UM-B-074
DA1468x Range Extender Daughterboard
User Manual
Revision 1.1
17-Apr-2018
CFR0012
19 of 60
© 2018 Dialog Semiconductor
7.1.3.1
Power Modes
The SKY66112-11 FEM supports three different power modes:
●
HPM1:
High Power Mode 1, where VCC2 = 3.0 V, VCC1 = 1.8 V and VDD = 3.0 V @
P
OUT
= +21 dBm, P
IN
= -1 dBm.
●
LPM1:
Low Power Mode 1, where VCC2 = 1.8 V, VCC1 = 1.8 V and VDD = 3.0 V @
P
OUT
= +16 dBm, P
IN
= -3 dBm.
●
LPM2:
Low Power Mode 2, where VCC2 = 1.2 V, VCC1 = 1.8 V and VDD = 3.0 V @
P
OUT
= +13 dBm, P
IN
= -3 dBm (see
Figure 12
).
In the current design due to FCC compliance
5
reasons, Low Power Mode 2 is used. VCC2 voltage
level is connected to V18 and it is configured to 1200 mV using a series resistor R73=16.5
. The
DA14680/681 TX output power is set to -2 dBm and it is programmed using RF_TX_PWR_REG
(0x500020C0).
Figure 12: SKY66112-11 Gain vs. P
OUT
, LPM2
The use of a hardware resistive attenuator between DA14680/681 and SKY66112-11 may be
considered to provide an extra low RF input power range to SKY66112-11 when a lower TX output
power is needed (see
Figure 8
). Of course, addition of the resistive attenuator leads to a current
consumption increment for the same RF power output.
Given the lowest power level that DA14680/681 can provide at the input of the PA which is -4 dBm
and that the PA gain in bypass mode is -2 dB, the Range Extender can deliver a minimum output
power of -6 dBm and a maximum of +13.5 dBm.
5
Emission limitations in restricted area of 2483.5 MHz to 2500 MHz.
