Regarding High Efficiency 5V Boost And 3A Li-Po Charge Controller

[sakibnaz]

Hi there.

I am working on a project which will be Li-Po 1-Cell Battery (6Ah) powered device. My project have ARM CPU hence it need 5V to run. For Battery Charging I like to implement USB Type-C 15W (5V, 3A) Charging system.

Now my device size needs to be small hence I am looking for if there any suitable High Efficiency 5V Boost Converter IC which integrated with 3A Charge Controller?

Initially I chooses TPS61232 Boost Converter (96% Efficiency) and there are many 3A Supported Switching Charge Controller which I can use. But if there any Boost Converter (High Efficiency and support around 2A) and Charge Controller (3A) Combo IC that will be best.

If anyone know ... please suggest.

Thanks in advance.

Regards.

 

[Audioguru]

You are making a common "Power Bank". I have one that is 16Ah and it is charged from 5V mini USB and delivers 5V to a ordinary USB connector.
Buy one on Black Friday when they are on sale again.

 

[sakibnaz]

Hi.

My project is not a Power Bank or similar thing .... its an IoT Device instead.

My device needs to be small in size hence I am looking for a combo solution of Switching Boost Converter and Charge Controller.

If anyone other can advise ... is highly appreciated.

Thanks.

Regards.

 

[Audioguru]

My project is not a Power Bank or similar thing.
I am looking for a combo solution of Switching Boost Converter and Charge Controller.

A power bank has a switching boost converter/voltage regulator at its output and a charge controller at its input. It might be made in a single IC.

 

[BradtheRad]

USB Type-C 15W (5V, 3A)

Did you already make sure you know how to get that much Amperes from your USB port? USB protocol only provides 100mA at first. Before a device is permitted to draw higher current it needs to communicate by a process called enumeration.

 

[sakibnaz]

Hi @BradtheRad.

The device Charging Port is USB-C which will connect to a USB-A Charger via USB-C to USB-A Cable. Charger can be something like the below:

Amazon.com: 5V/3A UL Certified Wall Charger Adapter: Automotive

Buy 5V/3A UL Certified Wall Charger Adapter: Wall Chargers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

So as per my understanding here I don't need any PD here. So in this case of USB-C to USB-A ... still enumeration needed? Is it something like PD Contract?

Thanks.

 

[yagizhanugur]

If you are talking about USB port on a computer, You still cannot provide 3A from a USB port even if you enumarete it. It is probably limited with max 500mA. If you are designing a USB client with which needs to enumareting the host you can use FT231X. It can tell you which type of USB host that you re connected so you can limit your charge current before the host blocks it. But still 3A is too much for a computer.if you re planning to plug your device to a dummy port there is no current limit.

Let's talk about IC. Why didn't you look texas BQ series. They have very wide range products. I bet you can find what you need.

 

[BradtheRad]

So as per my understanding here I don't need any PD here. So in this case of USB-C to USB-A ... still enumeration needed? Is it something like PD Contract?

Sorry, it takes someone with more up-to-date experience than me who could answer your questions.

I see that USB-C offers improvements with data and Power Delivery (PD). The link below has this caution:

Just because a device or cable supports USB-C does necessarily mean it also supports USB PD. So, you’ll need to make sure that the devices and cables you buy support both USB-C and USB PD.

https://www.howtogeek.com/211843/usb-type-c-explained-what-it-is-and-why-youll-want-it/

 

[sakibnaz]

Hi @yagizhanugur.

Generally my device will,not be connect to a PC to get charged. But yes if its connected then it can get Charge current of 500mA which is the max limit if PC USB-A port.

I'll provide to user dedicated Wall-Charger (USB-A, 5V, 3A) like the below:

Amazon.com: 5V/3A UL Certified Wall Charger Adapter: Automotive

Buy 5V/3A UL Certified Wall Charger Adapter: Wall Chargers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

I don't wanted to make the charging system complicated. I want a simple charger which supports 3A max ... so if the device connected with the Wall-Charger then charge current can be 3A or close to. If device connected to any other charger supports less Amp then charge current will be less Amp.

So in my case do I still need any enumeration? Can you advise any suitable Charging IC (Supports 3A)?

Regards.

 

[yagizhanugur]

Hi @yagizhanugur.

Generally my device will,not be connect to a PC to get charged. But yes if its connected then it can get Charge current of 500mA which is the max limit if PC USB-A port.

I'll provide to user dedicated Wall-Charger (USB-A, 5V, 3A) like the below:

Amazon.com: 5V/3A UL Certified Wall Charger Adapter: Automotive

Buy 5V/3A UL Certified Wall Charger Adapter: Wall Chargers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

I don't wanted to make the charging system complicated. I want a simple charger which supports 3A max ... so if the device connected with the Wall-Charger then charge current can be 3A or close to. If device connected to any other charger supports less Amp then charge current will be less Amp.

So in my case do I still need any enumeration? Can you advise any suitable Charging IC (Supports 3A)?

Regards.

I suggest you to use sepearate Bosst converter IC and charger ic .

for charge you can use :

https://www.ti.com/lit/ds/symlink/bq24296m.pdf?HQS=TI-null-null-digikeymode-df-pf-null-wwe&ts=1598435948432

It has USB Host Detection feature. It will limit the current as well. And another important point is power path management and Battery Protection. You need to select the path when your device connected to charger.

It is really hard to find with all features in same ic.

Regards.

 

[sakibnaz]

Ok noted.

Yes I am also thinking to use Boost and Charge separate. May be for boost I'll use TPS61236

Some ques please:

- In BQ24296M ... USB OTG with Adjustable output (SYS voltage): I don't need this right ... so just leave this section open?

- I2C control looks a bit complex to me ... how is MP2636 compare to BQ24296M?

Thanks.

 

[yagizhanugur]

Ok noted.

Yes I am also thinking to use Boost and Charge separate. May be for boost I'll use TPS61236

Some ques please:

- In BQ24296M ... USB OTG with Adjustable output (SYS voltage): I don't need this right ... so just leave this section open?

- I2C control looks a bit complex to me ... how is MP2636 compare to BQ24296M?

Thanks.

Hello

USB OTG does not required for your project. It is about the communication without a USB Host like PC.


MP2636 looks good for me.


Regards.

 

[BradtheRad]

It looks as though you want to charge a 5V battery from a 5V supply.
Here's a simple charge pump which might do the job. It's a voltage doubler. Output voltage can never go higher than 2X supply V, regardless whether a load is attached. (Whereas a boost converter with no load is liable to create spikes and/or soar to extreme volt levels, unless control circuity shuts off operation.)

The above schematic is the raw concept. Experiment with values to find a suitable charge rate. It also depends on what amount of current you're able to draw. You need to install control circuity so as to shut off charging. However it might be possible to limit voltage (say, with a zener diode in a control position) to 5.5V or 6V or some safe level. Then it causes charging to end automatically.

 

[Audioguru]

A lithium cell is an explosive/fire hazard if it is charged to more than 4.20V.
When the cell voltage has reached 4.20V then it is about 70% fully charged and is still changing and needs more charging time until its charging current drops to a low amount then the charging should be stopped..