EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: bipolunipol on August 09, 2021, 08:48:46 am
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Hello,
I create a system powered by a LiPo battery. It will have an OLED SSD1306 128x32px I2C display and a microcontroller. And I wonder how this display could be powered. According to the documentation:
- Pin VDD (Power supply pin for core logic operation) should have a voltage of 1.65V to 3.3V. So I decided to use a 3V LDO stabilizer, which will lower the battery voltage (I assume the range of volatility: 3.2V-4.2V), which varies in a fairly wide range.
- The VBAT pin (Power Suppply for DD / DC converter) can have a voltage in the range of 3.5-4.2V. So I decided to power this voltage conventer directly from the battery. I know the battery voltage can go below 3.5V, but I checked it and the voltage conventer works fine for 2.8V, so it shouldn't be a problem here. (The internal converter generates a voltage of VCC = 7V to 15V).
So I designed a diagram like this bellow.
I added a Q1 transistor to connect the internal DC / DC converter to +3.6V (battery +). According to the documentation, the power should be connected first to Vdd, then to Vbat / Vcc (power to the OLED panel).
Now I wonder if this approach is right and is the circuit diagram correct?
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C1+C13 i think are overkill
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C1+C13 i think are overkill
I wanted to reduce the impedance of the resultant capacitor this way, but I will see without.
And is the power supply from 2 different voltages - voltage regulator (display logic) plus directly from the battery (converter in the display) is ok?