DCDC_SENSE on RT1050

[variable_andrew]

The DCDC_SENSE signal is listed in the RT1050 datasheet as a pin... with no comments or text about what it's needed for. 

In the RT1050RM, DCDC_SENSE's only mention is showing is directly connected to VDD_SOC externally to the chip. 

Is it required to short DCDC_SENSE to VDD_SOC on my board? Do I need to do anything else with this signal?

The reason I ask is we're not seeing the main 24MHz Crystal starting up on this new board w/ the RT1050, wondering if this could be a cause for that (or what else the DCDC_SENSE is needed for)?

[fangfang · Accepted solution]

Hello,

DCDC_SENSE is for checking the output voltage. Please connect DCDC_SENSE to VDD_SOC.You may refer to the EVK board.

Best regards

[variable_andrew]

Hello fangfang‌, 

Can you confirm that not having this connection would cause XTAL0 to not give a clock?

Or is DCDC_SENSE just required for other logic, and we need to do further debug before spinning a new board if our problem now is XTAL0?

We have made a few different RT board designs now, our RT1015/RT1020 boards all work fine (XTAL0 clock looks good @ 24MHz), so we copied that clock circuit over to our RT1050 board (resistor/capacitor pairs), but on the RT1050 XTAL0 doesn't have any pulse, it's just a flat signal. 

For some reason our RT1050 design has a clock signal from XTAL1 though, so it's just XTAL0 that's dead.

Thanks!

[fangfang]

Hello,

 In order to better service for you, would you please provide the schematic for the oscillator?

[variable_andrew]

we managed to do open heart surgery on the PCB and connect DCDC_SENSE -> now getting 24MHz on XTAL1, so that was it. thanks