Data detector for uhf rfid tags
AssigneeTexas Instruments Incorporated
InventorsGanesh K. Balachandran, Raymond E. Barnett
Life of this patent
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Abstract
A method of detecting a signal in radio frequency identification (RFID) transponder (FIG. 1) is disclosed. The method includes receiving a signal (FIG. 7) having a first time in a first logic state (high) and having a second time in a second logic state (low). A weight (700, 702) is determined in response to the first time and the second time. An output signal (from A2D) is produced in response to the weight and one of the first and second logic states.
Claims2
In an RFID circuit for receiving a modulated RF signal having an envelope corresponding to digital coding of information, a detector circuit for detecting data contained in the RF signal envelope, comprising:
- a supply voltage terminal;
- a reference voltage terminal;
- a preamplifier circuit having a current source coupled to the supply voltage terminal, and having first and second input transistors coupled to the current source, each input transistor producing respective first and second output signals;
- and
- a dynamic latch circuit coupled to the preamplifier circuit, wherein gain of the preamplifier suppresses offset of the dynamic latch, the dynamic latch having parallel current paths, each current path comprising:
- an input transistor coupled to receive one of the first and second output signals;
- a switching transistor coupled in series with the input transistor, the switching transistor operable to couple the input transistor to the first latch transistor in response to a first logic state of a latch signal;
- a first latch transistor coupled in series with the switching transistor;
- and
- a second latch transistor coupled in series with the first latch transistor.
Dependencies are inferred from the claim text.