AD7874AR-REEL7

ADCs/DACs - Special Purpose Overview

The AD7874AR-REEL7 is a four-channel, 12-bit simultaneous sampling data acquisition system manufactured by Analog Devices Inc. It integrates high-speed track/hold amplifiers, an ADC, and a reference buffer in a 28-pin SOIC package. The device operates on dual ±5 V supplies with a nominal 3 V internal reference. Key electrical parameters include a 29 kHz sample rate for all channels, 2 μs acquisition time, and 32.5 μs maximum conversion time. DC accuracy specifications feature ±1 LSB relative accuracy and ±5 LSB full-scale error.

ADCs/DACs - Special Purpose Feature Summary

• Four independent on-chip track/hold amplifiers enable true simultaneous sampling of input channels.
• Tight aperture delay matching ensures less than 4 ns deviation between channels to preserve phase information.
• Integrated 3 V buried Zener reference with buffered output capability.
• Fast parallel digital interface compatible with 16-bit microprocessors and DSPs.

ADCs/DACs - Special Purpose Applications

• Phased-array sonar systems
• AC motor controllers
• Adaptive filters
• Digital signal processing

ADCs/DACs - Special Purpose Procurement Notes

Verify the REEL7 suffix indicates tape-and-reel packaging rather than tube packaging when sourcing this specific variant. Confirm the 'A' version designation corresponds to the standard -40°C to +85°C operating range and ±1 LSB accuracy class. Ensure supply voltages are strictly maintained within ±5% of nominal ±5 V levels.

ADCs/DACs - Special Purpose Selection Notes

Select the AD7874AR-REEL7 when simultaneous multi-channel sampling is required to maintain phase coherence. The part requires dual ±5 V power rails and supports external or internal 3 V references. Consider the S-version if extended temperature operation down to -55°C is necessary, as the A-version is limited to -40°C minimum.

ADCs/DACs - Special Purpose Part Context

This component belongs to the AD7874 family of specialized data acquisition ICs. The 'AR' suffix denotes the SOIC package option and the commercial temperature grade. The '-REEL7' suffix specifies the reel packaging format for automated surface-mount assembly processes.

ADCs/DACs - Special Purpose Replacement Considerations

The AD7874BRZ offers improved integral nonlinearity (±0.5 LSB) compared to the AR version's ±1 LSB specification while maintaining identical pinouts and functionality.

ADCs/DACs - Special Purpose FAQ

How does the AD7874 handle channel addressing during data readout?

The device uses an implicit addressing scheme. Four successive reads to the same memory location automatically access Data Registers 1 through 4 in sequence, corresponding to Channels 1 through 4.

What is the maximum recommended capacitance on the REF OUT pin?

The maximum recommended capacitance on the REF OUT pin for normal operation is 50 pF.

Can multiple AD7874 devices be synchronized for multi-channel applications?

Yes, the tight aperture delay matching allows multiple devices to sample simultaneously without significant phase errors. Additionally, one device's REF OUT can drive the REF IN of other devices to ensure full-scale tracking.