AD7840ARSZ

Overview

The AD7840ARSZ is a complete 14-bit voltage output digital-to-analog converter (DAC) fabricated in linear compatible CMOS (LC2MOS). It integrates a 14-bit DAC, a 3 V buried Zener reference, an output amplifier, and high-speed control logic. The device supports both parallel and serial interfaces, enabling direct connection to DSPs like the ADSP-2100. It operates from ±5 V supplies with typical power dissipation of 70 mW. The analog output provides a bipolar range of ±3 V. Key dynamic specifications include a signal-to-noise ratio of 76 dB minimum and settling time within ±1/2 LSB in 4 μs maximum.

Feature Summary

• Complete 14-bit voltage output DAC with integrated 3 V reference and output buffer
• Dual interface capability: Parallel mode with 21 ns setup time; Serial mode up to 6 MHz clock
• Extended temperature range (-55°C to +125°C) for industrial applications
• Low power consumption: Typically 70 mW at ±5 V supplies

Applications

• Direct interfacing with high-speed DSP processors such as ADSP-2100 and TMS320 series
• Speech synthesis and servo control systems requiring precise AC signal generation
• High-speed modem applications utilizing DAC dynamic performance specifications
• Industrial instrumentation requiring extended temperature operation stability

Procurement Notes

Verify the ordering suffix 'ARSZ' corresponds to the RS-24 package and -55°C to +125°C temperature range per the manufacturer's ordering guide. Confirm RoHS compliance status as datasheet revisions may vary. Ensure supply voltages are strictly maintained within ±5% of ±5 V to meet specified performance parameters. Check for ESD sensitivity precautions during handling.

Selection Notes

Select the AD7840ARSZ when extended temperature operation (-55°C to +125°C) is required, distinguishing it from commercial J/K or industrial A/B variants. Choose this model if the RS-24 surface-mount package is preferred over DIP or PLCC options. Verify that the 76 dB SNR specification meets system noise requirements, noting that higher grades like the B variant offer 80 dB SNR.

Part Context

The AD7840 belongs to Analog Devices' family of complete 14-bit DACs. Variants include AD7840JN (Commercial, DIP), AD7840KP (Commercial, PLCC), and AD7840BQ (Industrial, Cerdip). The ARSZ designation specifically denotes the Industrial grade with extended temperature limits and SSOP/RS-24 packaging. All variants share identical electrical core functionality but differ in thermal range and physical footprint.

Replacement Considerations

Public confirmed substitutes include AD7840AR (Industrial, Q-24 package) and AD7840BRZ (Industrial, SSOP package). Verify pin compatibility and temperature range alignment. Note that ordering suffixes indicate package type and temperature grade; ensure the replacement matches the RS-24 form factor if space constraints exist.