User Manual

ThingMagic Nano User Guide 15
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Note that there is no industry standard for the reading success rate a module must achieve to be credited
with operating at a specific receive level. The sensitivity values in the table reflect a very high read success
rate (greater than 90%). Tags typically will begin to respond sporadically at receive levels that are 5 dB
lower than the values shown in this table.
Receiver Adjacent Channel Rejection
ThingMagic Nano receives signals that are centered at +250 kHz from its own carrier. The width of the
receive filter is adjusted to match the “M” value of the signal being sent by the tag. An M value of 2 requires
the widest filter and an M value of 8 requires the narrowest filter. If operating in an environment where
many readers are present, observe the performance of one reader as the other readers are turned on and
off. If the performance improves when the other readers are turned off, then the system may be
experiencing reader-to-reader interference. This reader-to-reader interference will be minimized by using
the highest “M” value that still achieves the tag read rates required by the application.
Environmental Specifications
Thermal Considerations
The module will operate within its stated specifications over a temperature range of -40°C to +60°C,
measured at the ground plane that the ThingMagic Nano module is soldered to.
It may be safely stored in temperatures ranging from -40°C to +85°C.
Thermal Management
Heat-sinking
For high duty cycles, it is essential to use a surface mount configuration where all edge vias are soldered to
a carrier or mother board, with a large area of ground plane, that will either radiate heat or conduct the heat
to a larger heat-sink. A high density of PCB vias from the top to bottom of the board will efficiently conduct
heat to a bottom mount heatsink. Often the weak link in thermal management design is not the thermal
interface from the Nano to the heat-sink, but rather the thermal interface from the heat-sink to the outside
world.
Duty Cycle
If overheating occurs, try reducing the duty cycle of operation. This involves modifying the RF On/Off (API
parameter settings /reader/read/asyncOnTime and asyncOffTime) values. Start with 50% duty cycle using
250ms/250ms On/ Off.
If your performance requirements can be met, a low enough duty cycle can result in no heat sinking
required. With adequate heat sinking you can run continuously at 100% duty cycle.
Temperature Sensor
EU and India (865 to 868 MHz)
8 -60 dBm
4 -58 dBm
2 -49 dBm
Sensitivity for Region and “M” Value
Region “M” Value Sensitivity