1.0 Introduction

　　The DAC121C08XEB Design Kit （consisting of the DAC Evaluation Board and this User‘s Guide） is designed to ease evaluation and design-in of National Semiconductor’s DAC121C081/DAC121C085 family of Digital-toAnalog Converters （DACs）。 The Micro-Power DACs feature Rail-to-Rail Output and an I2 C- Compatible interface. This User’s Guide supports all three resolutions of the DAC family. The evaluation board comes with the full-featured MSOP-8 version of the DAC. For the 12-bit resolution， the DAC121C085 is used. For the 10- bit resolution， the DAC101C085 is used. For the 8-bit resolution， the DAC081C085 is used. All the devices in the family （DAC121C085， DAC101C085， and DAC081C085） will be referred to as the DAC121C085 in this document.

　　The evaluation board can be used in either of two modes. In the Stand-Alone mode， suitable test equipment， such as a pattern generator and signal analyzer， can be used with the board to evaluate the DAC121C085 performance.