove that controls parameters of various audio effects.

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LiPo Power Rails #45

Closed digitaldanny closed 3 years ago

digitaldanny commented 3 years ago

Describe the solution you'd like Create a 3.3V power rail for the glove PCB, powered with the 3.7V Li-Po battery.

Find a buck/boost converter that will allow a single cell Li-Po battery to power the glove hardware from 3.7V down to 3.0V (the full battery life).
What is the DC-DC circuit for on the VCORE and VSW pins in the MSP432 schematic pg. 36?

Describe alternatives you've considered Was originally planning to use a 3.3V linear voltage regulator, but I realized that the voltage dropout was too high (~300 mV). This would mean that the battery could only power the circuit from 3.7-3.6V.

Additional context TPS63020 Buck/Boost Converter will allow use of the battery from 3.7V down to 3.0V.

digitaldanny commented 3 years ago

Using the TPS63020DSJT set to output 3.3V. I have added a header that will need to be shorted in order to make the buck/boost converter the 3.3V power rail for this system. This will be useful for debugging because I can make the DAD board the power supply while debugging board issues.

digitaldanny commented 3 years ago

In order to estimate the battery's Open Circuit Voltage (OCV), the microcontroller needs to be able to power other hardware on/off. My solution to this is to include a P-channel power MOSFET that supplies the buck/boost output voltage to the rest of the circuit. The FET gate can be toggled with a uC GPIO pin.

When the uC powers off the rest of the hardware, only the MSP432 and the TPS63020 buck/boost converter will be using the battery voltage. I believe this is about as close to OCV that I can get while still having my microcontroller running.

Right now, I am using a 4P03L04 for this purpose.

digitaldanny commented 3 years ago

Added in a high power MOSFET where the output is the source of the glove's 3.3V power rail. The gate can be controlled by an MSP432 GPIO to enable/disable power from the rest of the circuit.