**AD7248AAPZ: A Comprehensive Technical Overview of the 12-Bit CMOS DAC**
The **AD7248AAPZ** is a monolithic, 12-bit digital-to-analog converter (DAC) fabricated on a **high-performance CMOS process**. This device integrates a precision voltage reference, a DAC, and output amplifier circuitry into a single package, making it a complete, self-contained solution for a wide range of digital-to-analog conversion applications. Its design emphasizes accuracy, speed, and versatility.
At its core, the AD7248AAPZ utilizes a **12-bit current-steering DAC architecture**, which is latched and followed by a precision, high-speed amplifier. This configuration ensures stable and accurate analog output. The on-chip **buried Zener voltage reference** provides a stable 2.5V foundation, which is a critical factor for the overall accuracy and low drift performance of the converter. This internal reference can be overridden by an external reference source if a different output range or higher precision is required, offering significant design flexibility.
The device operates with a standard **microprocessor-compatible interface**, featuring double-buffered input logic. This includes a 12-bit data input port and separate control lines for the input latch and DAC latch. This double-buffering allows the user to simultaneously update the outputs of multiple AD7248s, which is essential for multi-channel systems requiring synchronous output changes. The interface supports data loading in 12-bit or two 8-bit right-justified bytes, ensuring easy interfacing with most popular microprocessors and digital systems.
The AD7248AAPZ is designed to provide both voltage output ranges: a **bipolar output range of ±3V** and a **unipolar output range of 0V to +5V**. The desired range is user-selectable by simply connecting a single pin to either the internal reference output or analog ground, respectively. The output amplifier is capable of driving a 2kΩ load in parallel with a 500pF capacitance, making it suitable for driving various subsequent stages in signal chain applications.
Key performance specifications include a **typical settling time of 10μs to ±0.5 LSB** for a full-scale step, which defines its speed and capability for dynamic applications. The device guarantees monotonicity over its full operating temperature range, a fundamental requirement for any precision DAC. It is available in a 24-lead PDIP or SOIC package (the "PZ" suffix denotes the SOIC package), catering to both through-hole and surface-mount assembly processes.
Typical applications span across industrial control systems, automated test equipment (ATE), digital offset and gain adjustment, and programmable voltage sources. Its combination of integrated features, precision, and ease of use makes it a robust choice for designers.
**ICGOOODFIND**: The AD7248AAPZ stands out as a highly integrated, precise, and flexible 12-bit DAC solution. Its combination of an internal reference, fast settling time, and microprocessor-compatible interface makes it an excellent choice for a vast array of digital-to-analog conversion tasks, simplifying design and enhancing system reliability.
**Keywords**: 12-Bit DAC, CMOS Process, Voltage Reference, Monotonic, Settling Time.
