Interfacing op amps to high-speed DACs Part 1 Current-sinking DACs[复制链接]
Introduction Digital-to-analog converters (DACs) come in many bit resolutions and sampling speeds. Outputs from lower-speed DACs are often single-ended and have either a voltage or a current output. Most highspeed DACs are designed with complementary outputs that either source or sink current. This article, Part 1 of a three-part series, discusses the interface between a current-sinking DAC and an op amp. Part 2, which will appear in a future issue of the Analog Applications Journal, will discuss the interface between a current-sourcing DAC and an op amp. Part 3, also in a future issue of the Analog Applications Journal, will provide a simplified approach to the interface analogy presented in Part 2. High-speed DACs are used in endequipment applications like communications, test equipment, medical applications, industrial applications, and many more where signal generation is required. Each of these applications has its own specific requirements for signal characteristics and performance. This article focuses on end equipment that requires DC coupling, like signal generators with frequency bandwidths of up to 100 MHz and a single-ended output. In these cases, high-speed op amps can provide a good solution for converting the complementary-current output from a highspeed DAC to a voltage that can drive the signal output