Holtek BC45B4523, Руководство пользователя, Страница: 46 / 96

Rev. 1.20 46 October 28, 2020
BC45B4523
The driving behaviour of the transmitter is defined by the register TxControl (Sector0-0x11). By configuring the
Tx1Inv, Tx2Inv, Tx2Cw, Tx2RFEn and Tx1RFEn bits, the driver can provide a differential modulated output,
a single-ended modulated output or a plain carrier with a baseband signal for driving external circuitry. Setting
the 100ASK bit makes the transmitter stops driving carrier during the modulation period. The behaviours of the
transmitter in all possible combinations are shown in “TXn Driver Behaviours on TxControl Combinations” table
for pin TX1 and pin TX2 respectively.
• TxControl Register
This register controls the logical behaviour of the transmitter driver on pin TX1 and TX2.
Address Bit 7 6 5 4 3 2 1 0
Sector0-0x11
Name Tx1Inv ModulatorSource[1:0] 100ASK Tx2Inv Tx2Cw Tx2RFEn Tx1RFEn
Type R/W R/W R/W R/W R/W R/W R/W
Reset
Value
0 0 0 1 1 0 0 0
Configuration
Input
(ENV_Int)
Output
Mode
Tx1RFEn 100ASK Tx1Inv TX1 Logic TX1 Conductance
0 X 0 0 0 Short to T_V
SS
Shutdown or
Connect to external Circuit
0 X 0 1 1 TxCfgCW
0 X 1 0 1 TxCfgMOD
Shutdown
0 X 1 1 1 TxCfgCW
1 0 0 0 RF TxCfgMOD
Modulation
10-60% ASK
1 0 0 1 RF TxCfgCW
1 0 1 0 RF_N TxCfgMOD
1 0 1 1 RF_N TxCfgCW
1 1 0 0 0 Short to T_V
SS
Modulation
100% ASK
1 1 0 1 RF TxCfgCW
1 1 1 0 1 TxCfgCW
1 1 1 1 RF_N TxCfgCW
TX1 Driver Behaviours on TxControl Combinations
Configuration
Input
(ENV_Int)
Output
Mode
Tx2RFEn 100ASK TX2Cw Tx2Inv
TX2
Logic TX2 Conductance
0 X 0 0 0 0 Short to T_V
SS
Shutdown or
Connect to external Circuit
0 X 0 0 1 1 TxCfgCW
0 X 0 1 0 1 TxCfgMOD
Shutdown
0 X 0 1 1 1 TxCfgCW
0 X 1 0 0 0 Short to T_V
SS
0 X 1 0 1 0 Short to T_V
SS
0 X 1 1 0 1 TxCfgCW
0 X 1 1 1 1 TxCfgCW
1 0 0 0 0 RF TxCfgMOD
Modulation
10-60% ASK
1 0 0 0 1 RF TxCfgCW
1 0 0 1 0 RF_N TxCfgMOD
1 0 0 1 1 RF_N TxCfgCW