Analog Devices Inc. AD7862ARS-3

Overview

AD7862ARS-3 from Analog Devices is a dual 12-bit simultaneous-sampling analog-to-digital converter with ±2.5 V input range, 250 kSPS throughput, and internal +2.5 V reference. It integrates two track-and-hold amplifiers, high-speed parallel interface, and operates from a single +5 V supply. Used in AC motor control and data acquisition systems requiring phase-coherent dual-channel sampling.

For engineers reviewing the AD7862ARS-3 datasheet, AD7862ARS-3 pinout, AD7862ARS-3 application, or AD7862ARS-3 equivalent, key selection considerations include simultaneous sampling capability, ±2.5 V bipolar input range, 3.6 µs conversion time, aperture delay matching of 200 ps, and SSOP-28 package compatibility with industrial temperature range (–40°C to +85°C).

Technical Context

The AD7862ARS-3 implements two independent successive-approximation ADCs sharing a common internal +2.5 V reference and synchronized by a single CONVST signal, enabling true simultaneous sampling across VA1/VA2 and VB1/VB2 channels. Its LC2MOS process ensures low power (60 mW typ) and robust overvoltage tolerance (±7 V on analog inputs).

Conversion control uses a dedicated BUSY output and standard CS/RD handshake with A0 multiplexer select for channel sequencing. The device supports twos-complement output coding and features matched aperture delay (20 ns typ) and jitter (100 ps typ), preserving inter-channel phase integrity for dynamic signal analysis.

Key Specifications

Pinout & Package

AD7862ARS-3 is housed in a 28-pin Shrink Small Outline Package (SSOP, RS-28) with 0.65 mm lead pitch, optimized for high-density industrial PCBs. Thermal resistance θ_JA = 110°C/W supports operation up to +85°C ambient without forced cooling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7862AR-3, AD7862ARS-3 offers identical performance in a smaller SSOP package for space-constrained designs; versus AD7863ARS-3, it trades 2-bit resolution for lower cost and simpler 12-bit data handling while maintaining identical timing, interface, and thermal behavior.

Availability

AD7862ARS-3 is available at Aetrix Electronics and suitable for AC motor control, uninterruptible power supplies, and data acquisition systems requiring stable component supply, long-term industrial lifecycle support, and RoHS-compliant packaging.

Supply support for AD7862ARS-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 simultaneous-sampling dual ADCs for industrial automation, energy systems, and test equipment where phase coherence and deterministic timing are critical to closed-loop control accuracy.

FAQ

What is the analog input voltage range supported by the AD7862ARS-3?

The AD7862ARS-3 supports a bipolar ±2.5 V analog input range, optimized for signal processing applications. This range allows direct interfacing with op-amp-based sensor conditioning circuits without external level-shifting. Overvoltage protection extends to ±7 V on all analog inputs, preventing damage during transient events. The internal scaling network ensures 12-bit resolution with 1.22 mV per LSB step size across the full range.

How does the AD7862ARS-3 achieve simultaneous sampling across two channels?

The AD7862ARS-3 achieves true simultaneous sampling using two independent track-and-hold amplifiers triggered by a single CONVST falling edge. Both amplifiers enter hold mode at the same instant, freezing their respective input signals (VA1/VA2 and VB1/VB2) before conversion begins. Aperture delay matching of 200 ps ensures phase coherence between channels, making AD7862ARS-3 suitable for vector measurements in motor control and power quality analysis.

Does the AD7862ARS-3 require an external reference voltage?

No, the AD7862ARS-3 includes an internal +2.5 V reference with ±10 mV accuracy at +25°C and 25 ppm/°C temperature coefficient. A 0.1 µF ceramic capacitor from VREF to AGND is sufficient for stable operation. However, the VREF pin also accepts external references (e.g., AD780 or REF43) for tighter tolerance or system-level reference synchronization - the internal reference is automatically overridden when an external source is applied.

What package type and thermal characteristics does the AD7862ARS-3 use?

The AD7862ARS-3 is packaged in a 28-pin Shrink Small Outline Package (RS-28) with 0.65 mm lead pitch and 110°C/W junction-to-ambient thermal resistance. This SSOP variant enables higher PCB density than SOIC alternatives while maintaining compatibility with standard reflow profiles. The device operates across –40°C to +85°C and dissipates 60 mW typical power, allowing reliable operation in enclosed industrial enclosures without active cooling.

Can the AD7862ARS-3 interface directly with common microcontrollers?

Yes, the AD7862ARS-3 features a standard 12-bit parallel interface with TTL-compatible DB11–DB0 outputs, active-low CS and RD controls, and BUSY status signaling - fully compatible with 8051, ARM Cortex-M, and FPGA-based controllers. Its 3.6 µs conversion time and 40 ns data access window allow zero-wait-state reads at 250 kSPS. No level-shifting or glue logic is needed when interfaced with +5 V microcontrollers.