LM5574-Q1: Max switching frequency

Rohit J

Intellectual 850 points

Part Number: LM5574-Q1
Other Parts Discussed in Thread: LM5574, LM25574

Hello,

Can you confirm the max switching of LM5574?

Page one says that it can work between 50kHz - 500kHz but Fig 1 on page 7 shows 800kHz is possible.

Thanks,

Rohit Joshi

over 6 years ago

0 Katelyn Wiggenhorn over 6 years ago

TI__Genius 11040 points

Hi Rohit,

This device's recommended switching frequency range is 50kHz - 500kHz. The LM25574 can operate from 50kHz - 1MHz.

Best Regards,
Katelyn Wiggenhorn

0 Rohit J over 6 years ago in reply to Katelyn Wiggenhorn

TI__Intellectual 850 points

Hi Katelyn,

I cannot use LM25574 since I need 70Vmax rating. Can you help me understand why the max freq spec is 500kHz while the graph shows that 800kHz is possible?

Thanks,
Rohit

0 Katelyn Wiggenhorn over 6 years ago in reply to Rohit J

TI__Genius 11040 points

Hi Rohit,

I understand that the LM25574 will not work for your application.

The LM5574 datasheet states 50kHz to 500kHz as the range, and this range will have been tested across corners during development. Figure 1 would have been taken based on a simulation run or one set of bench measurements. This is not guaranteed operation.

Webench also supports the 50kHz to 500kHz range.

Best Regards,
Katelyn Wiggenhorn

Power management

Power management forum

LM5574-Q1: Max switching frequency