MRF24XA_15 Datasheet, PDF (224/258 Pages) Microchip Technology – Low-Power, 2.4 GHz ISM-Band IEEE 802.15.4™ RF

MRF24XA
9.9 Physical Transmissions
MCU sets TXST and transmission starts when TXST is
set to ‘1’. TXMAIF, TXSFDIF and RXSFDIF flags are
handled. RXSFDIF is handled even with ACK. External
PA/LNA is automatically handled.
For more information on this mode, see Section 9.13
“External Power Amplifier (PA)/Low-Noise Amplifier
(LNA)”.
Channel, data rate and link adaptation is based on
retransmission, and the information is from the
receiver.
REGISTER 9-25: TXPOW (TRANSMIT POWER CONFIGURATION REGISTER)
R/W-000
R/W-11111
CHIPBOOST<2:0>
bit 7
TXPOW<4:0>
ADDRESS 0x3A
bit 0
Legend: R = Readable bit W = Writable bit
-n = Value at POR
‘1’ = Bit is set
r = Reserved
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-5
bit 4-0
CHIPBOOST<2:0>: TX Chip Boosting Field bits
This field modifies the spectrum of the OQPSK transmission.
TXPOW<4:0>: TX Power Register Field bits
This field enables configuring the TX power ranging from -19 to 1 dBm. Encoding:
11111 = +1 dBm
•
•
•
00001 = -19 dBm
00000 = PA OFF
FIGURE 9-5:
OUTPUT POWER IN
FUNCTION OF TXPOW
FIGURE 9-6:
TX CURRENT IN
FUNCTION OF TXPOW
1
0
-5
-10
-15
-20
6
11
16
21
26
31
TXPOW register (decimal)
31
26
21
16
11
1
6
11
16
21
26
31
TXPOW register (decimal)
Note: Some variance is expected due to a differ-
ent matching network.
DS70005023C-page 224
Preliminary
 2015 Microchip Technology Inc.