Analog Devices Inc. AD7862ARZ-3

Overview

AD7862ARZ-3 from Analog Devices is a dual 12-bit simultaneous-sampling analog-to-digital converter (ADC) with ±2.5 V input range, 250 kSPS throughput, 3.6 µs conversion time, and integrated +2.5 V reference. It preserves phase coherence between channel A (VA1/VA2) and channel B (VB1/VB2) for synchronized acquisition in motor control and power monitoring systems.

For engineers reviewing the AD7862ARZ-3 datasheet, AD7862ARZ-3 pinout, AD7862ARZ-3 application, or AD7862ARZ-3 equivalent, this page delivers verified specifications, validated pin functions, confirmed dual-channel timing behavior, real-world use cases in AC motor control and UPS systems, and two technically documented alternative parts with explicit functional and interface differences.

Technical Context

The AD7862ARZ-3 implements two independent successive-approximation ADCs with matched track-and-hold amplifiers, enabling true simultaneous sampling across four analog inputs (VA1/VA2/VB1/VB2) grouped into two channels. Its internal laser-trimmed clock oscillator eliminates external timing components.

It uses a high-speed parallel 12-bit TTL-compatible interface with CS/RD/CONVST control logic and A0 multiplexer select to sequence read access between VA1/VB1 and VA2/VB2 outputs. Aperture delay matching is 200 ps typ, supporting precise phase-critical signal capture.

Key Specifications

Pinout & Package

AD7862ARZ-3 is housed in a 28-lead SOIC (Small Outline Integrated Circuit) package with standard 0.3-inch body width and gull-wing leads. Pin 1 is located at the top-left corner adjacent to the index mark.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel simultaneous-sampling ADC applications.

Compared with AD7862ARZ-3, AD7863ARZ-3 offers higher resolution but sacrifices speed and increases power; ADS8325IPW reduces integration density and eliminates phase coherence-neither is pin-compatible, and both require PCB layout changes and firmware adaptation.

Availability

AD7862ARZ-3 is available at Aetrix Electronics and suitable for AC motor control, uninterruptible power supplies, and industrial data acquisition systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AD7862ARZ-3 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, founded in 1965 and headquartered in Wilmington, MA.

The AD7862 product line delivers dual-channel simultaneous-sampling ADCs for phase-sensitive measurement systems including motor drives, power quality analyzers, and communications infrastructure where timing coherence between analog channels is critical.

FAQ

What is the maximum analog input voltage the AD7862ARZ-3 can tolerate without damage?

The AD7862ARZ-3 features overvoltage protection rated to ±7 V on all analog inputs (VA1, VA2, VB1, VB2) relative to AGND. This allows safe operation during transient events such as inductive kickback or sensor disconnect, provided the absolute maximum ratings (e.g., VDD to AGND ≤ +7 V) are not exceeded. The ±2.5 V input range remains valid for accurate conversion; voltages beyond that range will saturate but not damage the device.

Does the AD7862ARZ-3 require an external reference, or does it include an internal one?

The AD7862ARZ-3 includes a fully integrated +2.5 V reference accessible via the VREF pin. When used internally, it delivers ±10 mV accuracy at +25°C and ±25 mV over –40°C to +85°C, with 25 ppm/°C temperature coefficient. A 0.1 µF ceramic capacitor from VREF to AGND is mandatory for stability. An external 2.5 V reference (e.g., AD780) may be connected to VREF to improve accuracy, but is not required for standard operation of the AD7862ARZ-3.

How does the AD7862ARZ-3 handle simultaneous sampling of two channels?

The AD7862ARZ-3 uses two physically matched track-and-hold amplifiers triggered by the same CONVST falling edge, achieving 200 ps typical aperture delay matching between channels. This ensures VA1/VA2 (Channel A) and VB1/VB2 (Channel B) are sampled at precisely the same instant, preserving phase relationships for FFT-based analysis or vector control algorithms. Conversion results are then made available sequentially via the parallel bus under A0 and RD control.

What is the function of the A0 pin on the AD7862ARZ-3, and how does it affect data reads?

The A0 pin on the AD7862ARZ-3 selects which pair of conversion results appears on the DB11–DB0 bus during a read cycle. With A0 low and CS/RD asserted, the first read returns VA1 (Channel A, Input 1) or VB1 (Channel B, Input 1); the second read returns VA2 or VB2. With A0 high, the order reverses: first read yields VA2/VB2, second yields VA1/VB1. This multiplexing enables compact firmware handling of dual-channel data without additional address decoding logic.

Can the AD7862ARZ-3 operate from a single +5 V supply, and what are its power consumption characteristics?

Yes, the AD7862ARZ-3 operates exclusively from a single +5 V supply (±5% tolerance). In normal operation, it draws 15 mA max (75 mW max), typically 60 mW. In auto power-down mode-activated automatically after conversion completion-it reduces supply current to 25 µA max (125 µW max), making it suitable for battery-powered portable instrumentation. No negative or auxiliary supplies are required for the AD7862ARZ-3 to meet all specifications.