User's Manual

DC Power Requirements
A DIVISION OF TRIMBLE
Hardware Overview 29
DC Power Requirements
The module is specified to operate with DC input levels of between 3.3 and 5.5 V. All
specifications are maintained as long as the total input current is below 1 A. At 1 A, the
internal Voltage regulator’s protection circuit allows no more current to be taken in. This
1A current limit will be reached slightly sooner if current is drawn out the Vout line, and the
GPIO lines are supplying current to external circuits.
The most obvious impact of this 1A limit is that the module cannot be operated below 3.7
Volts when the RF power output level is set to 27 dBm. This limit is fully explained in the
next section.
The module will still operate if the DC input Voltage level falls below 3.3 V, but its
specifications are not guaranteed. If the DC input Voltage falls below 3 VDC, a “brown-
out” self-protection function in the processor will gracefully turn the module off so that the
module will not be in an undeterminate state once the voltage is restored.
RF Power Output Impact on DC Input Current and Power
The ThingMagic Nano supports separate read and write power level which are command
adjustable via the MercuryAPI. Power levels must be between:
– Minimum RF Power = 0 dBm
– Maximum RF Power = +27 dBm