TPS65910: UL evaluated PMIC under QVGS,  file E169910 (Protectors, Low-voltage Solid-state Overcurrent - Component)

Hello Hemal,

UL certification is not part of the IC development or qualification process, so we typically don't have UL certification for our devices. This is generally done at the system/module level.

Regards,
Karl

Thanks Karl for the response. I see there are some TI PMIC which were UL evaluated at the chip/device level. Below link shows the devices which are UL evaluated:
database.ul.com/.../showpage.html

Do you know how were the above devices UL evaluated?

While talking with UL the representative mentioned that the TI PMIC can be UL evaluated but it will still need followup inspection at IC's manufacturing location. Not sure how does that work, boards will be tested at system level at our site, but also there seems there will be followup inspection at TI site, do you how TI handles it?
Thanks

Hi Hemal,

It looks like the two closest devices to PMICs which were evaluated were TPS6528x and TPS6598x, buck + power switches. You are right that these can be done at the component level, but it is not commonly done, only in specific cases. As mentioned before, this is not a common process for TI devices, and is not supported for TPS65910.

But this should not stop you from being able to use the part in a UL-tested system, since these can still be evaluated at the system level.

Regards,
Karl

Karl:

We are planning to do the testing of our system with TPS65910 on the board. But according to UL "We still need a follow up inspection at the IC’s manufacturing location." How does TI handle follow up inspections at the site of chip manufacturing? There will be UL inspections done at your manufacturing site, can this product be added to the Follow up inspection list?

Just looking at options, how to handle to UL evaluation of the TP65910 chip.

Thanks.

Hi Hemal,

TI cannot support UL Follow-Up Services inspections of the manufacturing site for this product since it is not a TI UL Recognized Component.

Instead, your end product UL Listing may require supplemental protective components for the battery/battery back-up (as an example) to satisfy your end product’s UL Listing. Requirements for supplemental components will be based on your specific, end product UL Standard of Safety along with any applicable component level UL Conditions of Acceptability interfacing with the TPS65910.

Regards,
Karl

Karl:

The RTC backup battery we are using is rechargeable and UL approved. TPS65910 has Backup battery charging current maximum of 700uA. Looks like the QVGS2 file is looking for max Voltage range ( which is less than 20VDC)/ Maximum continuous current/ Protective current values this IC can handle

http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/showpage.html?&name=QVGS2.GuideInfo&ccnshorttitle=Protectors,+Low-voltage+Solid-state+Overcurrent+-+Component&objid=1074427573&cfgid=1073741824&version=versionless&parent_id=1074427572&sequence=1

Do you have any test results to show TPS65910 can provide the protection needed by UL file?

Thanks,

hemal

Karl:

We are using MS920SE lithium rechargeable battery and below is what I got from UL

These cells have been subjected to an abnormal charge test which subjects the cells to a constant current (CC) charge method followed by a constant voltage (CV) charge method. The test limit parameters for the abnormal charge test are outlined in the table below. The charging circuit in the end use application shall limit the charging current and charging voltage to the levels noted in the table under both normal and single fault condition. If the charging current and voltage in the end use application cannot be maintained at or below the levels noted in the table or if the charging method is different from the CC/CV method noted above, additional evaluation and testing may be necessary.

 

MS920SE

Maximum Charging Current (Ic), mA  300

Maximum Charging Voltage (Vc), V dc 3.4

 

Do you know if TPS65910 supports the above requirement?  If not,  additional evaluation needed.

 

Thanks,

hemal

Karl:

Thank you for your response!

We have this PMIC TPS65910 used in three of our boards which got transferred from Australia. Now the boards are going through UL testing, and seems too late to change the design, unless there is pin replacable PMIC. We have two options:

1. Use PMIC TPS65910: A new UL file needs to be created so TPS65910 is UL evaluated. We purchase more than 1000 units/year at production level with these three boards. Since TI has other PMICs ( not pin replacable)  under same category and has experience with the UL evaluation it will be beneficial to use it. Does TI see this PMIC going End of life or any other reason why TI cannot support UL evaluation of this PMIC?

Change of PMIC will need lot of changes on our side like safety retesting, CE retesting, etc in additon to spin on all three boards.

2. Alternate PMIC: We will need alternate UL evaluated PMIC which meets this max charging voltage and current requirement for the rechargable battery. Can you suggest alternate PMIC which can meet the requirement on max charging current and voltage for the battery mentioned earlier?

Do you know of any other alternatives?

Thanks,

Hemal

Karl:
Can you explain more on "your end product UL Listing may require supplemental protective components for the battery/battery back-up (as an example) to satisfy your end product’s UL Listing." ? We are using the PMIC to provide max charging voltage and current for the battery ( which is within the limits of the PMIC). Do you have an example of protective components which can be used?

Thanks,
hemal

Hello Hemal,

It really depends on the system. For example, if you needed to limit the voltage of a certain node, you could consider a clamping diode. Or to limit the current of a specific line, you could put a resistor in series. So depending on your system goal, you may need to add components to achieve this.

I can't provide any specific recommendations, since we haven't developed a UL certified board.

The TPS65910 PMIC has 700uA max charging current, and selectable 3.15V, 3V, 2.52V, or VBAT end-of-charge voltage. So I think this already meets the requirements you provided before. You could consider other similar PMICs like TPS65911 or TPS65912 (assuming they meet your power needs), but you will still need to make sure the system meets the UL requirements at the board level, regardless of which PMIC you choose.

Regards,
Karl