WEBENCH® Tools/TIDA-010030: BQ76940

furkan khan

Part Number: TIDA-010030
Other Parts Discussed in Thread: BQ76940, BQ78350-R1, BQ34Z100-G1, TIDA-01093, ISO1541, ISO1540, MSP430FR2155, TCAN4550-Q1

Tool/software: WEBENCH® Design Tools

Dear TI Team,

1. how to control charging current in TIDA-010030.

2. When system off low voltage shutdown (DISGH. MOSFET OFF). then connect charger so how to ON both mosfet chg. discg.

3. ho w to set low cut recovery voltage.

4. How to implement auto load sense.

5. How to implement ship mode, sleep , and auto mode and condition also.

over 5 years ago

0 Matt Sunna over 5 years ago

TI__Guru* 80963 points

Hi Furkan,

Each of these items needs to be controlled by the MCU. We are not able to advise on the MCU coding unfortunately. I will loop in the engineer who developed this reference design to see if he can provide any assistance, but I do not think there is sample code available for this design.

Another option (if you are not comfortable developing the code) is to use the BQ78350-R1 controller that includes a battery gauge. The BQ78350-R1 comes equipped with firmware specifically for working with the BQ76940 device. It can work with a smart charger, control the FETs, handle all protections and recovery, and control ship/sleep modes. You can reference this TI design as an example: http://www.ti.com/tool/TIDA-00792

Best regards,

Matt

0 furkan khan over 5 years ago in reply to Matt Sunna

Intellectual 365 points

Hi Matt,

Actually i am workin on this project. So please if you have some suggestion share with me.

0 Ryan Tan over 5 years ago in reply to furkan khan

TI__Expert 3345 points

hi, regarding your questions:

1. the charging current is controlled by the charger, which is not included in TIDA-010030.

2. TIDA-010030 has charger wake-up circuit which can output a high level pulse on TS1 of bq76940 and wake it up, then you can use I2C command to turn the charge and discharge MOSFET on.

3. low recovery voltage is set in MCU firmware. but if the system enters ship mode, the system can't recovery except charger plugged.

4. if you are using bq76940 to control low side charge and discharge FET, the CHG pin can detect load. if you are using TIDA-010030 similar architecture, the the load detect is processed by MCU firmware.

5. ship mode: 1, battery pack cell voltage is too low; 2, battery pack is first time powered on. standby mode: there is no charger or resistive load, it is in standby mode and detecting charger or load. actually it depends your actual requests and is all firmware work.

Best Regards,

Ryan

0 furkan khan over 5 years ago in reply to Ryan Tan

Intellectual 365 points

hi,

how to control temp. and how to declare over temp. We took some reference of software but not working. So please suggest how to measure and control.

0 Ryan Tan over 5 years ago in reply to furkan khan

TI__Expert 3345 points

Hi,

TIDA-010030 uses bq76940 to measure pack temperature through 3 thermistors and compares with the reference set in the firmware. And if the data is too high or too low, MCU will control bq76940 to shutdown MOSFET through I2C commands.

You can refer below sample code to read data from bq76940, including the temperature information.

http://www.ti.com/general/docs/lit/getliterature.tsp?baseLiteratureNumber=SLUC583&fileType=zip

0 furkan khan over 5 years ago in reply to Ryan Tan

Intellectual 365 points

hi,

1. how to implement SOC and SOH logic . I am using gauge IC bq34z100pwr-g1

0 Ryan Tan over 5 years ago in reply to furkan khan

TI__Expert 3345 points

hi,

The SoC and SoH data are calculated by bq34z100-g1. It works alone and doesn't need firmware to control. So TIDA-010030 just read data from bq34z100-g1.

If you want to know how bq34z100-g1 works, below document might help, it explain how IT gauging algorithm works.

http://www.ti.com/lit/an/slua450/slua450.pdf

If you need more infomaiton, i suggest you to create a brand new E2E question about bq34z100-g1 only. That will be more effective.

thank you.

Best Regards,

Ryan

0 furkan khan over 5 years ago in reply to Ryan Tan

Intellectual 365 points

Hi TI team,

Thanks for your support. one module has been made. Now i am working for series and parallel module for increase rating in form of voltage and current. so please check my roughly schematic of power . it is ok ?

0 Ryan Tan over 5 years ago in reply to furkan khan

TI__Expert 3345 points

hi,

I am not sure if 2 pieces BQ76940 can be connected with transformer, the communication is I2C.

And bq76940 is a 9-15s AEF, which might be over design for a 12V BMS. I have looped in our application engineer, he might have more comments.

Best Regards,

Ryan

0 furkan khan over 5 years ago in reply to Ryan Tan

Intellectual 365 points

hi ,

actually this is for 13 cell. please revert as soon as possible . may i use 2 BMS with isolated communication and control by master card.

0 Ryan Tan over 5 years ago in reply to furkan khan

TI__Expert 3345 points

hi,

yes, you can use isolated I2C and connect two bq76940 to one MCU. please refer TIDA-01093.

http://www.ti.com/tool/TIDA-01093

Best Regards,

Ryan

0 furkan khan over 5 years ago in reply to furkan khan

Intellectual 365 points

Hi Ryan,

please suggest I2C to CAN converter IC for stackble bq76940

0 Ryan Tan over 5 years ago in reply to furkan khan

TI__Expert 3345 points

hi,

if you only need to use MCU to communicate with two stacked bq76940, isolated I2C device is good enough.

you can refer ISO1540 and ISO1541.

And bq76940 doesn't support CAN communication.

Best Regards,

Ryan

0 furkan khan over 5 years ago in reply to furkan khan

Intellectual 365 points

Hi,

Ryan

1. If i am not using srp , srn and CHG, DSG pin in bq76940(TIDA-010030). may i connect these pins with ground ?.

2. In TIDA-010030 CAN Communication is possible. if yes do you have any CAN communication code.

0 Ryan Tan over 5 years ago in reply to furkan khan

TI__Expert 3345 points

Hi Furkan,

1. Recommend to short SRP and SRN to GND. While if short DSG and CHG pin to GND, please make sure that these MOSFET drivers are disabled.

2. MSP430FR2155 doesn't support CAN communication, so TIDA-010030 only gives a recommended isolated CAN transceiver.

Best Regards,

Ryan

0 furkan khan over 5 years ago in reply to Ryan Tan

Intellectual 365 points

Hi Ryan,

There is possible CAN communication ?. in TIDA-010030 CAN communication is available.As you say that CAN communication is not supported so why use CAN transceiver in TIDA-010030. ?.

0 Ryan Tan over 5 years ago in reply to furkan khan

TI__Expert 3345 points

Hi Furkan,

It is possible to use firmware to simulate CAN communication, but also very hard to achieve this. If CAN is necessary in your design, you may change your MCU or build more code to simulate CAN. Anyway CAN transceiver is required.

Also I know that TI has CAN controller: TCAN4550-Q1. Just for your reference.

Best Regards,

Ryan

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WEBENCH® Tools/TIDA-010030: BQ76940

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