The AD7991/AD7995/AD7999 are 12-/10-/8-bit, low power, successive approximation ADCs with an I2C-compatible interface. Each part operates from a single 2.7 V to 5.5 V power supply and features a 1 s conversion time. The track-and-hold amplifier allows each part to handle input frequencies of up to 14 MHz, and a multiplexer allows taking samples from four channels.