LM36274: LM36274_Frequency of the internal Charger pump be adjusted?

Hi Will,

The frequency of LCM boost and charge pump are fixed. May I know what is the purpose that you want to adjust the frequency?

And may I know what is the frequency range you want? Then I can recommend the suitable solutions.

BR

Patrick

Hi Patrick,

Sorry for the late reply,

I have a display product that uses this IC for power supply. The frequency of its touch function conflicts with the switching frequency of this IC, which is why I am inquiring if it can be adjusted.

If you have any other recommended IC models, I would appreciate it if you could provide them for my reference.

Thank you.

BR, Will

Hi Will,

So could you please give me a frequency range that could meet your requirement?

BR

Patrick

Hi Patrick,

The switching frequency range used in our product is 120KHz ± 30KHz.

Thank you.

BR, Will

Hi Will,

Currently we don't have solutions could support such low frequency. But based on my understanding, the touch screen will usually support several hundred kHz frequency as well?

BR

Patrick

Hi Patrick,

Sorry, I may not have expressed myself clearly, leading to a misunderstanding. Here is the clarification:

1. Could you please confirm the default frequency of the Inverting Charge Pump (VNEG) provided for negative voltage (VNEG) by LM36274?
2. My product operates within the frequency range of 120KHz ± 30KHz. I would like to avoid the default frequency of the negative voltage provided by LM36274, even if it is higher than my product's frequency (e.g., 200KHz, 300KHz, 400KHz, etc.)."

Hi Will,

Understood, I will check the charge pump frequency and give you feedback later.

BR

Patrick

Hi Will,

May I know what is the load current on VNEG? LM36274 has a PFM mode on the charge pump, so the frequency will also be impacted by load.

BR

Patrick