10 posts / 0 new
Last post
wsiaxel
Offline
Last seen: 8 months 4 days ago
Joined: 2014-01-13 10:33
Buck mode DCDC output voltage

What is the output voltage of the internal DCDC (at the VDCDC pin) when running in Buck mode??

BB_Dialog
Offline
Last seen: 2 months 1 week ago
Staff
Joined: 2013-12-05 14:44
The output voltage at the

The output voltage at the Vdcdc pin is about 1.4V

Best regards, Dialog Support.

wsiaxel
Offline
Last seen: 8 months 4 days ago
Joined: 2014-01-13 10:33
DCDC frequency

What is the working frequency of the internal DC/DC circuit ?

BB_Dialog
Offline
Last seen: 2 months 1 week ago
Staff
Joined: 2013-12-05 14:44
DCDC switching frequency

Hi,

the switching frequency of the DC-DC converter is about 1MHz.

B.R., Dialog Support

behzad
Offline
Last seen: 3 years 2 weeks ago
Joined: 2015-01-27 17:53
Vdcdc is 1.1v

Vdcdc is 1.1v
In my custom designed board with DA14580-01 QFN40 in buck mode, the output voltage of Vdcdc is 1.1 instead of 1.4v. And the SoC is not found by SmartSnippets and returns "Failed downloading firmware file to the board." The board is powered by the basic evaluation board and JTAG (TMS/TCK) is connected for programming the board.
Vbat_RF and Vbat-3v are both 3.29v.
Is Vdcdc being 1.1v the problem and any idea what had caused this?

JE_Dialog
Offline
Last seen: 8 hours 2 min ago
Staff
Joined: 2013-12-05 14:02
Hello behzad, what is the

Hello behzad, what is the input voltage and source to your board ? and is the 1.1V steady, low noise and low ripple , or is it noisy with high pk-ok ? (i.e. do you measure on a DMM or look at it on a scope).

BR JE_Dialog

behzad
Offline
Last seen: 3 years 2 weeks ago
Joined: 2015-01-27 17:53
the input voltage is 3.3v and

the input voltage is 3.3v and the board is powered by the Basic Development kit.
the 1.1v is quite steady with low noise and low ripple. measured by scope.

JE_Dialog
Offline
Last seen: 8 hours 2 min ago
Staff
Joined: 2013-12-05 14:02
Hello Behzad, the dc-dc

Hello Behzad, the dc-dc should be 1.41V typical : all other circuits (digital and core) run from LDO connected to this suplpy, so if its 1.1V, then this will be a problem. Only a part of the analog /RF runs from the 3V .. (as configured in buck mode). 

What do you see on the SWITCH pin - is there a good clean waveform switching wavefor (GND to VCC) that is input ot the L/C filter of the dc-dc ?

What are the values you use for the inductor and capacitors on the dc-dc ?

First it is crtical just to get the device to start up : i would remove all other connections first and focus on that in isolation. when the device boots. You can compare what you see on your custom board vs what you see on the BASIC board.

BR JE_Dialog

 

BR JE_Dialog

behzad
Offline
Last seen: 3 years 2 weeks ago
Joined: 2015-01-27 17:53
Inductor is 2.2uH and

Inductor is 2.2uH and capacitors 1uF (0603) and and using 8mm meander line as shown in your guidelines.
I populated another board with only the device and its essential components. Using QFN40 still vdcdc remains at 1.1v. It's smooth, clean and not noisy.
Then I made a new board using QFN48 chip with the same schematics and this time the vdcdc voltage is correct at 1.42v.
However JLink/JTrace in uVision or Smart Snippets still does not find the SW Device (Cortex M0). I have probed TMS and TCK close to the SoC and they look fine in scope working at 200KHz.
The VCC voltage is also clean at 3.26 v powered by the basic development board. The same DA14580-01 device on the development board can be found by either smartsnippets or uVision with no problem.
Any idea why the DA14580-01 is not responding to JTAG?

clementb
Offline
Last seen: 5 years 4 months ago
Joined: 2015-04-22 10:16
Hi,

Hi,
I have the same problem, do you find a solution?
Clément