HT6720
13.56MHz RFID Transponder
Features
路
Very low operating current (4mA @ V
DD
=3V)
路
Wide range operating voltage
路
Batteryless RF transponder
路
Data transmission in read-only operation
路
Max. of 64-bits customer programmable data
路
16-bits CRC error detection code
路
OTP data memory
路
13.56MHz carrier frequency
路
Output data baud rate: 4kbps (Typ.) @ V
DD
=3V
路
PWM/ASK modulation
路
Built-in voltage limiter
Applications
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Interactive leisure products
路
Security system
路
Access control
路
Anti-counterfeit devices
路
Material management
路
Animal management
路
Personnel working time record
路
Car park monitoring system
General Description
The HT6720 is an RF transponder IC with 13.56MHz RF
carrier, which provides a low cost batteryless tran-
sponder solution when combined with an external in-
ductor. The inductor and internal capacitor form an LC
tank which induce voltage from the radiated 13.56MHz
carrier signal generated from the reader antenna.
HT6720 has a built-in low power RC oscillator which is
activated if the induced carrier field strength is high
enough to supply the operating current and the re-
sponse signal (pre-programmed in the OTP memory) is
serially transmitted out. The response data is transmit-
ted using PWM/ASK modulation. Modulation of
13.56MHz is accomplished by damping the LC tank with
a fixed baud rate.
The transmission information is stored in a 96 bits one
time programmable memory OTP, with a 16-bit CRC
code (up to 64 bits reserved for customer). The effective
detection range for a small sized antenna is 2cm~10cm
which is dependent on antenna format & reader design.
The larger the antenna loop used the longer the detec-
tion range. It is advisable to use larger antenna to attain
a 15 cm detection range.
Implementing Holtek壟s advanced OTP and low power
technology, HT6720 offers a very cost effective solution
for RF contactless detection system.
A code area of 64-bits (max.) wide is provided so cus-
tomers can program the device using the specified pro-
grammer supplied by Holtek. The pre-programmed ICs
are also available upon customer壟s request.
Block Diagram
H F 2
S y s te m
C lo c k
G e n e ra to r
V C C
L im ite r
a n d
R F L im ite r
V D D
H F 1
D a ta
P r o c e s s in g
P o w e r O N
R e s e t
T e s t a
E P R O
P ro g ra m
C o n tr
n d
M
m in g
o l
P W M /A S K
M o d u la to r
S h ift
R e g is te r
D a ta
E P R O M
V S S
V P A
C L K
Rev. 1.00
1
August 13, 2001
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