Analog Devices Inc. AD7829BRU-1

Overview

AD7829BRU-1 from Analog Devices is a high-speed, 8-channel, 8-bit parallel-output analog-to-digital converter (ADC) with 420 ns conversion time, 2 MSPS throughput, on-chip 2.5 V reference, and track-and-hold amplifier. It operates from single 3 V ±10% or 5 V ±10% supply and supports data acquisition in DSP front ends and mobile communication subsampling systems.

For engineers reviewing the AD7829BRU-1 datasheet, AD7829BRU-1 pinout, AD7829BRU-1 application, or AD7829BRU-1 equivalent, key selection considerations include its 8-channel single-ended input architecture, automatic power-down via CONVST, EOC-driven stand-alone operation, and VMID-adjustable input span for system offset compensation.

Technical Context

The AD7829BRU-1 implements a half-flash ADC architecture with two-stage conversion: a 4-bit coarse flash followed by a 4-bit fine flash to achieve full 8-bit resolution. Its track-and-hold enters hold mode on the falling edge of CONVST and returns to track mode 120 ns later, enabling overlapping acquisition and conversion cycles.

Channel selection is performed externally via A2–A0 address inputs synchronized with RD, eliminating internal register writes. The parallel interface uses CS/RD/EOC/CONVST control signals and 8-bit bidirectional data bus (DB0–DB7), supporting direct microprocessor and DSP interfacing without glue logic beyond address decoding.

Key Specifications

Pinout & Package

AD7829BRU-1 is housed in a 28-lead wide-body SOIC (SOIC_W) package with standard 0.3-inch body width and 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit, multi-channel, parallel-output ADC applications.

Compared with AD7828BRU-1 and MAX1186EEE+, the AD7829BRU-1 uniquely combines integrated 2.5 V reference, parallel interface, and VMID-adjustable input span-making it optimal for cost-sensitive, medium-speed, multi-channel acquisition where layout simplicity and analog flexibility are prioritized over minimal footprint or ultra-low power.

Availability

AD7829BRU-1 is available at Aetrix Electronics and suitable for high-speed data acquisition systems, DSP front ends, and mobile communication subsampling applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for AD7829BRU-1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA, with design and manufacturing operations worldwide.

The AD7829 family was engineered for high-throughput, low-latency analog digitization in real-time embedded systems-emphasizing parallel interface simplicity, flexible supply operation, and analog input adaptability for industrial and communications equipment.

FAQ

What is the maximum sampling rate supported by the AD7829BRU-1?

The AD7829BRU-1 supports a maximum throughput of 2 MSPS, enabled by its 420 ns conversion time. This rate is achievable across the full −40°C to +85°C industrial temperature range when operated within specified supply (3 V ±10% or 5 V ±10%) and timing conditions. The EOC pulse width and RD timing constraints must be met to sustain this rate in continuous acquisition mode.

Does the AD7829BRU-1 require an external reference voltage?

No, the AD7829BRU-1 includes an on-chip 2.5 V reference with ±50 mV accuracy and 50 ppm/°C temperature coefficient. The VREF IN/OUT pin can be left unconnected for internal reference use or decoupled to AGND with a 0.1 µF capacitor. An external 2.5 V reference may be applied if higher initial accuracy or lower drift is required, but the AD7829BRU-1 does not support adjustable reference voltages.

How does the VMID pin affect analog input range in the AD7829BRU-1?

The VMID pin sets the center point of the AD7829BRU-1's analog input span. With VMID unconnected, the default span is 0 V to 2.0 V (3 V supply) or 0 V to 2.5 V (5 V supply). When an external voltage is applied to VMID, the span becomes VMID ±1.0 V (3 V) or VMID ±1.25 V (5 V), enabling bipolar signal digitization and system offset cancellation without external op-amps.

Can the AD7829BRU-1 operate from a 3.3 V supply?

Yes-the AD7829BRU-1 is fully specified for 3 V ±10%, meaning it operates reliably from 2.7 V to 3.3 V. At 3.3 V, the input span remains 0 V to 2.0 V, LSB size equals 0.8 × VREF / 256, and logic thresholds adjust accordingly (e.g., VINH ≥ 2.0 V, VINL ≤ 0.4 V). Power dissipation increases slightly versus 3.0 V nominal but stays within 36 mW max.

What is the purpose of the automatic power-down feature in the AD7829BRU-1?

The AD7829BRU-1 automatically enters power-down mode at the end of conversion if the CONVST pin is sampled low when EOC goes high. This reduces supply current from 12 mA (normal) to 5 μA (power-down), cutting dynamic power by >99% between conversions. It is especially valuable in burst-mode applications like mobile comms receivers, where duty-cycle-limited sampling maximizes battery life without software overhead.