2003 Microchip Technology Inc.
DS21308E-page 1
MCRF202
Features
External sensor input
Data polarity changes with sensor input condition
Read-only data transmission
96- or 128-bits of factory programming user
memory (also supports 48- and 64-bit protocols)
Operates up to 400 kHz carrier frequency
Low-power operation
Modulation options:
- ASK, FSK, PSK
Data Encoding options:
- NRZ Direct, Differential Biphase Manchester
Biphase
Die, Wafer, PDIP or SOIC package option
Factory programming and device serialization
Applications
Insect control
Industrial tagging
Package Type
PDIP/SOIC
Description
The MCRF202 is a passive Radio Frequency Identifi-
cation (RFID) device that provides an RF interface for
reading the contents of a user memory array. This
device is specially designed to detect the logic state of
an external sensor, and alters its data transmissions,
based on the condition of the sensor input. The device
outputs a normal bit data stream if the sensor input has
a logic ‘
1
’ state, but outputs an inverted data stream for
a logic ‘
0
’ state. In this way, the reader can monitor the
state (condition) of the external sensor input by
detecting whether the data from the device is a normal
or inverted data stream.
The device is powered by rectifying the incoming RF
carrier signal that is transmitted from the reader. When
the device develops sufficient DC voltage, it transmits
the contents of its memory array by modulating the
incoming RF carrier signal. The reader is able to detect
the modulation and decodes the data being transmit-
ted. Code length, modulation option, encoding option,
and bit rate are set at the factory to fit the needs of
particular applications.
The MCRF202 is available in die, wafer, PDIP and
SOIC packages. The encoding, modulation, bit rate
options, and data fields are specified by the customer
and programmed by Microchip Technology Inc. prior to
shipment. See Technical Bulletin TB023 for more
information on factory serialization (SQTP).
MCRF202
Reader
RF
Signal
Data
External
Sensor
Switch
V
A
NC
V
B
1
2
3
4
8
7
6
5
TEST
SENSOR
NC
V
SS
V
CC
125 kHz Passive RFID Device with Sensor Input