CC2591 Datasheet, PDF (9/18 Pages) Texas Instruments – 2.4-GHz RF Front End

CC2591
www.ti.com ........................................................................................................................................................ SWRS070A – MARCH 2008 – REVISED JUNE 2008
Controlling the Output Power from CC2591
The output power of CC2591 is controlled by controlling the input power. The CC2591 PA is designed to work in
compression (class AB), and the best efficiency is reached when a strong input signal is applied.
Input Levels on Control Pins
The four digital control pins (PAEN, EN, HGM, RXTX) have built-in level-shifting functionality, meaning that if the
CC2591 is operating from a 3.6-V supply voltage, the control pins will still sense 1.6-V - 1.8-V signals as logical
‘1’.
An example of the above would be that RXTX is connected directly to the RXTX pin on CC24xx, but the global
supply voltage is 3.6 V. The RXTX pin on CC24xx will switch between 0 V (RX) and 1.8 V(TX), which is still a
high enough voltage to control the mode of CC2591.
The input voltages should however not have logical ‘1’ level that is higher than the supply.
Connecting CC2591 to a CC24xx Device
Table 3. Control Logic for Connecting CC2591 to a CC24xx Device
PAEN = EN
0
1
1
1
RXTX
X
0
0
1
HGM
X
0
1
X
MODE OF OPERATION
Power Down
RX Low Gain Mode
RX High Gain Mode
TX
C11/C12
VDD VDD
C101/C102
VDD
C161
VDD
C131/C132
= TLINE inductor
CC243x
L111
L112
C113
C112
C111
ANT
CC2591
RF_P ^RRFF__PP
RXTX ^RRXXTTXX
RF_N ^RRFF__NN
PAEN
EN
HGM
RF_P
TXRX_SWITCH
RF_N
RREG_OUT (CC243x)
R151
Connected to
Alternativiely
VDD/GND/MCU/RXTX ^{from MCU}
Figure 10. CC2591 + CC24xx Application Circuit
Copyright © 2008, Texas Instruments Incorporated
Product Folder Link(s): CC2591
Submit Documentation Feedback
9