Analog Devices Inc. AD7865ASZ-1REEL

Overview

AD7865ASZ-1REEL from Analog Devices is a four-channel, simultaneous-sampling, 14-bit analog-to-digital converter (ADC) with 2.4 µs conversion time per channel, ±10 V/±5 V input ranges, and integrated track/hold amplifiers. It operates from a single 5 V supply, consumes 115 mW typical power, and delivers 77 dB SNR at 100 kHz input-used in industrial motor control and power metering systems requiring phase-coherent multichannel acquisition.

For engineers reviewing the AD7865ASZ-1REEL datasheet, AD7865ASZ-1REEL pinout, AD7865ASZ-1REEL application, or AD7865ASZ-1REEL equivalent, key selection criteria include simultaneous sampling capability, aperture delay matching ≤4 ns, bipolar input range support, parallel 14-bit interface timing, and PQFP-44 package compatibility for high-density industrial PCB layouts.

Technical Context

The AD7865ASZ-1REEL implements a successive approximation ADC architecture with four independent track/hold amplifiers, enabling true simultaneous sampling across all channels to preserve inter-channel phase relationships. Its internal 2.5 V reference, laser-trimmed oscillator, and hardware/software channel selection logic allow flexible sequencing without external clocking.

It supports two read modes-reading between conversions (using EOC strobes) or reading after full sequence completion (using BUSY)-and features overvoltage protection up to ±18 V on analog inputs. The device uses two's complement output coding and provides 0.35 µs track/hold acquisition time to maintain accuracy at 100 kSPS aggregate throughput.

Key Specifications

Pinout & Package

The AD7865ASZ-1REEL is housed in a 44-lead Plastic Quad Flatpack (PQFP) measuring 10 mm × 10 mm with 0.8 mm lead pitch. All AGND pins (12, 17, 23, 26) must be connected to system analog ground; DVDD and AVDD are tied externally; VDRIVE may be set to 3 V for interfacing with low-voltage processors.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7865ASZ-1REEL, AD7656ASTZ trades channel count and interface simplicity for resolution and serial flexibility, while ADS8588HIPM expands channel density at the expense of speed-making AD7865ASZ-1REEL optimal for cost-sensitive, phase-critical 4-channel industrial control where 14-bit fidelity and 2.4 µs latency are essential.

Availability

AD7865ASZ-1REEL is available at Aetrix Electronics and suitable for AC motor control, uninterruptible power supplies, and industrial power meters requiring stable component supply across extended product lifecycles.

Supply support for AD7865ASZ-1REEL 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 AD7865ASZ-1REEL belongs to Analog Devices' precision data acquisition portfolio, designed specifically for industrial automation systems demanding simultaneous multichannel sampling, robust noise immunity, and long-term calibration stability.

FAQ

What input voltage ranges does the AD7865ASZ-1REEL support?

The AD7865ASZ-1REEL supports ±10 V and ±5 V bipolar input ranges, as indicated by the "-1" suffix in its part number. It does not support unipolar (0 V to 5 V) or ±2.5 V ranges-those are assigned to AD7865ASZ-2 and AD7865ASZ-3 variants respectively. Input overvoltage tolerance reaches ±18 V for the ±10 V range configuration, protecting against transient surges without affecting adjacent channels.

How does the AD7865ASZ-1REEL achieve simultaneous sampling across four channels?

The AD7865ASZ-1REEL achieves true simultaneous sampling using four independent on-chip track/hold amplifiers-one per analog input pair (VIN1A/VIN1B through VIN4A/VIN4B). A single CONVST rising edge places all four amplifiers into hold mode at the exact same instant, freezing input signals coherently before ADC conversion begins. Aperture delay matching of ≤4 ns ensures phase alignment remains intact for downstream vector calculations.

Can the AD7865ASZ-1REEL interface directly with a 3 V microcontroller?

Yes, the AD7865ASZ-1REEL supports direct 3 V logic interfacing via its VDRIVE pin, which powers the DB0–DB13 data bus, BUSY, EOC, and FRSTDATA outputs. When VDRIVE is supplied with 3 V ±10%, the digital outputs meet TTL-compatible voltage thresholds (VOH ≥ 2.4 V, VOL ≤ 0.4 V) and drive strength requirements for 3 V processors-eliminating external level shifters in mixed-voltage systems.

What is the purpose of the H/S SEL pin on the AD7865ASZ-1REEL?

The H/S SEL (Hardware/Software Select) pin on the AD7865ASZ-1REEL determines how channel selection is configured: when pulled low, SL1–SL4 pins directly control which of the four channels are included in the conversion sequence; when pulled high, the channel select register (programmed via DB0–DB3 during a write cycle) defines the active channels. This dual-mode flexibility allows fixed-function hardware control or dynamic firmware-driven reconfiguration.

Does the AD7865ASZ-1REEL include an internal voltage reference?

Yes, the AD7865ASZ-1REEL integrates a 2.5 V ±20 mV internal reference accessible at the VREF pin. It can be used as a stable reference for the ADC core or overdriven by an external 2.5 V ±5% source for improved accuracy and temperature drift performance. A 0.1 µF decoupling capacitor is required between VREF and AGND to ensure low-noise operation and meet specified SNR and INL performance.