LM5060: If this can be used as a battery protector

Hi Bhanu,

If I understand correctly, your power path is Battery--> LM5060  --> DC stepper Motor. LM5060 can do the job of protecting the load from input voltage and Inrush current control during startup. This device can also protect the load and battery from short circuit at load. I wonder why you need Over voltage protection when the input is a Battery  ? Is there inductance in the path between battery and load ?

The next question you have is if this device allows for bidirectional flow of power to also charge the battery. LM5060 is not recommended to be used for bi-directional current flow  because when the FET is OFF the GATE pull down circuit will discharge the output cap through the internal Zener between OUT-GATE as shown in figure 32. 

While the Battery is being charged, do you just need the controller to turn ON the FETs or do you also need any kind of protection in this path ?

Hello Praveen,

I would like to use LM5060 to protect the IC from overvoltage.

The connection setup would be Battery-->BQ34Z100EVM.I would be connecting a load and charger parallelly to the battery. So in the event of any overvoltage or overcurrent the LM5060 can act as a protector. 

So if bidirectional flow is not possible can I just use LM5060 to protect the IC

Also would you recommend any other protectors which I could use for this purpose 

Thanks

Hi Bhanu,

Thanks for providing the information. Below is my understanding, please correct me if I am wrong.

1. You are trying to have a single protection circuit for both battery charging and discharging as shown below.
2. When the battery is being charged from Charger, you want OV protection. You do not need OC protection (probably the battery charger circuit is integrated in the battery pack).
3. When the battery is discharging/supplying the load, you need only OC protection. You do not need OV protection here because the voltage from the battery is pretty stable. 

Hello Praveen,

I do not require any protection during charging as the Charging circuit has protection built into it.

I require OV and OC protection during discharging. The reason I am looking for both is that 

previously we were using LTC2944 to find the SOC of the battery. But the LTC2944 IC kept getting damaged when the battery was connected.

So we figured out that OV or OC from the battery might be responsible for this.

So we have designed a new battery SOC indicator using BQ34Z100. To protect this IC I require a fast protector which will save the IC and its circuitry in the event of OV or OC.

Thanks

Hi Bhanu,

Got it now. Thanks!

LM5060 does not have accurate overccurrent protection. LM5060 is only recommended for output short circuit protection where the over current threshold need not be accurate. But if the short circuit protection in LM5060 is okay for you, you can use this device to drive 2 FETs connected back to back in common source configuration with the OUT pin of the controller connected to the common source point 

If more accurate current limit is required, I would recommend using LM5069 in same configuration as shown above.

If faster switching and more features are required, I would recommend using TPS48111-Q1 in the configuration  same as in TPS48111Q1EVM as shown below with the pre-charge path disabled. 

Hello Praveen,

Currently TPS4811-Q1,LM5069 are out of stock. Could you suggest any alternatives which can be used 

Thanks

Hello Praveen,

In the datasheet for LM5069 the application of  Battery Management System or UPS is not mentioned. So will LM5069 do a reliable job of protecting in case of OV and OC fast enough to protect the BQ34Z100 IC used in the EVM board

Also how about TPS 1663 this is a eFuse. Can I use this?

Thanks

Hello Praveen,

Thank you for the clarification. Is there any design calculator available for LM5069 to help me in designing.

Thanks 

Hi Bhanu,

Yes, you will find the design calculator in the device product folder. Please find the link below.

https://www.ti.com/product/LM5069#design-development 

Hello Praveen,

Thank you for the help

Could you help me out by reviewing my design

 /cfs-file/__key/communityserver-discussions-components-files/196/60C_5F00_temp.xlsx

Also I have 5 questions

1) In the current limiter section what do you mean by minimum, typical, maximum current limit.

2) In startup section the startup time is 114.00 ms but the fault timeout is 0.47 ms. In the video it was mentioned that this would affect the device.

    Could you kindly check the design and let me know if there is a problem

3) What is VDD connected connected to PGD

4) Also what do you mean by upper and lower threshold for UVLO and OVLO

5) I do not know my output load capacitance to accurately enter in operating condition sections, so what would be a good value ?

Thanks

Looping in Avishek for design review of LM5069

Closing the thread here as a separate e2e thread has been created for  LM5069 design review.

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1119703/lm5069-design-review