The EM4100/EM4102 (previously named H4100/H4102) is a CMOS integrated circuit for use in electronic Read Only RF Transponders. The circuit is powered by an external coil placed in an electromagnetic field, and gets its master clock from the same field via one of the coil terminals. By turning on and off the modulation current, the chip will send back the 64 bits of information contained in a factor y pre-programmed memory array.
The programming of the chip is performed by laser fusing of polysilicon links in order to store a unique code on each chip.
The EM4100/EM4102 has several metal options which are used to define the code type and data rate. Data rates of 64, 32 and 16 periods of carrier frequency per data bit are available. Data can be coded as Manchester, Biphase or PSK.
Due to low power consumption of the logic core, no supply buffer capacitor is required. Only an external coil is needed to obtain the chip function. A parallel resonance capacitor of 74 pF is also integrated.

For further information about EM Contactless Chip, please visit EM Microelectroic.

The Difference between EM H4100 and EM H4102:

There is no difference of EM H 4100 and EM H4102 in term of electrical function.
The main difference is that EM4102 chip has gold bumps on the die, so the coil (antenna) can be directly connected to the die.
EM Cards
EM H4100 die is first packed in a lead frame IC module then connected to the coil. The thickness of lead frame IC module is about 0.4mm.
EM Cards
The coil is directly connected (direct bonding) to EM H4102 die. The thickness of die is about 0.2mm only and in order to do direct bonding task we have to use thinner coil.
Since EM H4102 ISO card does not need lead frame IC module and use thinner coil so the card surface will be much flatter than EM H4100 ISO card.
The flatter card surface means better printing quality especially when using dye-sublimation printer.