Data Sheet

LC840PA
Datasheet
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Power Consumption Notes:
▪ LFRC (0.7 uA) and RTC (0.1uA) running as well as 256k RAM retention (1.4 uA) – This adds to the total of
3.1 uA typical. The RAM retention is 20nA per 4k block (1.28uA), but this can vary to 30nA per 4k block
(1.92uA) which would make the total 3.7uA.
▪ LC840PA PA and LNA and associated circuitry takes the rest.
Note 3
In Deep Sleep (System OFF), everything is disabled, and the only wake-up sources (including NFC to wakeup)
are reset and changes on SIO or NFC pins on which sense is enabled. The current consumption seen is ~2.0 uA
typical in LC840PA modules.
▪ Coming out from Deep Sleep (System OFF) to Standby Doze (System ON Idle) through the reset vector.
Note 4
Average current consumption depends on several factors (including Tx power, VCC, accuracy of 32MHz and
32.768 kHz). With these factors fixed, the largest variable is the Bluetooth LE advertising or Bluetooth LE
connection interval set.
Bluetooth LE Advertising Interval range:
▪ 20 milliseconds to 10240 mS (10485759.375 mS in BT 5.1) in multiples of 0.625 milliseconds.
For a Bluetooth LE advertising event:
▪ The minimum average current consumption is when the advertising interval is large 10240 mS
(10485759.375 mS in BT 5.1) although this may cause long discover times (for the advertising event) by
scanners
▪ The maximum average current consumption is when the advertising interval is small 20 mS
Other factors that are also related to average current consumption include the advertising payload bytes in
each advertising packet and whether it’s continuously advertising or periodically advertising.
Bluetooth LE Connection Interval range (for a peripheral):
▪ 7.5 milliseconds to 4000 milliseconds in multiples of 1.25 milliseconds.
For a Bluetooth LE connection event (for a peripheral device):
▪ The minimum average current consumption is when the connection interval is large 4000 milliseconds
▪ The maximum average current consumption is with the shortest connection interval of 7.5 ms; no slave
latency.
Other factors that are also related to average current consumption include:
▪ Number packets per connection interval with each packet payload size
▪ An inaccurate 32.768 kHz master clock accuracy would increase the average current consumption.
Bluetooth LE Connection Interval range (for a central device):
▪ 2.5 milliseconds to 40959375 milliseconds in multiples of 1.25 milliseconds.
4.2 Peripheral Block Current Consumption
The values below are calculated for a typical operating voltage of 3V.
Table 10: UART power consumption
Parameter
Min
Typ
Max
Unit
WITH
DCDC(REG1)
WITH
LDO(REG1)
UART Run current @ 115200 bps
-
729
951
-
uA
UART Run current @ 1200 bps
-
729
951
-
uA
Idle current for UART (no activity)
-
29
29
-
uA
UART Baud rate
1.2
-
1000
kbps