FEATURES
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MCRF450
PACKAGE TYPES
PDIP/SOIC
ANT_A
NC
ANT_B
CLK
13.56 MHz Read/Write Passive RFID Device
Carrier Frequency: 13.56 MHz
Data rate for reading: 70 kHz
Contactless read and write
1024 bits (32 blocks) of total memory
864 bits of user programmable memory
User controlled write protection of each block
Manchester coding protocol with CRC for reading
RF field gaps and 1-of-16 PPM with CRC
for writing
Built-in anticollision algorithm for reading and writ-
ing multiple tags in the same RF field
Three pads for external antenna circuit
Factory programmed unique 32-bit tag ID
Interrogator talks first (ITF) or tag talks first (TTF)
operation
Fast and normal modes for data transmission
Anti-tearing feature
Full 32-bit EAS support
Very low power CMOS design
Die, wafer, COB module, PDIP, or SOIC package
options
1
2
3
4
8
7
6
5
V
DD
FCLK
NC
V
SS
DESCRIPTION
The MCRF450 is a contactless read/write passive
RFID device that is optimized for 13.56 MHz RF carrier
signal. The device needs an external LC resonant cir-
cuit to communicate with interrogator wirelessly. The
device is powered remotely by rectifying an RF signal
that is transmitted from the interrogator, and transmits
or updates its contents of memory based on com-
mands from the interrogator.
The device is engineered to be used effectively for item
level tagging applications such as retail and inventory
management, where a large volume of tags are read
and written in the same interrogator field.
The device contains 32 blocks of EEPROM memory.
Each block consists of 32 bits. The first three blocks (B0
- B2: 96 bits) are allocated for device operation, the
next 27 blocks (B3 - B29: 864 bits) are for user data,
and the remaining 2 blocks (B30 - B31: 64 bits) are
reserved for future use. The 864 (B3 - B29) user bits
are contactlessly read or written block-wise by interro-
gator commands. All blocks except bits 30 and 31 in
block 0 are write protectable.
The device has two operational modes depending on
the conditions of talk first (TF) and fast read (FR) bits.
These modes are: “tag talks first” (TTF) and “interroga-
tor talks first” (ITF) modes. The device operates in TTF
mode if both TF and FR bits are set. In this mode, the
device transmits its fast read response data (96 bits in
default) as soon as it is energized, and waits for the
next commands. The device operates in the “interroga-
tor talks first” mode, if the TF bit is cleared. In this
mode, the device requires an interrogator command
before it sends any data.
©
2000 Microchip Technology Inc.
Preliminary
DS40232A-page 1
MCRF450
The device uses an internal oscillator for data timing of
the read operation. The data rate for reading is 70 kHz
and uses Manchester format. The communication
between the interrogator and the device takes place
asynchronously.
The interrogator sends commands to the device by
amplitude modulating its RF carrier signal. 1-of-16
Pulse Position Modulation (PPM) and specially timed
gap pulses are used for the modulation of the carrier
signal. The device includes a detection circuit to detect
these interrogator commands.
To enhance the detection accuracy in the device, the
interrogator sends a time reference signal (time calibra-
tion pulse) to the device followed by the command and
programming data. The time reference signal is used to
calibrate timing of the internal decoder of the device.
ing) the modulation transistor. This loading and unload-
ing of the carrier appears as amplitude modulation at
the interrogator’s receiver.
The device includes a unique anticollision algorithm to
be read or written effectively in multiple tag environ-
ments. To minimize data collision, the algorithm utilizes
time division multiplexing of the device response.
Therefore each device can communicate with the inter-
rogator in a different time slot. The devices in the inter-
rogator’s RF field remain in a non-modulating condition
if they are not in the given time slot. This enables the
interrogator to communicate with the multiple devices
one at a time without data collision. The details of the
algorithm are described in Section 4.0.
To enhance data integrity for writing, the device
includes an anti-tearing feature. This anti-tearing fea-
ture provides verification of data integrity for incomplete
write cycles due to failed communication from the inter-
rogator to the device during the write sequences.
