The AK2574 is a 1chip LDD (Laser Diode Driver) and an APC (Auto Power Control) for burst mode application such as ATM-PON. It contains not only 156M LDD for modulatin current but also BIAS current switching, programmable BIAS and modulation currents, duty adjustment, I2CTM interface, an EEPROM for storing LD characteristics and user information. The AK2574 has an APC FF (Feed-forward) function that supplies a programmed current in response to the temperature. All program and operational functions can be set through the I2CTM compatible interface and stored in the on-chip EEPROM.