ICs can have different manufacturers (known as foundries). Applications There are numerous applications of mixed-signal integrated circuits, such as in mobile phones, modern radio and telecommunication systems, sensor systems with on-chip standardized digital interfaces (including I2C, UART, SPI, or CAN), voice-related signal processing, aerospace and space electronics, the Internet of things (IoT), unmanned aerial vehicles (UAVs), and automotive and other electrical vehicles. Mixed-signal circuits or systems are typically cost-effective solutions, such as for building modern consumer electronics and in industrial, medical, measurement, and space applications. Examples of mixed-signal integrated circuits include data converters using delta-sigma modulation, analog-to-digital converters and digital-to-analog converters using error detection and correction, and digital radio chips. Digitally controlled sound chips are also mixed-signal circuits. With the advent of cellular and network technology, this category now includes cellular telephone, software radio, and LAN and WAN router integrated circuits. Design and development Typically, mixed-signal chips perform some whole function or sub-function in a larger assembly, such as the radio subsystem of a cell phone, or the read data path and laser SLED control logic of a DVD player. Mixed-signal ICs often contain an entire system-on-a-chip. They may also contain on-chip memory blocks (like OTP), which complicates the manufacturing compared to analog ICs. A mixed-signal IC minimizes off-chip interconnects between digital and analog functionality in the system—typically reducing size and weight due to minimized packaging and a smaller module substrate—and therefore increases the reliability of the system. Because of the use of both digital signal processing and analog circuitry, mixed-signal ICs are usually designed for a very specific purpose. Their design requires a high level of expertise and careful use of computer aided design (CAD) tools. There also exists specific design tools (like mixed-signal simulators) or description languages (like VHDL-AMS). Automated testing of the finished chips can also be challenging. Teradyne, Keysight, and Advantest are the major suppliers of the test equipment for mixed-signal chips. There are several particular challenges of mixed-signal circuit manufacturing: CMOS technology is usually optimal for digital performance, while bipolar junction transistors are usually optimal for analog performance. However, until the last decade, it was difficult to combine these cost-effectively or to design both in a single technology without serious performance compromises. The advent of technologies like high performance CMOS, BiCMOS, CMOS SOI, and SiGe have removed many of these former compromises. Testing functional operation of mixed-signal ICs remains complex, expensive, and often is a