I have a design based on a CY8C3865LTI-014.
I noticed that in reality the sleep current was much too high than anticipated (more than 25µA higher).
The steps I took to debug this were:
- remove all components but the PSOC and the surrounding caps from the PCB
- build a fresh project without components, and only this code:
CyGlobalIntEnable; /* Enable global interrupts. */
// set 32kHz crystal to operate in low power mode when in sleep
/* Place your initialization/startup code here (e.g. MyInst_Start()) */
/* Place your application code here. */
// clear wdt
// sleep 1 s
As one can see, after initialisation, the PSOC goes in sleep mode forever.
When measuring the current, I still measure ~28µA, which is much more than the specified 1µA in the datasheet.
What could be the cause of this high sleep current?
I attached the project for you reference.
Thank you for your reaction!
In attachment you will find:
- the schematic and board layout
- a picture showing the board I used for current measurements, where I desoldered all components except the PSoC and the caps and xtal surrounding it.
Thank you in advance for all your suggestions and remarks!
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Please check whether the PSoC itself is consuming 28uA or the current consumed from the entire circuitry is 28A. Please note that there will be leakage currents based on the components and board design. Please confirm this.
Regarding PSoC firmware side, enabling the external oscillators will draw more current. So please be aware of this.
Follow the kit schematics for CY8CKIT-001 and PSoC 3 module and design accordingly.