Detailed current consumption during connected mode

[Marly]

Hi, where could i find detailed current consumption and timings (wake-up, rx, tx, power down) in connected mode for RF51822, in order to compute average current value for various connection interval ? Would you have at least current consumption value for 1s interval@3V@0dB ? Thanks. Stan

[Ole Morten]

You can find detailed current consumption curves in the S110 SoftDevice Specification. To get numbers for the symbols used, you should refer to the nRF51822 Product Specification.

While in a connection with 1 s interval and 0 dB TX power, transmitting 10 bytes of data per interval, you should see about 20 µA average current consumption.

[Marly]

OK, thanks. Is there a table for the precise timing values, or should I extrapolate it from the figure 9 ? Stan

[Ole Morten]

That is the best suggestion for now, yes. The time in RX and TX will also be dependent on how much data is being transferred. If you have a specific scenario in mind, I'd be happy to run some numbers through our internal tools. I can unfortunately not share the tools themselves, since they include confidential information. To do this, the following details are needed:

• 32 kHz clock source precision on both Central and Peripheral
• connection interval and slave latency, or
• advertising interval
• data payload

[Marly]

I just want the connected value, 1s interval, latency 0, no data. Based on the figure 9 and on the data that I have found on priduct spec, I get (it took me one hour to solve the hunt). an average value of 7,7mA for 2.2ms, and 3,1uA for 997,8ms => Average value of 20uA. Stan

[Ole Morten]

This is in line with what I get with our internal tool for such use case (which I also gave in my initial reply), assuming 250 ppm external crystals. If you have good 32 kHz crystal (20 ppm) on both ends, you could get down towards 16 µA. Also, beware that if you use the internal RC, you'll have to add some µA on top of the 250 ppm value, probably ending up at 24-25 µA.