Regarding external power supply

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Regarding external power supply [Copy link]

 

I bought a circuit board with only one micro power connector. I want to use a battery (3.6V) for power supply. I can add a set of pin headers, and then connect the positive and negative poles of the battery to the pin headers through wires, and then connect them to the VCC network after passing through a voltage regulator chip. I would like to ask if this is the way to power it?

qwqwqw2088

Connect VCC after the voltage regulator chip, it is OK

宋元浩

LDO has voltage drop requirements, and it is estimated that it cannot stabilize voltage below 3.6V.

lehuijie

It depends on your voltage regulator vout. If the output is 3.3v, the maximum battery voltage is 3.6v. It is not recommended. The 6206 manual states that the maximum drop voltage of 3.3v output is 0.28v.

lehuijie

If the battery minimum value is 3.6v, or the output voltage is less than 3.3v, you can

well_kim

Boost to 5V and connect to USB_Vbus

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lehuijie posted on 2020-7-22 23:16 It depends on your voltage regulator vout. If the output is 3.3v and the maximum battery is 3.6v, it is not recommended. The 6206 manual states that the maximum drop voltage of 3.3v output is 0. ...

If the output is 3.3V, shouldn't the input be between 3.6 and 8V?

乐乐老了

lehuijie posted on 2020-7-22 23:17 If the minimum value of the battery is 3.6v, or the output voltage is less than 3.3v, it is possible

The minimum battery is only 2V. If two batteries are connected in series as above, can it be achieved? Also, if a 10,000mah battery is sufficient, do I need two 5,000mah batteries in series, or do I still need 10,000?

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well_kim posted on 2020-7-23 08:50 Boost to 5V and connect to USB_Vbus

Makes sense, I actually forgot I could boost the voltage

乐乐老了

well_kim posted on 2020-7-23 08:50 Boost to 5V and connect to USB_Vbus

Brother, do you have any recommended boost chip?

乐乐老了

well_kim posted on 2020-7-23 08:50 Boost to 5V and connect to USB_Vbus

First boost to 5V, then reduce to 3.3V, how much power will be lost in the process?

dcexpert

When powered by a lithium battery, it is possible to use a low voltage dropout LDO such as XC6206, and no boost is required.

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dcexpert posted on 2020-7-23 10:47 It is possible to use a low voltage dropout LDO such as XC6206 for lithium battery power supply, and no boost is required.

I searched online and found that the er26500 disposable lithium battery has a maximum voltage of 3.6, the end discharge voltage is 2V, the circuit is 3.3V, and the USB is 5V and the voltage is reduced to 3.3 through the step-down chip. Now I want to have a disposable lithium battery that starts discharging at 4.2V, but I can't find it. If I use this 3.6V, I can only step up or step down in series.

dcexpert

LeLeLao posted on 2020-7-23 11:05 I searched online and found that the er26500 disposable lithium battery I have is up to 3.6, the termination discharge is 2V, the circuit is 3.3V, and the USB is 5V after step-down...

When using a rechargeable lithium battery with a voltage range of 2.7-4.2V, there is no need to boost the voltage.