There are four versions: the KTD2052A/C are defaulted disabled at initial power-up, while the KTD2052B/D execute an AutoBreathe™ pattern by default at initial power-up or when reset. The KTD2052A/B use 0x74 7-bit I2C slave address, while the KTD2052C/D use 0x75. BrightExtend™ optionally reduces dropout when the input voltage is too low for the forward voltage of the LEDs. Programmable CoolExtend™ prevents excessive heat when the input voltage, current settings, and ambient temperature are high. The Kinetic Technologies KTD2052 is packaged in a RoHS and Green compliant 2mm x 2mm UDFN package.