APPLICATION
Read/Write
Command
Interrogator
(reader/writer)
C
Data
L1
L2
Ant. A
MCRF450
Ant. B
V
SS
The device needs an external LC resonant circuit that
is connected between antenna A, antenna B, and Vss
pads. This external LC resonant circuit must be tuned
to the carrier frequency of the interrogator for maximum
performance.
When a tag (device with the external LC resonant cir-
cuit) is brought to the interrogator’s RF field, it develops
an RF voltage across the external circuit. The device
rectifies the RF voltage and develops a DC voltage
(V
DD
). The device becomes functional as soon as V
DD
reaches the operating voltage level.
The device sends data to the interrogator by turning on/
off the internal modulation transistor. This internal mod-
ulation transistor is located between antenna B and
Vss. The modulation transistor has very small turn-on
resistance between Drain (Antenna B) and Source
(Vss) terminals during its turn-on time.
When the modulation transistor turns-on, the external
circuit component between antenna B and Vss, that is
in parallel with the modulation transistor, is shorted due
to the low turn-on resistance. This results in a change
of the LC value of the circuit. As a result, the circuit no
longer resonates at the carrier frequency of the interro-
gator, therefore the voltage across the circuit is mini-
mized. This condition is called cloaking.
When the modulation transistor turns-off, the circuit
resonates at the carrier frequency of the interrogator,
and develops maximum voltage. This condition is
called uncloaking. Therefore, the data is sent to the
interrogator by turning-on (cloaking) and off (uncloak-
DS40232A-page 2
Preliminary
©
2000 Microchip Technology Inc.
MCRF450
1.0
ELECTRICAL CHARACTERISTICS
ABSOLUTE RATINGS
Parameters
Coil current into coil pad
Maximum power dissipation
Ambient temperature with power applied
Assembly temperature
Storage temperature
Note:
TABLE 1-1:
Symbol
Min.
—
—
-40
—
-65
Max.
40
1
125
300
150
Units
mA
W
°C
°C
°C
Conditions
Peak-to-Peak coil cur-
rent
I
PP
_
AC
P
MPD
T
AMB
T
ASM
T
STORE
< 10 Sec
Stresses above those listed under “Maximum ratings” may cause permanent damage to the device. This is a stress rating only and func-
tional operation of the device at those or any other conditions above those indicated in the operational listings of this specification is not
implied. Exposure to maximum rating conditions for extended periods may affect device reliability.
TABLE 1-2:
DC CHARACTERISTICS
Tamb = -20
o
C to 70
o
C
All parameters apply
Commercial (C):
across the specified
operating ranges,
unless otherwise noted.
Parameters
Reading voltage
Operating current in
normal mode
Operating current in
fast mode
Writing current
Writing voltage
Modulation resistance
Symbol
V
DDR
I
OPER
_
N
I
OPER
_
F
I
WRITE
V
WRITE
R
M
Min.
2.4
—
—
—
2.4
—
Typ.
—
7
TBD
—
—
3
Max.
—
10
—
50
—
4
Units
V
µA
µA
µA
Vdc
Ω
Conditions
V
DD
voltage for reading at 25°C
V
DD
= 2.4 V during reading at 25°C
V
DD
= 2.4 V during reading at 25°C
At 25°C
At 25°C
DC turn-on resistance between
Drain and Source terminals of the
modulation transistor
©
2000 Microchip Technology Inc.
Preliminary
DS40232A-page 3
MCRF450
TABLE 1-3:
AC CHARACTERISTICS
Tamb = -20
o
C to 70
o
C
All parameters apply across Commercial (C):
the specified operating
ranges, unless otherwise
noted.
