Analog Devices Inc. AD667JPZ

Summary of the Analog Devices AD667JPZ 12-Bit Voltage Output DAC

The Analog Devices AD667JPZ is a precision voltage-output digital-to-analog converter (DAC), delivering 12-bit resolution and high speed current steering capabilities. Designed to meet the demands of microprocessor-compatible systems, the AD667JPZ integrates a buffered voltage output, a buried Zener reference, and double-buffered latches—all on a single chip. Available in a space-saving 28-PLCC package (11.51 x 11.51 mm), the AD667JPZ provides versatile options for both surface mount and through-hole configurations, catering to a wide range of professional engineering and procurement requirements.

Main Technical Characteristics of the AD667JPZ

The AD667JPZ stands out due to its functional completeness and robust design. It features guaranteed monotonicity and linearity across its full operating temperature range. The internal buried Zener reference is laser trimmed for a tight ±1% maximum error, producing stable voltage outputs even under variable environmental conditions. The double-buffered latch structure allows seamless interfacing with 4-, 8-, 12-, or 16-bit data buses, improving noise immunity and reducing spurious output changes during data transfer. All logic inputs are TTL and 5V CMOS-compatible, making the device ideal for modern microprocessor-based systems. The AD667JPZ achieves a maximum settling time of 3 μs to 0.01% full-scale accuracy, supporting applications where speed and precision are critical. Its output amplifier, scaling resistor network, and optimized matching of gain and offset resistors ensure minimal gain and bipolar offset drift, consistently delivering accurate analog outputs.

Available Grades and Packaging Choices for the AD667JPZ

The AD667JPZ is offered in multiple grades to match varying performance and environmental requirements. The J and K variants, ideal for commercial applications, are rated for operation from 0°C to +70°C and are supplied in the 28-pin molded PLCC and DIP formats. Enhanced grades, including S, A, and B, extend the temperature range for industrial and military applications, with hermetically sealed ceramic options for –55°C to +125°C operation. Linearity and monotonicity are guaranteed, with the highest accuracy grades (K, B) specified to a maximum of ±1/4 LSB error at +25°C and ±1/2 LSB over their full temperature range. Designers can select the optimal grade based on required accuracy, environmental exposure, and preferred package.

AD667JPZ Electrical and Timing Details

The AD667JPZ operates with ±12V or ±15V analog and digital supply voltages, supporting a voltage range from ±11.4V to ±16.5V. Power consumption is typically 300 mW. Digital inputs accept logic levels from +2.0V to +5.5V for "1" and 0V to +0.8V for "0", ensuring broad compatibility. The transfer characteristics address both linearity and drift, with full-scale gain error typically within ±0.1–0.2% and unipolar offset error within ±1–2 LSB, both adjustable through dedicated trim resistors. Settling times vary by load and feedback configuration: a full-scale transition achieves ±0.01% accuracy in 2–4 μs, with 1 μs required for an LSB change. Output ranges are configurable (±2.5V, ±5V, ±10V, or 0 to +5V/+10V), and the device can supply up to ±5 mA current, with 40 mA short circuit protection.

Designing Analog Circuits with the AD667JPZ

The AD667JPZ is designed for flexibility in applications requiring high fidelity and speed. Internal scaling resistors allow configuration for bipolar or unipolar output ranges, and external trimming is facilitated using dedicated potentiometers for zero and gain adjustment. Engineering scenarios include precision instrumentation, industrial control, and process automation, where outputs must be calibrated for different ranges (e.g., ±10V versus 0–10V) depending on field needs. The AD667JPZ's analog grounds and output amplifier are isolated for optimal noise performance and can be directly connected to system analog reference points. The power ground is separately accessible, offering strategic flexibility for minimizing interference in complex systems.

Reference Selection and Application in the AD667JPZ

A key feature of the AD667JPZ is its internally buffered buried Zener reference, laser trimmed for accuracy and low temperature drift. This reference is optimized for DAC requirements and supports both internal and external configurations. Typically specified and tested with the internal reference, the AD667JPZ allows external references between +8V and +11V when application-specific scaling is required (such as 8.192V or 10.24V systems). The onboard reference output drives up to 0.1 mA externally; for higher loads, additional buffering is recommended. Engineering adjustments for full-scale and bipolar offset are easily accomplished using the onboard trim range; however, the use of external feedback resistors is not advised due to potential mismatches and increased drift.

Digital Connection and Bus Support for the AD667JPZ

Microprocessor compatibility is central to the AD667JPZ's design. Its double-buffered input latch avoids spurious outputs and supports direct interfacing with standard 4-, 8-, 12-, or 16-bit buses. Engineers can implement left- or right-justified 8-bit data formats, facilitating integration with legacy microprocessor platforms as well as modern systems. The AD667JPZ features level-triggered latches controlled by four address lines (A0–A3) and a chip select (CS) input. Timing requirements are minimal, with the device responding reliably to strobe pulses as short as 100 ns. The parallel bus supports high fanout, and input threshold voltages are fixed irrespective of supply fluctuations, ensuring robust operation in complex digital environments.

Design Considerations Grounding and Settling Time with AD667JPZ

For optimal analog performance, the AD667JPZ brings out analog and power ground pins separately. System designers should tie these together at a single point, preferably at the device power ground, to avoid ground loops and minimize noise. Decoupling capacitors must be placed from each power supply pin to the analog ground, and all loads should reference the analog ground. Settling time can be optimized further by adding a small feedback capacitor (e.g., 20 pF) across the internal feedback resistor, reducing large-signal settling time from 2.4 μs to 1.6 μs. These considerations are critical in high-speed data acquisition and control systems, where precision and responsiveness are paramount.

Environmental Standards and Reliability Information for AD667JPZ

The AD667JPZ is RoHS3 compliant and unaffected by current REACH regulations, allowing deployment in modern, environmentally-sensitive applications. The model is specified with a Moisture Sensitivity Level (MSL) of 3 (168 hours), and is available in military grades compliant with MIL-STD-883 for mission-critical and defense projects. All maximum ratings, including power supply and input voltages, are documented for safety and reliability, supporting risk assessments in procurement and lifecycle planning.

Alternative or Replacement Devices for the AD667JPZ

For those seeking alternate solutions, equivalent or replacement models should match the AD667JPZ’s core specifications—12-bit resolution, voltage output, double-buffered latches, microprocessor compatibility, and similar environmental and package options. Within Analog Devices' portfolio, models such as the AD668 and industry-standard DACs with comparable speed, accuracy, and reference performance may be considered. Procurement professionals and engineers should verify interface compatibility, settling time, and output range before substitution to ensure seamless integration within their system architecture.

Conclusion

The Analog Devices AD667JPZ is an advanced 12-bit voltage-output DAC offering precision, speed, and versatility for a wide range of engineering applications. With robust microprocessor interface logic, flexible analog circuit arrangements, specialized reference options, and comprehensive environmental compliance, the AD667JPZ stands as an ideal choice for engineers and procurement specialists aiming to achieve reliable and accurate digital-to-analog conversion in demanding projects. Evaluating its grades, package formats, and integration capabilities allows stakeholders to maximize the potential of this DAC, meeting both technical and project requirements with confidence.