AT86RF211DB-868LT Atmel, AT86RF211DB-868LT Datasheet - Page 17

• Manufacturer Part Number: AT86RF211DB-868LT
• Description: BOARD DAUGHTER AT86RF211/868MHZ
• Manufacturer: Atmel

Specifications of AT86RF211DB-868LT

• Module/board Type: Daughter Board
• For Use With/related Products: AT86RF211 @ 866MHz
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: AT86RF211-DB868107; AT86RF211DB868107; AT86RF211DB868107; AT86RF211DB868LT

Calculation of Power
consumption
Hypothesis & Method
Application: Transceiver vs.
Single Transmitter
2186A–WIRE–08/02
WUR = '00 1000 1001 1110 0010' for data rate = 8 kbits/s (corresponds to 80 x 1.56 µs)
WUR = '00 1000 1000 1100 0010' for data rate = 9 kbits/s (corresponds to 71 x 1.56 µs)
WUR = '00 1000 0111 1110 0010' for data rate = 10 kbits/s (corresponds to 64 x
1.56 µs)
WUR = '00 1000 0111 0010 0010' for data rate = 11 kbits/s (corresponds to 58 x
1.56 µs)
WUR = '00 1000 0110 1000 0010' for data rate = 12 kbits/s (corresponds to 53 x
1.56 µs)
RATETOL = 2 x 1.56 µs.
- WUC register: WUE = '1', DATA = '0', STOP = '0', DATAL = '00000', ADD = '0',
MSGTST = '0', WPER = '001100011', WL1 = '0000001' for all data rates, WL2 '010',
ISTU '1' so:
WUC = '1000 0000 0000 1100 0110 0000 0101 0100'.
- WUA is unused as no Address field is expected.
The capacity of a battery is given in A.h that corresponds to an electric charge (Q = I . t).
It is measured with given discharges conditions (discharge current up to a final voltage).
Atmel assumes that in practical half of this value can be really used because of current
constraints of the application (operating voltage > 2.4V, self discharge, T°...). Let's call
Qb = Q/2.
During each wake-up cycle, a charge Qr is used:
•
•
When the device transmits data during WL3 (at 10 dBm), Qt is used:
Qt = WL3 x 48 mA
Example:
•
If no "radio activity": Qr = Σ I ∆t < 8 ms x 0.8 mA + WL1 x 29 mA + [WPER] x 3 µA
If "radio activity": Qr = Σ I ∆t < 8 ms x 0.8 mA + WL1 x 29 mA + WL2 x 29 mA +
[WPER] x 3 µA
–
–
–
With the AT86RF211 transceiver.
–
–
a wireless system must be able to answer maximum 5s after request, but is
interrogated typically once an hour.
the data to be sent = 16 bytes = [16 x 8] = 128 bits at 9600 bits/s => 13 ms
2 AA alkaline batteries (Q = 2.7 A.h) => Qb = 1.3 A.h = 1300 x 3600 x 1000
mA.ms = 4.7 10
the chip will wake-up periodically & send data only on request.
wake-up message (worst case with full Address and Data) = 62 bits =>
6.5 ms
9
mA.ms
AT86RF211 (TRX01)
17