The PCA9691 is a single chip, single supply, low power, 8-bit CMOS data acquisition device with four analog inputs, one analog output and a serial I2C-bus interface. Three address pins (A0, A1 and A2) are used for programming the hardware address, allowing the use of up to 64 PCA9691 devices connected to the I2C-bus without additional hardware. Address, control and data to and from the PCA9691 are transferred via the serial two-line bidirectional I2C-bus.