AD7840ARSZ-REEL

Overview

The AD7840ARSZ-REEL is a complete 14-bit voltage output digital-to-analog converter (DAC) fabricated in LC2MOS technology. It integrates a 3 V buried Zener reference, DAC output amplifier, and high-speed control logic. The device supports both parallel and serial interfaces, enabling direct connection to DSPs like the ADSP-2100. Key electrical parameters include a typical signal-to-noise ratio of 80 dB, a settling time of 4 µs max, and an analog output range of ±3 V. It operates from dual ±5 V supplies with typical power dissipation of 70 mW.

Feature Summary

• Complete 14-bit voltage output DAC with on-chip 3 V reference and buffer amplifier
• Dual interface capability: 14-bit parallel mode or 6 MHz serial mode
• High dynamic performance: 80 dB SNR and -80 dB THD typical
• Fast settling time of 4 µs maximum for full-scale transitions

Applications

• Direct interfacing with high-speed DSP processors such as ADSP-2100 and TMS320 series
• Speech synthesis systems requiring precise waveform generation
• Servo control loops demanding monotonicity and fast update rates
• High-speed modem applications utilizing AC signal specifications

Procurement Notes

Verify the ordering suffix 'ARSZ' corresponds to the industrial temperature range (-25°C to +85°C), SSOP-24 package, and RoHS compliance. Confirm that the '-REEL' designation indicates tape-and-reel packaging rather than tube packaging. Ensure the specific grade meets the required Signal-to-Noise Ratio (78 dB min) and Integral Nonlinearity (±2 LSB max) specifications for the application.

Selection Notes

Select this component when a complete 14-bit solution with integrated reference and output buffer is required. Choose the ARSZ variant for industrial temperature operation compared to the commercial JN version. Consider the serial interface option if pin count reduction is necessary, noting that CS must be tied to VSS for serial mode. Verify supply voltage compatibility with dual ±5 V rails and ensure load conditions do not exceed the 20 mA short-circuit current limit.

Part Context

The AD7840 belongs to Analog Devices' family of complete DACs designed for DSP-based systems. It utilizes LC2MOS technology, combining precision bipolar circuits with low-power CMOS logic. This architecture allows for high speed and low power consumption while maintaining 14-bit accuracy. The device is part of a broader lineup including variants with different temperature ranges and package styles, such as DIP and PLCC.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.