H4001

The H4001 is a CMOS integrated circuit for use in transponders. The circuit is powered by an external coil placed in a magnetic field, and gets its clock from the same field via one of the coil terminals. The other coil terminal of H4001 is affected by the modulator, turning on and off the modulation current in order to send back the 64 bits of information contained in a factory pre-programmed memory array.

The programming of the H4001 chip is performed by laser fusing of polysilicon links in order to store a unique code on each chip. The serial output data string contains a 9 bits header,40 bits of data, 14 parity bits, and 1 stop bit. Due to the low power consumption of the logic core,no supply buffer capacitor is required. Only an external coil is required to obtain the chip function. A parallel capacitor adjusted with the coil to obtain resonnance,will increase the read distance.