HT6740

13.56MHz RFID Transponder

Block Diagram

Rev. 1.20

1

May 17, 2007

Features

tion - not for volume production

Applications

General Description

The HT6740 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.

HT6740 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 17 bits one

time programmable memory OTP, with a 6-bit check

sum (up to 11 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, HT6740 offers a very cost effective solution

for RF contactless detection system.

A code area of 11 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.

The HT6740 has a built-in anti-collision function. Cus-

tomers can choose with anti-collision or with non

anti-collision function in the program software tool sup-

plied by Holtek.

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

R a n d o m

C o u n t e r

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