Controlling the Output Power from CC2591

RF_P

RXTX

RF_N

RF_P

TXRX_SWITCH

RF_N

CC243x

RREG_OUT (CC243x)

Connected to

VDD/GND/MCU/RXTX

Alternativiely

from MCU

RF_P

RXTX

RF_N

= TLINE inductor

CC2591

ANT

PAEN

EN

HGM

VDD

VDD VDD

VDD

RF_P

RXTX

RF_N

L112

C113

C111

L111

C112

C161

C11/C12

C101/C102

C131/C132

R151

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

RXTX

HGM

MODE OF OPERATION

0

X

X

Power Down

1

0

0

RX Low Gain Mode

1

0

1

RX High Gain Mode

1

1

X

TX

Figure 10. CC2591 + CC24xx Application Circuit

Copyright © 2008, Texas Instruments Incorporated

Submit Documentation Feedback

9

Product Folder Link(s): CC2591