4 posts / 0 new
Last post
Gibo
Offline
Last seen:5 years 1 week ago
加入:2016-04-13 03:53
Power consumption and lifetime

Dear Dialog,

We have some quetion.We use DA14580.Question is below.

(1)DA14580 started by Peripheral mode.
Power consumption was about 14uA mesured by multimeter, when advertise interval is 500ms(include Extended Sleep).
We calculated using the value of Power consumption of Peripheral mode that is listed in Table.15 of UM-B-019, but Power consumption was not to 14uA(12.15uC ÷ 500ms ≒ 24uA).
Which is correct of measured and calculated?

(2)"when the DA14580 is idle, the current consumption is about 0.6 mA." is listed #4 of Previous Post.
(http://support.dialog-semiconductor.com/power-consumption-da14580)
This "idle" is will be of Connection event of Table.15 of UM-B-019?

(3)How did calculated lifetime of CR2032 that "Beacon mode only" of Table.16 of UM-B-019?
Please tell me the calculation method of lifetime and lifetime at the advertise interval 500ms,50ms,and 20ms.

(4)Why not become lifetime five times even if the advertise interval became five times?
[example. Sending interval:100ms → 500ms(x5), lifetime:3.7months → 16.4months(x4.4)]
Reference:UM-B-019 Table.16 Beacon mode only.

Best Regars,
Gibo

Device:
MT_dialog
Offline
Last seen:2 months 3 weeks ago
Staff
加入:2015-06-08 11:34
Hi Gibo,

Hi Gibo,

1) The power consumption indicated by the application note is measuring the average current consumption in an active period 9.85ms (where the 580 is active). In order to measure the average power consumption of your device you can follow this FAQhttp://support.dialog-semiconductor.com/faq-page#n366.

2) This idle state is when the 580 is awake not transmitting or receiving, just awake.

3) For the calculations the data from the application note are used, we found the overall consumed charge of the beacon (using smart snippets), that means that we ve calculated the charge consumed for the period the 580 stays inactive (sleep) and added the charge cosnumed when active 9.6uC in order to find the total power consumption in an interval, then we find the power consumption in a second and so on, after that we calculate the available charge of the battery and apply the divison. Now about the lifetime depends on the mAh of the battery you can check from the table of the beacon application note regarding the 20 and the 10 ms advertising interval for a 240mAh, this can last approximatelly up to 1 month and 0.7 months, and for a 70mAh this should last approximatelly 0.3 months and 0.2 months respectively.

4) The calculation is a rough approximation of the expected life of the beacon device, since the advertising interval isn't steady, in real life the results will vary.

Thanks MT_dialog

Gibo
Offline
Last seen:5 years 1 week ago
加入:2016-04-13 03:53
Dear MT_dialog,

Dear MT_dialog,
Thank you for reply.

We adding question below.

Respect to (1),
We measured Power consumption using SmartSnippet-PowerProfiler.
As a result, it was about 12uA.(Advertise interval is 500ms)
As some posit, Power consumption of extended sleep was 0,
Power Consumption of Beacon is 9.53C ÷ 500ms ≒ 19uA.
Measured value and calculated value is different.
This calculus equation is wrong?

Respect to (3),
We calculated result of lifetime is below.(used CR2032)
50ms:1.7month,20ms:0.7month.
Different to your reslut.
Will you presented "equation"?
Also, Is it correct that the advertising interval is 10ms?

Best Regards,

MT_dialog
Offline
Last seen:2 months 3 weeks ago
Staff
加入:2015-06-08 11:34
Hi Gibo,

Hi Gibo,

1. The 9.53 is not the charge for all the 500ms interval, but for the 9,85ms the device is active and doesn't sleep, you can calculate the amount of charge that the 580 consumes. So since the power consumption for extended sleep is 1.34 uA then the charge for 500ms interval is (500ms - 9,56ms) * 1,34 + 9,53uC = 10,18uC therefore about 10,18uC / 500ms = 20,36 uA. Please check the smart snippets attached capture for the confirmation of the value.

2. The equation is the one i mentioned above, and sorry i though that you wanted a measurement for 10ms and 20ms so i pluged it in, please ignore the above values the ones below are the correct ones. Also please note that this is an approximation.

for 500ms approximately 4,7 months for 70mAh &16 months for 240 mAh

for 50ms approximately 0,5 months for 70mAh & 1,7 months for 240 mAh

for 20 approximately 0,2 months for 70mAh & 0,7 months for 240 mAh

Thanks MT_dialog

Attachment:
Topic locked