TPS92314: ILED accuary

KANJI SHIBATANI

Mastermind 6205 points

Part Number: TPS92314

Hello

My customer chosen TPS92314 for their new project on 2019 with following spec.

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Non-isolated

Input AC220V

LED voltage :60V

LED current:350mA +/- 5%

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What factor affects to final product's accuracy * as TPS92314 IC's spec? ( excluding external conditions i.e. components tolerance / input voltage tolerance..)

I think Vref affects to accuracy , but anything else?

( * Customer's goal is +/- 5%,... it should be very tough)

ILED depends on VREF accuary : TYP 0.14V, does not specifined in electrical characteristics in d/s.

Can we assume Vref accuary is 0.14V +/- 6% ? ( Why 6% ==> Visns specified as 1.15V(TYP)/1.22V(MAX) in the data sheet )

We have to trim Risns if ILED accuary is necessary?

Please give your opinion about trimming.

Thank you for your support!!

Best Regards

over 6 years ago

0 Irwin Nederbragt over 6 years ago

TI__Mastermind 28655 points

Hello Kanji,

Q1: Please check the 230V EVM, www.ti.com/.../TPS92314A19230VEVM
It shows the min/typical/max LED current for the design, 330/350/370 which is 94.3%, 100%, 105.7%. The current sense resistor is a 1% that can be changed to a 0.1% as well.

Q2: I am asking about this.

Q3: That is possible but if the EVM states the regulation percent slightly high it may not be necessary with higher tolerance components.

Regards,

0 KANJI SHIBATANI over 6 years ago in reply to Irwin Nederbragt

Mastermind 6205 points

Dear Irwin-san

Thank you for your quick support every time!!

I am waiting your advice about accuracy of Vref.

My uderstanding is TPS92314EVM LED current accuracy 94.3/100/105.7% does NOT include

Vref accuracy.

So, if Vref was +/-4%, then total accuracy(MAX) is +/- 10%.

If my understanding was wrong, please let me know.

Thank you for you support

Best Regards

0 Irwin Nederbragt over 6 years ago in reply to KANJI SHIBATANI

TI__Mastermind 28655 points

Hello Kanji,

This is the information I received:
"From my limited knowledge, the 0.14 V is resistor divided version of the reference voltage with 1.21 V as min, 1.24 V as typ and 1.3 V as max.
In theory, it’s possible to have +/-5% LED current tolerance achieved."

Best Regards,

0 KANJI SHIBATANI over 6 years ago in reply to Irwin Nederbragt

Mastermind 6205 points

Dear Irwin-san

Thank you for your answer !!

I appreciate for your support

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TPS92314: ILED accuary