BQ24725A: BQ24725A

Hi Vivek, 

Thank you for reaching out!

Could you please provide more information on your battery charger design? 

1- Are you observing this behavior on an EVM?

2- What is the input voltage/current? 

3- Could you provide the schematics?

Best Regards, 

Aya Khedr 

Hi Aya,

Please find below Answers:-

1- Are you observing this behavior on an EVM?

--Same used EVM

2- What is the input voltage/current? 

--12V/3A,16/3A/19V/8A

3- Could you provide the schematics?

--Please find ref. Schematic.

Hi Vivek, 

I will review the schematic and get back to you with feedback by Thursday. 

Could you also provide the register map settings used?

Best Regards, 

Aya Khedr 

Hi Aya,

How to set register map please explain the Process or please give the support/setup as per below because we want to include  BQ24725A  ic in our product.

Input details are given below.

1. Adaptor Input voltage =12/3A

2. requirement for system =6 volt to 12 volt. 3Amp.

3. we wants to use 7.4 volt lithium polymer battery/Li-ion battery 

4. requirement of battery volt status on display/with our SOC

Note:- IC is detecting on i2c all parameters are meet as per data sheet but only desired output is not coming on battery terminal.

Regards,

Vivek

Hi Vivek, 

The BQ24725A is an SMBus controlled battery charger. The SDA and SCL pins should be connected to the SMBus data lines from the host controller. 

See section 8.5 Register maps for the setting charger options. There are 6 battery charger commands that are used to configure the charge current, charge voltage, and input current limits. 

See my comments below in regards to the schematic: 

1- I don't see any capacitance on the system (see below for example schematic from datasheet): 

2- Connect 10kOhm pull-up resistors on the SDA and SCL pins according to the SMBus specifications instead of 2.2kOhm (which you currently have)

Please let me know if you have additional questions/concerns. 

Best Regards, 

Aya Khedr 

Hi, Aya,

Understood which you have suggested but my problem is that how to configure the Commands in our software.

Please provide the full solution.

I have Added 220uf cap. at SYS as which you have suggested. 

All parameters are meets even SYS is also working on battery mode but my problem is that battery not getting charge due to under voltage. which will be sorted out by commands/driver.

I am waiting for your valuable recommendation  

Regards,

Vivek

Hi Aya,

We have successfully read Device ID and Manufacturing ID from BQ24725A using I2C source code, Now we need to get battery voltage % or backup.

So please let me know, how can I get using source, what command sets I need to implement into source code.

Regards,

Vivek Kumar

Hi,

I am waiting for your reply

Thanks & Regards,

Vivek Kumar

Hi Vivek, 

Could you please clarify which of the following commands below you are trying to read/write?

Best Regards, 

Aya Khedr 

Hi Aya,

I have tried last two commands (ManufactureID(), DeviceID), now i need to read voltage, Can you share the sample source code.

Regards,

Vivek Kumar

Hi Aya,

We are able to change the drive voltage and current and switch the voltage from  Vin to SYS and  to Battery voltage. but switching frequency is not coming on battery inductor.

please suggest.

Regards,

Vivek Kumar  

Hi Vivek, 

Could you please provide waveforms similar to those below?

(refer to Section 6.7 Typical Characteristics in datasheet)

Best Regards, 

Aya Khedr 

Hi Aya,

I will provide on Monday to understanding the issue.

Regards,

Vivek Kumar

Hi Vivek, 

Thank you for the update. Feel free to respond to this thread when you have more information.

Best Regards, 

Aya Khedr