Semtech LR1121 - Settcxomode; Table 6-2: Settcxomode Command; Table 6-3: TCXO Supply Voltage Programming Values

LR1121
User Manual Rev 1.1
UM.LR1121.W.APP Mar 2023
47 of 130
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6.3.2 SetTcxoMode
Configures the chip for a connected TCXO.
The TCXO must be configured using SetTcxoMode(...) before calling GetTemp().
• RegTcxoTune tunes the output voltage on the TCXO supply pin VTCXO, according to Table 6-3: TCXO Supply Voltage
Programming Values.
• Delay represents the maximum duration for the 32MHz oscillator to start and stabilize (in 30.52us steps). If the 32MHz
oscillator from the TCXO is not detected internally at the end the delay period, the device internal firmware triggers a
HF_XOSC_START_ERR error.
 0: Disables TCXO mode (default value).
 1: Sets TCXO mode. A complete Reset of the chip is required to get back to normal XOSC operation.
Command only operates in Standby RC mode, otherwise it returns CMD_FAIL on the next GetStatus() command.
Table 6-2: SetTcxoMode Command
Byte 0 1 2 3 4 5
Data from Host 0x01 0x17 RegTcxoTune
Delay
(23:16)
Delay
(15:8)
Delay
(7:0)
Data to Host Stat1 Stat2
IrqStatus
(31:24)
IrqStatus
(23:16)
IrqStatus
(15:8)
IrqStatus
(7:0)
Table 6-3: TCXO Supply Voltage Programming Values
RegTcxoTune TCXO Supply Voltage (typ)
0x00 1.6 V
0x01 1.7 V
0x02 1.8 V
0x03 2.2 V
0x04 2.4 V
0x05 2.7 V
0x06 3.0 V
0x07 3.3 V