RFM31 Datasheet, PDF (135/137 Pages) –

RFM31
16.Errata Details
1. Description: Some non-standard frequencies are not supported.
Impacts: Operation in frequencies between 240-280 MHz and 480-560 MHz should be avoided.
Workaround: These are non-standard bands and should result in no customer impact; no workaround at this
time.
Resolution: Will be fixed in the next revision.
2. Description: Radio does not return to the low power state when in Low Duty Cycle mode.
Impacts: When using the Low Duty Cycle mode, the radio will not automatically return to the low power state.
Workaround: The radio mode control can be implemented on the external MCU for controlling the RX power
state.
Resolution: Will be fixed in the next revision.
3. Description: Additional tuning steps are required for proper RX mode operation.
Impacts: Tuning can fail if additional steps are not implemented in customer firmware.
Workaround: The following steps should be followed to ensure proper operation:
1. Program desired RX frequency minus 937.5kHz: Program registers 75h, 76h, and 77h
2. Program tune mode: Program register 07h bit 1 (pllon = 1)
3. Disable VCO calibration: Program register 55h bit 0 (skipvco = 1)
4. Program desired RX frequency: Program registers 75h, 76h, and 77h
5. Program RX mode: Program register 07h bit 2 (rxon = 1)
6. Implement normal operation
Resolution: Will be fixed in the next revision
4. Description: Potential modem failure in receive mode with default settings.
Impacts: Under strong blocker conditions, the modem can fail unless the listed workaround is followed.
Workaround: Operate the radio with AFC enabled: Program register 56h to C1h
Resolution: Will be fixed in the next revision.
5. Description: Default register settings for optimal current consumption.
Impacts: Current consumption.
Workaround: Program register 57h bits 2:0 (cdcurr[2:0] = 001), register 59 bit 6 (fbdivhc = 0), register 5Ah bits
1:0 (vcocur[1:0] = 01).
Resolution: Will be fixed in the next revision.
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