LM20143 - condition and implication working with switching frequency of 32kHz

Marcin Paszkiewicz

Other Parts Discussed in Thread: LM20143

Customer is mine is creating application of industrial tester.

To power supply camera subsystem they need to build circuit allowing to convert from 3.3V to 1,2V with 2A, Obstacle here is that this should be achieved 32kHz switching frequency which they want to achieve by selecting tight resistor RI.

As LM20143 has min frequency is 500kHz question is if they can reach required 32kHz and how this will implicate parameters, reliability and work life time of product.

Are you able to help to answer that question?

over 9 years ago

0 Haifeng Fan over 9 years ago

TI__Intellectual 1135 points

We usually don't recommend to operate the device under an out of sepcification condition. 32kHz is way lower than the min switching frequency 500kHz, and the device has not been characterized in that condition.

0 Jakub Juchner over 9 years ago in reply to Haifeng Fan

Prodigy 10 points

Hello,

I understand that you don't recommend to operate out of spec but the question is if did you make any test what will happen if we use different frequency? or based on what kind of rules current range has been defined? is it connected to shorter liftime or?

I see also that in previouse message there is mistake. we would like to operate device in 32MHz instead of kHz., so much higher than limits

0 Haifeng Fan over 9 years ago in reply to Jakub Juchner

TI__Intellectual 1135 points

Hi,

The LM20143 is not able to operate with 32MHz switching frequency.

Thanks.

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LM20143 - condition and implication working with switching frequency of 32kHz