HT672B

Supply Voltage (VDD) ............................................5.5V
Storage Temperature ...........................-50 to 125
Supply Voltage (VPA) ..........................................12.5V
Operating Temperature ..............................0 to 70
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 reliability.

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 reserved for customer) in the chip, with a 8-bits checksum code. 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 detection range. HT672B is advisable to use larger antenna to attain a 15cm detection range. Implementing Holteks advanced OTP and low power technology, 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 program the device using the specified programmer supplied by Holtek. The pre-programmed Ics are also available upon customers request.