AD7840JP

Overview

The AD7840JP 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 minimum signal-to-noise ratio of 78 dB and total harmonic distortion of -80 dB at +25°C. The part is housed in a 28-lead plastic leaded chip carrier package.

Feature Summary

• Complete 14-bit voltage output DAC with integrated 3 V reference and output buffer
• Dual interface capability: 14-bit parallel mode with 21 ns setup time and serial mode up to 6 MHz clock rate
• High dynamic performance: 78 dB SNR and -80 dB THD at 1 kHz output frequency
• Low power consumption: typically 70 mW with ±5 V supplies

Applications

• Direct interfacing with high-speed DSP processors such as ADSP-2100, TMS32010, and TMS32020
• Speech synthesis systems requiring precise waveform generation
• Servo control applications needing fast settling times
• High-speed modem signal generation

Procurement Notes

Verify the specific suffix JP indicates the 28-lead PLCC package and commercial temperature range (0°C to +70°C). Confirm that the ordering suffix does not alter the electrical function unless explicitly stated in the manufacturer's documentation. Check for availability of military-grade variants if extended temperature ranges are required.

Selection Notes

Select the AD7840JP when a 14-bit resolution with ±3 V output swing is required. Ensure the system can provide ±5 V supplies. Choose this model over the JN variant if surface-mount PLCC packaging is preferred. Verify that the 78 dB SNR meets the application's noise requirements; consider the KP variant for higher SNR if needed.

Part Context

The AD7840 belongs to Analog Devices' LC2MOS family of complete DACs. It is distinct from ADC models like the AD7870 or other DACs like the AD7535. The JP suffix specifically denotes the plastic leaded chip carrier package version within the AD7840 product line, differing from the DIP (JN) or Cerdip (AQ/SQ) packages.

Replacement Considerations

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