LPC824 power down current too high

[lpcware]

Content originally posted in LPCWare by pgr on Mon Oct 12 09:19:18 MST 2015
Dear all,

I am working with an LPC824 that sleep in power down mode. According to the datasheet the current should be 1.6uA typical 10uA maximum.
I have disabled BOD and watchdog oscillator, most IO are in output and set to 0 and few are in inputs with external high value pull-up resistor but all IO are in a valid, not floating, state.

I measure a consumption of around 30uA. Any idea how I can improve this ?

Any idea is welcome as I am going crasy !

PGR

[lpcware]

Content originally posted in LPCWare by pgr on Tue Jan 05 09:22:38 MST 2016
Yes I was able to go close to 1uA as specified in the datasheet using the two following tricks:

- The TSSOP20 chip is in fact the same than the QFN33 one with few IO not connected, so all the IOs not used on the TSSOP20 but present in the QFN33 version should be set as GPIO output low level even if you don't see it on the TSSOP20 datasheet.
- If you connect anyspecial function to any IO using the SWM, the corresponding GPIO should be also set output low. For example if you connect UART TX to pin 0.5. The GPIO 0.5 should be set as output low.

Let me know if it help

[lpcware]

Content originally posted in LPCWare by cgroen on Tue Jan 05 08:24:52 MST 2016
I'll answer my own question,
The I2C open drain pins had to be set to outputs, low level and disable pull up/down, was left out in my code :(
Current is now down to 2 to 4 uAmp :)

[lpcware]

Content originally posted in LPCWare by cgroen on Tue Jan 05 07:39:48 MST 2016
PGR,
did you manage to get a solution to this ?
I have a LPC824 mounted in my own board (20 pin TSSOP) and I see also 30 to 31 uAmp in powerdown mode. The current I measure is what goes into the CPU, nothing conneced to it besides power!
I set all I/O to output (set to 0) and all pullup/down are inactive in the chip.

Any advice ?

[lpcware]

Content originally posted in LPCWare by rocketdawg on Mon Oct 12 12:40:40 MST 2015
Most likely your external inputs and outputs.  They will draw power.  You can prove this by testing a unmounted LPC824 and seeing what power it draws with no inputs/outputs.