TPS92620-Q1: duty cycle by 0.01%

Zena Lee

Part Number: TPS92620-Q1
Other Parts Discussed in Thread: TPS92520-Q1

Hi team,

Customer asked for LED driver recommendation. Requirement as below. Application is WPC in automotive.

- 2 channel, each max 200mA

- 200Hz freq, with 0.01% unit duty cycle control

To operate with 0.01% duty cycle for 200Hz means IC need to control within 50ns.

I noticed that TPS92520-Q1 have rise/ fall time of few us timing so unable to handle 200Hz with 0.01%.

Could you check if my understanding is correct, and suggest other LED driver within this spec?

Thank you.

0 Hailee Xu 7 months ago

Hi Zena,

Yes, your understanding is correct.

There is min-on/off time requirement for PWM mode performance.

BR,

Hailee.

0 Zena Lee 7 months ago in reply to Hailee Xu

Thanks, then could you recommend other IC that fits the requirement then?

0 Hailee Xu 7 months ago in reply to Zena Lee

Hi Zena,

Please kindly help me check some detailed requirements about this application - PWC in automotive.

What is the actual load on this application? and why is such small duty cycle required? will it change?

and what does the 0.01% control current look like, reach the nominal value?

BR,

Hailee.

0 Zena Lee 7 months ago in reply to Hailee Xu

Hi Hailee,

It is for WPC item in automotive application, which charges phones.

LED driver is used for indicator. OEM is Hyundai (HKMC).

I'm not sure why it has to be controlled within 0.01% duty cycle, but it's the requirement.

0 Hailee Xu 7 months ago in reply to Zena Lee

Hi Zena,

I tested the EVM board, from the test result, this device can support 0.05% PWM duty cycle at 200Hz with 20nF Cout.

As the duty cycle gets smaller, the shape of the output current changes.

Could the customer consider Switching LED drivers or with the digital interface?

BR,

Hailee.

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