WM72016 – Secure F-RAM with Gen-2 RFID and Serial Port

Rev. 1.4

May 2011

Page 3 of 32

FUNCTIONAL DESCRIPTION

The WM72016 is a non-volatile memory device with an industry standard UHF RFID interface that enables

processing data in and out of memory as a generic passive RFID transponder. Unlike other transponder ICs,

the WM72016 transponder IC contains high density symmetric read/write F-RAM memory that enables unique

applications of an RFID solution.

When combined with an appropriate antenna design, WM72016 will power up with energy harvested directly

from the RF field. Following an internally generated reset state, the IC configures itself according to pre-

programmed configuration settings that were stored in F-RAM non-volatile memory at wafer probe, packaged

parts test, or end unit transponder personalization at end-user depot. Configuration settings are read out of

memory and applied prior to enabling data transmission in or out of memory.

As specified in the Gen2 standard, the chip receives and processes commands transmitted by the RFID

interrogator (reader).

All required and most optional commands are supported.

In addition to these,

WM72016 supports a number of custom commands that take advantage of F-RAM‟s unique ultra low power

and symmetrical characteristics.

Referring to Figure 2, the transponder IC‟s consist of an RFID interface, control and authentication logic, F-

RAM memory, and power management unit. The external antenna is connected directly to the RFID interface

where the RF signal is rectified with high efficiency Schottky diode based rectifier. The rectified voltage is

multiplied up within the Schottky array and then regulated to supply power to on-chip resources.

Also included in the RFID Interface is a modulator/demodulator that detects incoming signals and modulates

the input impedance to enable backscattering of returned signals.

The control and authentication logic

processes commands to enable access in and out of F-RAM memory.

Figure 2. Block Diagram

Power

Management

RFID

Interface

Control and

Authentication

Logic

F-RAM Array

(16Kb)

External

MCU

(Optional)