Finding F(sw) of L5991 SMPS?

[cupoftea]

Hi, Page 9 of the L5991 (SMPS controller) datasheet gives the switching frequency as in (1) on page 9

https://www.st.com/resource/en/datasheet/l5991.pdf

We have RA//RB = 68.1K and CT = 220p.
According to equation (1) on page 9 of the datasheet, this means a frequency of 11.1 milliHertz which cant be right.
Do you know the proper equation for fsw?

 

[KlausST]

Hi,

F_osc = 1 / (CT ⋅ (0.693 ⋅ (RA // RB) + KT) = about 96 kHz

Klaus

 

[FvM]

You may want to ask for a corrected datasheet, original equation (1) is missing the closing paranthesis. KlausST apparently supplemented it by applying common knowledge.

 

[Easy peasy]

equation 2 on same page clarifies the situation for the patient and/or careful reader