Parameters
Carrier frequency
Coil voltage during reading
Coil detuning voltage
Interrogator data (ITD)
rate_normal
Interrogator data (ITD)
rate_fast
Device data rate
Modulation depth of 1-of-16
PPM
Pulse width of 1-of-16 PPM
for normal mode
Pulse width of 1-of-16 PPM
for fast mode
Symbol width of 1-of-16
PPM for normal mode
Symbol width of 1-of-16
PPM for fast mode
Gap pulse width of Fast
Read command
EEPROM (Memory) Writing
Time
Command Decode Time
Symbol
F
c
V
PP
_
AC
V
DETUNE
F
ITD
_
NORM
F
ITD
_
FAST
F
DVD
M
DEPTH
_
PPM
PW
PPM
_
N
PW
PPM
_
F
SW
PPM
_
N
SW
PPM
_
F
GPW_
FR
T
WRITE
T
DECODE
Min.
—
4
—
—
—
58
—
—
—
—
—
—
—
—
Typ.
13.56
—
TBD
1.4286
25
70
100
175
10
2.8
160
175
5
TBD
Max.
—
—
—
—
—
82
—
—
—
—
—
—
—
—
Units
MHz
V
PP
V
PP
kHz
kHz
kHz
%
µs
µs
ms
µs
µs
ms
µs
Conditions
Peak-to-Peak AC voltage
across the coil during reading
Coil voltage at which the limit-
ing circuit becomes active
Both normal and fast modes
See Figure 4-3 and Table 4-7
for details.
See Figure 4-3 and Table 4-7
for details.
See Figure 4-3 and Table 4-7
for details.
At 25°C, write time for a 32-bit
block.
Note
Time delay between end of
command symbol and start of
the device response.
Time slot
Listening Window
Modulation depth of Fast
Read command
Command Duration of Fast
Read command (FRR and
FRB)
Input impedance A
T
SLOT
T
LW
M
DEPTH
_
FRR
T_CMD_
FRR
TBD
—
—
2.5
1
100
1.575
2.925
TBD
—
—
ms
ms
%
ms
175
µs
/pulse position x 9
pulse positions = 1.575 ms
Input impedance between
antenna pad A and V
SS
, at
13.56 MHz with modulation
transistor off (no external coils)
Input impedance between
antenna pad B and V
SS
, at
13.56 MHz with modulation
transistor off (no external coils)
For T < 120°C
At 25°C
Zin_A
—
TBD
—
Ω
Input impedance B
Zin_B
—
TBD
—
Ω
Data retention
Endurance
Note:
—
—
200
1
—
—
—
—
Years
Million
Cycles
Writing time starts at the end of the last command symbol.
DS40232A-page 4
Preliminary
©
2000 Microchip Technology Inc.
MCRF450
TABLE 1-4:
Pad Name
Ant. Pad A
Ant. Pad B
V
SS
V
DD
CLK
F
CLK
Note:
PAD COORDINATES (MICRONS)
Lower
Left X
—
—
—
—
—
—
Lower
Left Y
—
—
—
—
—
—
Upper
Right X
—
—
—
—
—
—
Upper
Right Y
—
—
—
—
—
—
Passivation Openings
Pad Width
89.00
89.00
89.00
89.00
89.00
89.00
Pad Height
89.00
89.00
89.00
89.00
89.00
89.00
Pad
Pad
Center X Center Y
—
—
—
—
—
—
—
—
—
—
—
—
All coordinates are referenced from the center of the die. The minimum distance between pads (edge to
edge) is 10 mil.
FIGURE 1-1:
DIE LAYOUT
Ant. Pad A
V
DD
F
CLK
FIGURE 1-2:
DIE DIMENSION
Top View
Ant B
Ant A
L1
C
MCRF450
CLK
V
DD
L2
Ant. Pad B CLK
Vss
V
SS
F
CLK
L1: Antenna Coil A
L2: Antenna Coil B
C: Capacitor
Note: Substrate = V
SS
TABLE 1-5:
Name
PAD FUNCTION TABLE
Function
Ant. Pad A Connected to antenna coil L1
Ant. Pad B Connected to antenna coils L1 and L2
V
SS
V
DD
CLK
F
CLK
Note:
Connected to antenna coil L2
Device ground during test mode
DC voltage supply for testing and con-
tact programing
Main clock for device,
Note
Test input for fast clock mode,
Note
Leave floating or connect to V
SS
.
©
2000 Microchip Technology Inc.
Preliminary
DS40232A-page 5
