nRF52832 Deep Sleep mode Power Consumption with Ram Retention Off

RE: nRF52832 Deep Sleep mode Power Consumption with Ram Retention Off

Justin — Fri, 29 Jul 2022 15:47:33 GMT

[quote userid="65515" url="~/f/nordic-q-a/90267/nrf52832-deep-sleep-mode-power-consumption-with-ram-retention-off/379176"]Holiday time in Norway [/quote]

Sorry I wasn't aware of that.

[quote userid="65515" url="~/f/nordic-q-a/90267/nrf52832-deep-sleep-mode-power-consumption-with-ram-retention-off/379176"]Use the PPK2 to see this in operation.[/quote]

Will try this out. Thanks for the update @hmolesworth

RE: nRF52832 Deep Sleep mode Power Consumption with Ram Retention Off

hmolesworth — Thu, 28 Jul 2022 16:31:52 GMT

Holiday time in Norway .. in case this helps, there is no RAM refresh as the nRF52832 internal RAM is fully static (SRAM) and not dynamic (PSRAM, DRAM, ...) however the internal DC-DC converter which generates 1.3 volts from VDD changes from DC-DC or LDO Mode into Hysteretic Mode in deep sleep which is like skipping a stone across a pond; periodically the external bulk capacitance is charged up (so current pulse) and then the internal supply switched off until the internal voltage decays a little then the process is repeated. Use the PPK2 to see this in operation.

RE: nRF52832 Deep Sleep mode Power Consumption with Ram Retention Off

Justin — Thu, 28 Jul 2022 12:36:11 GMT

Simonr Can you please look into this?

RE: nRF52832 Deep Sleep mode Power Consumption with Ram Retention Off

Justin — Mon, 25 Jul 2022 04:43:24 GMT

What is the RAM refresh rate? We see that in deep sleep mode for every 300ms there is 0.4µA current draw. We work on an implantable device and 0.4µA is a cause of concern when it comes to longevity of the device.

Can you please help me in reducing this additional current draw?

RE: nRF52832 Deep Sleep mode Power Consumption with Ram Retention Off

Simonr — Fri, 22 Jul 2022 11:36:57 GMT

0.4µA is within the variance one could expect as the current consumption varies a tiny bit between devices, and we also have to take into count leakage and current draw from other components on your board. I would say 0.4µA is not abnormally high and you seem to have entered system OFF correctly.

Best regards,

Simon