Best Regulator for Li-Ion Battery

[wat007]

Hi,

I am planning to use Single Li-ion for my board with MCU and other ICs. Li-ion voltage range is from 3.0V to 4.2V. Since some of my ICs' supply voltage should not exceed 3.6V, i am planning two regulate the voltage to at least 3.0V.

My questions are:
1. What is the minimum input voltage if I will be using 3.0V zener diode?
2. Any suggestion for low-drop voltage regulator?

Thanks in advance.

 

[KlausST]

Hi,

1. What is the minimum input voltage if I will be using 3.0V zener diode?

We can´t give an answer without circuit. At least: series resistor, diode voltage, min/max load current, min/max output voltage

2. Any suggestion for low-drop voltage regulator?

We can´t give an answer without more informations...


Klaus

 

[Audioguru]

A low voltage zener diode is a poor voltage regulator because its voltage changes with load current and with temperature changes.
A zener diode wastes battery current all the time.
Instead you should use a low dropout linear voltage regulator IC. The one I use is not made anymore but I still have some to use for my projects.
Do you have a circuit that will disconnect the battery from its load when its voltage drops below about 3.2V? If you don't then the battery cell will be destroyed and might catch on fire if it is charged.

 

[wat007]

Hi KlausST, I will give post drawing when available. Regulated supply should power MCU and 2-3 more ICs (probably around 100mA, Iout).

- - - Updated - - -

Hi Audioguru, I'll go with LDO and planning to use LD6836TD/30H.

In disconnecting battery,can schmitt tigger do the job? I want to make it simple as possible.
Would you mind sharing your circuit?

Thanks!

 

[Audioguru]

A Schmitt trigger has an output that switches high or low. It will not disconnect the load from the battery but it can sense the battery voltage and switch a Mosfet to disconnect the load away from the battery.

 

[wat007]

@Audioguru, that is an option.

Any other ways? Thanks

 

[ernpao]

Have you had a look at power management specific solutions? A device designed for battery powered applications is probably the simplest solution you can get. I think microchip's MCP73871 could work for you, https://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en536670&redirects=MCP73871

 

[wat007]

Have you had a look at power management specific solutions? A device designed for battery powered applications is probably the simplest solution you can get. I think microchip's MCP73871 could work for you, https://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en536670&redirects=MCP73871

yes, but it so expensive for my product. I am designing a simple toy so discrete or simple component should be my first option.

 

[Audioguru]

There are many inexpensive remote controlled (using infrared) toy helicopters that use a custom remote control IC that correctly charges a Lithium battery and disconnects the load when the battery voltage becomes low.