HT672B Datasheet, PDF (1/8 Pages) Holtek Semiconductor Inc – 13.56MHz RFID Transponder

HT672B
13.56MHz RFID Transponder
Features
· Wide range operating voltage
· Batteryless RF transponder
· Data transmission in read-only operation
· 6-bits sync + 32-bits data + 8-bits CRC
· OTP data memory
Applications
· Interactive leisure products
· Security system
· Access control
· Anti-counterfeit devices
· 13.56MHz carrier frequency
· Output data baud rate: 10kbps at V_DD=3V
· PWM/ASK modulation
· Built-in voltage limiter
· 8-pin DIP package
· Material management
· Animal management
· Personnel working time record
· Car park monitoring system
General Description
The HT672B is a RF transponder IC operating with
13.56MHz RF carrier, which provides a low cost
batteryless transponder solution with the addition of
merely an external inductor. The inductor and internal
capacitor form a LC tank which inducing voltage from
the radiated 13.56MHz carrier signal generated from the
reader antenna. HT672B 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 response signal(pre-programmed in the OTP
memory) is serial transmitted out. The response data is
transmitted 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 40 bits. One
Time Programmable memory (OTP) (up to 32 bits re-
served for customer) in the chip, with a 8-bits checksum
code. The effective detection range for a small sized an-
tenna is 2cm~10cm which is dependent on antenna for-
mat & reader design. The larger the antenna loop used
the longer the detection range. It is advisable to use
larger antenna to attain a 15cm detection range. Imple-
menting Holtek¢s advanced OTP and low power tech-
nology, HT672B offers a very cost effective solution for
RF contactless detection system. A code area of
32-bits(max.) wide is provided so customers can pro-
gram the device using the specified programmer sup-
plied by Holtek. The pre-programmed Ics are also
available upon customer¢s request.
Block Diagram
HF
S y s te m
V C C L im ite r
C lo c k
and
VDD
G e n e ra to r
R F L im ite r
F re q u e n c y
D a ta
H F1
D r iv e r f/4
P r o c e s s in g
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
T e s t B lo c k
VSS
V P P C LK
Rev. 1.10
1
November 23, 2004