AD7840KPZ

Overview

The AD7840KPZ is a complete 14-bit voltage output digital-to-analog converter (DAC) fabricated in LC2MOS technology. 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 high-speed DSP processors like the ADSP-2100 and TMS320 series. 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 80 dB minimum and total harmonic distortion of -80 dB 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 and Serial mode with 6 MHz clock rate
• High dynamic performance: 80 dB SNR and -80 dB THD typical at +25°C
• LC2MOS process combining precision bipolar circuits with low-power CMOS logic

Applications

• Direct interfacing with high-speed DSP processors such as ADSP-2100 and TMS32010/20
• Speech synthesis systems requiring precise ac signal generation
• Servo control applications needing fast settling times
• High-speed modem data conversion

Procurement Notes

Verify the specific suffix 'KPZ' against the manufacturer's current ordering guide, as standard documentation lists 'KP' for the PLCC package. Confirm RoHS compliance status, as earlier revisions or variants may differ. Check lead time and availability directly with Analog Devices or authorized distributors, as this component may be subject to lifecycle changes or limited stock conditions.

Selection Notes

Select the AD7840KPZ when a 14-bit resolution with ±3 V output range is required. Ensure the system can provide ±5 V supplies. Choose the PLCC package if surface mount assembly is preferred over DIP. Verify that the interface logic matches the host processor's timing requirements, specifically the 45 ns WR pulse width for parallel mode or 6 MHz SCLK for serial mode.

Part Context

The AD7840 belongs to the AD7840 family of complete DACs. Variants include JN, KN, JP, KP (commercial temperature), AQ, ARS, BQ (industrial), and SQ (extended). The 'K' grade indicates a minimum SNR of 80 dB and integral nonlinearity of ±1 LSB. The 'P' denotes the PLCC-28 package. The 'Z' suffix typically indicates RoHS compliance in Analog Devices nomenclature.

Replacement Considerations

For pin-compatible replacements, consider the AD7840KN (DIP) or AD7840KP (PLCC) for identical electrical performance. For upgraded alternatives, evaluate the AD7535 or AD7834 families, though interface and pinout differences may require schematic modifications.