Electrical Characteristics

Symbol

Parameter

Test Conditions

Min.

Typ.

Max.

Unit

Conditions

Operating Voltage

¾

234

V

Operating Current

2V

¾¾

15

¾mA

3V

Voltage limiter not started

¾

600

¾mA

Modulation Resistance

5V

¾¾

320

¾W

LC Input Limiter Voltage

¾¾

¾

6.5

¾

V

Output Data Baud Rate

3V

2.5

5

7.5

Kbps

Timing & Code Package

HT672A

Rev. 1.10

3

May 17, 2007

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 the internal RC-oscillator, the tran-

sponder is actuated to transmit its internal data serially

by means of damping the LC tank.

The reader receives the transponder

¢s data by means of

detecting the energy variation on its own antenna, and

recognize the information with a microcontroller.

The HT672A 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 96 bits of OTP memory space is provided, from

which 64 bits wide are customer programmable, which

can be programmed using the specified programmer

supplied by Holtek. The pre-programmed ICs are also

available upon customer

¢s request.

H T 6 7 2 A

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

T r a n s p o n d e r

H T 6 7 2 A

D a t a O u t

A g e n t I D

( H o l t e k d e f i n e d )

C u s t o m e r I D

( A g e n t d e f i n e d )

( 8 b i t s )

( 8 b i t s )

( 8 b i t s )

( 5 6 b i t s )

( 1 6 b i t s )

C a t e g o r y I D

( C u s t o m e r d e f i n e d )

P r o d u c t I D

( C u s t o m e r d e f i n e d )

C R C

* C u s t o m e r P r o g r a m m a b l e

C o d e A r e a ( 6 4 b i t s M a x . )

P r o d u c t D a t a ( 6 4 b i t s )

T o t a l E P R O M s p a c e ( 9 6 b i t s )