CCS/CC1310: CC1310 consumption

- Do you know that the current is drawn by the CC1310?

- How do you know the distribution between RF and MCU power? 

I would like to get the fundamentals before I start looking deeper into this. 

We are running further tests

We still want to monitor the case and not ask for it If we turn off the RF part, the consumption is 5mA when we reactivate it is 20mA we are trying to understand why

Eventually I can send and schematic and firmware for further information

Best regards

Is the power consumption measured with something you know is a 50 ohm load? 

Do you get the same if you use the rfPacketRX example unmodified from the SDK? 

Yes the antenna is 50ohm

we tested with both SDK and RF studio
Our controller is CC1310F128RHB
We have tested with the launchpad demoboard with CC1310F128RGZ the consumption is correct

If I understand you correctly, you get the expected current consumption if you test on a launchxl-cc1310 but not if you test on your own board? 

If that is the case I would recommend requesting a schematic and layout review through https://www.ti.com/tool/SIMPLELINK-SUB1GHZ-DESIGN-REVIEWS

4812.Schematic.pdf

Not related to the topic but why is C19 set to 12 pF? I would have expected a larger value for a DC block on this frequency. 

Is this measured with the debugger connected? Have you tested with the rfPacketRX example without the debugger connected? 

Not related to the topic but why is C19 set to 12 pF? I would have expected a larger value for a DC block on this frequency.

We also tested a 100pF capacitor but the result is the same

Is this measured with the debugger connected? Have you tested with the rfPacketRX example without the debugger connected?

YES

I intend to do a measurement but I have some other measurements I have to do first. 

If I flash a CC1310 with the rfPacketRx example, CC1310 draws 6.1 mA

Hello,

Using our application with CC1310F128RHB connected to the lanchpad demoboard (used as programming / debugging) the consumption is 20mA.

If I measure the current of the demoboard that uses CC1310F128RGZ the consumption is 7mA.

To do the tests we used SmartRF Studio 7.

Why ?

If you flash your custom board with the rfPacketRX example and disconnect the debugger (just power the board from a supply), do you then measure 20 mA?

Yes, even if I flash with our custom card with the example rfPacketRX and the disconnected debugger and with an external power supply measuring 20mA.

If you don't have any TX on, the rfPacketRX example will always be in RX and the MCU will always be off. 

I don't see anything on the schematic that would indicate increased current consumption.

- Does the DCDC operate? Do you see a difference in the current consumption with the DCDC activated and deactivated? 

YES, DCDC operate correctly.

Switch OFF DCDC current consumption decrease but, it is always 2-3mA higher than the demoboard.

Switch ON DCDC current consumption increases 13mA than the demoboard.

Meaning that your board draw 9 mA with DCDC on and not 20 mA as you wrote? (6 mA + 3 dB "more")

Are you using the same parts as the reference design (I I see that they have the same value, but part number etc)

Our board with the DCDC on in RX mode current consumption is 20mA (13mA than the demoboard)

Our board with the DCDC off current consumption is 5mA (2-3 mA than the demoboard)

Our board uses the same value the reference design no the same part number

Sorry, is the DCDC on power consumption 15 mA higher than the DCDC off power consumption?

YES

with DCDC on power, current consumption increase by 15mA

Would you be able to use the same part numbers for L3 and C12 as the Launchpad on one board? The current should not increase if you turn on the DCDC. Either it's a layout issue or related to the exact part you are using. Could you share the part numbers for L3 and C12 which you use on your board?

L3  MURATA LQW18AN6N8C00D

C12 TDK C1608X5R1A226M080AC

I would guess that the inductor causes the high current draw. We are currently in the process of testing a few different inductors to increase the number of validated parts but the one you are using is not one of them.

Start by testing with the same part as we have in our ref design to verify that the selected part causes what you are seeing.