HT672A_07 Datasheet, PDF (1/8 Pages) Holtek Semiconductor Inc – 13.56MHz RFID Transponder

HT672A
13.56MHz RFID Transponder
Features
· Low low operating current (15mA @ V_DD=2V)
· Wide range operating voltage
· Battery less RF transponder
· Data transmission in read-only operation
· Max. of 64-bits customer programmable data
· 16-bits CRC error detection code
· OTP data memory
· 13.56MHz carrier frequency
· Output data baud rate: 5kbps (Typ.)
· PWM/ASK modulation
· Built-in voltage limiter
· 8-pin DIP package available for engineering
evaluation - not for volume production
Applications
· Interactive toys
· Security system
· Access control
· Anti-counterfeit for commercial product
General Description
The HT672A is an RF transponder IC with 13.56MHz RF
carrier, which provides a low cost battery less 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.
HT672A 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¢s advanced OTP and low power
technology, HT672A offers a very cost effective solution
for RF contact less 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¢s request.
Block Diagram
H F2
H F1
Rev. 1.10
S y s te m
C lo c k
G e n e ra to r
F re q u e n c y
D r iv e r fS Y S /4
P W M /A S K
M o d u la to r
S h ift
R e g is te r
V C C L im ite r
and
R F L im ite r
D a ta
P r o c e s s in g
D a ta
EPRO M
P ow erO N
R eset
T estand
EPRO M
P r o g r a m m in g
C o n tro l
V P A C LK
1
VDD
VSS
May 17, 2007