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Figure 4: BLE121LR TX peak current as a function of hardware.xml TXP setting (Example:

<txpower

power="9" bias="5" />)

4.4.1 Current Consumption When Using TPS62730 DCDC Converter

TPS62730 DCDC converter provides 20% reduction to the peak current drawn from 3.0V supply and 15%

reduction to the peak current drawn from 2.7V supply. This is achieved by converting higher power supply

down to 2.1V supply with a switching mode regulator. The module turns the DCDC on when the processor is

active and off (by-pass mode) when the processor is not active.

Because the TX power of BLE121LR depends on the supply voltage, the TX power is reduced when using

TPS62730 DCDC converter. The reduced TX power in turn reduces the peak current drawn by the module.

Thus when using TPS62730 with BLE121LR from 3.0V supply, the peak current is reduced in total by:

•

~4 mA because of lower TX power

•

-20% because of the switching mode regulator converting from 3.0V down to 2.1V

➔ Peak current drawn from 3.0V supply in total (Max TXP, slow clock enabled):

(36 mA

– 4 mA) * 0.8 = 25.6 mA

4.5 RF Characteristics

Rating

Min

Typ

Max

Unit

Transmit power

8

dBm

Transmit power variation within BT band

1

1.8

dB

Transmit power variation within the

temperature range

+/-1.5

dB

Sensitivity (Default, high gain mode, PER

30.8%)

-98

dBm

Sensitivity (standard gain mode, PER

30.8%) (*

-92

dBm

*) Standard gain mode can be set using an API command. Please refer to the Bluetooth Low Energy Software

API Reference document.

Figure 5: BLE121LR RF characteristics