CC2640 DCDC_SW pin 33 output

Hi all,

I am working with a customized PCB with CC2640 7X7 on it.  TI 'Simple Observer' programme is running in CC2640.

And the following output is observed on Pin33 DCDC_SW,

Can someone help me to understand what this waveform indicates. Many thanks in advance.

Cheers,

Sujata

Can you post your schematic? What is the purpose of probing that pin? If you want to see if the DCDC_SW is operating, then you should program CC2650 with standby only image and probe on the 10uH inductor(close to the VDDR, not the DCDC_SW end)

Hi Christin,

The purpose is to check how all pins are behaving when CC2640 is in Observer mode. And I want to use CC2640 and not CC2650. When I connected a probe to pin 33 (DCDC_SW) the above waveform is observed. And I could not understand what this waveform indicates?

As per TRM DCDC_SW is connected to VDDR though 10µH inductor and 10µF Capacitor.

Cheers,
Sujata

Hi Sujate,

DCDC-SW is the switching output of the internal DCDC regulator. It switches current through the 10 uH inductor to create a stable voltage over the 10 uF capacitor.

Cheers,

Fredrik

Hi Fredrik,

Thank you very much for the explaination.

But about the waveform is the normal to have this kind of waveform at DCDC_SW pin?

Cheers,

Sujata