HT672B
13.56MHz RFID Transponder
Block Diagram
Rev. 1.10
1
November 23, 2004
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
13.56MHz carrier frequency
Output data baud rate: 10kbps at V
DD
=3V
PWM/ASK modulation
Built-in voltage limiter
8-pin DIP package
Applications
Interactive leisure products
Security system
Access control
Anti-counterfeit devices
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.
V P P
C L K
H F
H F 1
V D D
V S S
P W M / A S K
M o d u l a t o r
S h i f t
R e g i s t e r
D a t a
S y s t e m
C l o c k
G e n e r a t o r
V C C L i m i t e r
a n d
R F L i m i t e r
D a t a
P r o c e s s i n g
F r e q u e n c y
D r i v e r f / 4
T e s t B l o c k
Pin Assignment
Pad Assignment
Chip size: 36.4
36.4 (mil)
2
* The IC substrate should be connected to VSS in the PCB layout artwork.
Pad Coordinates
Unit:
mm
Pad No.
X
Y
Pad No.
X
Y
1
-252.875
303.663
4
247.074
-297.912
2
-252.875
-298.537
5
238.174
284.663
3
112.975
-314.687
6
126.674
284.663
Pad Description
Pad
No.
Pad
Name
I/O
Internal
Connection
Description
1
HF
I/O
CMOS
Connect to an antenna coil for normal operation. Open for data programming.
2
HF1
I/O
CMOS
Connect to an antenna coil for normal operation. Data I/O for programming.
3
VSS
Negative power supply, ground
4
CLK
I
CMOS
Open for normal operation. Clock input for programming.
5
VPP
I
Open for normal operation. High voltage supplies input for programming.
(Suggest 12.5V for programming)
6
VDD
Open for normal operation, +6V supply input for programming.
HT672B
Rev. 1.10
2
November 23, 2004
1
2
3
4
8
7
6
5
H F
N C
N C
H F I
V C C
V P P
C L K
G N D
H T 6 7 2 B
8 D I P - A
( 0 , 0 )
H F
H F 1
G N D
C L K
V C C
V P P
1
2
3
4
5
6
Absolute Maximum Ratings
Supply Voltage (VDD) ............................................5.5V
Storage Temperature ...........................
-50C to 125C
Supply Voltage (VPA) ..........................................12.5V
Operating Temperature ..............................0
C to 70C
Input Voltage .............................V
SS
-0
.
3V to V
DD
+0.3V
Note: These are stress ratings only. Stresses exceeding the range specified under
Absolute Maximum Ratings may
cause substantial damage to the device. Functional operation of this device at other conditions beyond those
listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliabil-
ity.
Electrical Characteristics
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
V
DD
Conditions
V
DD
Operating Voltage
V
DD
pad voltage
2
3
4
V
I
DD
Operating Current
2V
15
mA
I
DD
Operating Current
3V
400
mA
R
m
Modulation Resistance
3.3V
320
W
V
LCL
LC Input Limiter Voltage
6.5
V
B
R
Output Data Baud Rate
3V
V
DD
vs V
SS
5
10
15
Kbps
HT672B
Rev. 1.10
3
November 23, 2004
Functional Description
Operation Concept
The reader transmits a 13.56MHz carrier signal from its
antenna, the LC tank on the transponder side converts
the carrier energy to voltage form and supply to the tran-
sponder chip with an internal pump circuit. If the induced
energy is high enough, the pumped voltage reaches the
break-in voltage of internal RC-oscillator, the tran-
sponder is actuated to transmit its internal data serially
by means of damping the LC tank.
The reader receiving the transponder
s data by means
of detecting the energy variation on it
s own antenna,
and recognize the information with a microcontroller.
The HT672B has a built-in internal Voltage Limiter to
prevent excess power supply and RF levels induced by
the LC tank from damaging the device or causing the
device to function abnormally.
A total of 40 bits of O
TP memory space is provided,
from which 20 bits wide are customer programmable,
which can be programmed using the specified program-
mer supplied by Holtek. The pre-programmed Ics are
also available upon customer
s request.
H T 6 7 2 B
E n e r g y
D a t a
R F o s c
&
C o n t r o l l e r
T r a n s p o n d e r
R e a d e r
Timing & Code Package
Application Circuits
Tag
A tag consists of a PCB (or Mylar film) with printed coil, HT672B and a housing. The housing can be of various shapes.
Note:
The value of the antenna inductance is 11
mH, however the optimum value will be changed slightly due to the
variation of the internal resonance capacitor (10pF typically) during process.
For more application information about the reader, refer to Holtek
s 13.56MHz RF ID reader data.
2-chip Solution
HT672B
Rev. 1.10
4
November 23, 2004
O n e P a c k a g e F o r m a t
P r o d u c t
C o d e
C u s t o m e r
I D
( 1 2 b i t s )
( 2 0 b i t s )
S y n c . D a t a
( 8 b i t s )
C h e c k
S u m
Code Package
A total of 40 bits information can be stored in the HT672B,
from which 20 bits are customer programmable.
Sync. data: Including 4 bits
(which low/high duty length is 50%)
Mark data: 2 bits (always high signal).
Customer ID: This 12-bit wide code is not customer
programmable and is supplied together with the data
writer after register to Holtek. The writer generates the
code automatically.
Product code: Storing the contents of the user ID
number or data.
Check sum: A 8 bits of checksum code is generated
automatically by the writer.
H F
H F 1
H T 6 7 2 B
P C B
T a g H o u s i n g
H T 6 7 2 B
E n e r g y
D a t a
H o l t e k T r a n s p o n d e r S o l u t i o n
H o l t e k R e a d e r S o l u t i o n
O t h e r C o n t r o l l e r
R F o s c
&
R e c e i v e r
D a t a
D e c o d e
&
S y s t e m
C o n t r o l
S p e c i a l
P u r p o s e
C o n t r o l l e r
H o l t e k l o w c o s t M C U :
H T 4 8 R 0 5 A - 1 / H T 4 8 R 0 6 A - 1
A N T
A N T
1-chip Solution (I)
1-chip Solution (II)
HT672B
Rev. 1.10
5
November 23, 2004
H T 6 7 2 B
E n e r g y
D a t a
H o l t e k T r a n s p o n d e r S o l u t i o n
H o l t e k R e a d e r S o l u t i o n
R F o s c
&
R e c e i v e r
D a t a
D e c o d e
&
S y s t e m
C o n t r o l
H o l t e k S t a n d a r d M C U :
H T 4 8 X X X / H T 4 9 X X X
A N T
A N T
F u n c t i o n
C o n t r o l
H T 6 7 2 B
E n e r g y
D a t a
H o l t e k T r a n s p o n d e r S o l u t i o n
H o l t e k R e a d e r S o l u t i o n
R F o s c
&
R e c e i v e r
D a t a
D e c o d e
&
S y s t e m
C o n t r o l
H o l t e k E m b e d d e d M C U :
H T G 2 1 X X / H T 8 6 X X X
A N T
A N T
F u n c t i o n
C o n t r o l
D a t a , V o i c e
o r L C D
D i s p l a y
P r o c e s s i n g
PDF 
ZIP