Main chip: PCF8951Single power supplyOperating voltage range of 2.5V ~ 6VLow standby currentVia I2C-bus serial input / outputAddressing by 3 hardware address pinsPCF8591 sampling rate decided by I2C bus speed4 analog inputs programmable as single-ended or differential inputsAuto increment channel selectionPCF8591 analog voltage range from VSS to VDDPCF8591 built-track and hold circuit8-bit successive approximation A / D converterDAC gain realized by one analog outputPCB size: 3.6 x 2.3cm