Analog Devices Inc. AD7865BSZ-1

Overview

AD7865BSZ-1 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 full temperature range - used in industrial motor control and power metering where phase-coherent multi-channel acquisition is critical.

For engineers reviewing the AD7865BSZ-1 datasheet, AD7865BSZ-1 pinout, AD7865BSZ-1 application, or AD7865BSZ-1 equivalent, key selection considerations include simultaneous sampling capability, aperture delay matching ≤4 ns, bipolar input support, parallel 14-bit interface timing, and compatibility with 3 V or 5 V digital logic via VDRIVE.

Technical Context

The AD7865BSZ-1 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 configurable channel sequence (hardware or software selected) support deterministic timing in real-time control loops.

It supports dual-mode operation: reading data either after each individual conversion (EOC-triggered) or after the full sequence completes (BUSY-triggered), with strict timing windows (e.g., t6 = 35 ns data access time at VDRIVE = 5 V) ensuring reliable interfacing to microcontrollers and DSPs without wait states.

Key Specifications

Pinout & Package

The AD7865BSZ-1 is housed in a 44-lead Plastic Quad Flatpack (PQFP) measuring 10 mm × 10 mm with 0.8 mm lead pitch. The package features separate analog (AGND) and digital (DGND) ground pins, dedicated AVDD/DVDD supplies, and VDRIVE for flexible 3 V/5 V I/O interfacing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7865BSZ-1, AD7656ASTZ offers higher resolution and two extra channels at the cost of increased power and no integrated reference, while ADS8588SIPM provides greater channel density and smaller package but replaces deterministic parallel timing with serial protocol latency - making AD7865BSZ-1 optimal for 4-channel, low-jitter, self-contained industrial control nodes.

Availability

AD7865BSZ-1 is available at Aetrix Electronics and suitable for AC motor control, uninterruptible power supplies, and industrial power metering requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for AD7865BSZ-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 is a global semiconductor company specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and control.

The AD7865 product line was designed specifically for industrial real-time systems requiring phase-coherent multi-channel data acquisition - emphasizing simultaneous sampling integrity, robust input protection, and seamless microprocessor interfacing.

FAQ

What input voltage ranges does the AD7865BSZ-1 support?

The AD7865BSZ-1 supports ±10 V and ±5 V bipolar input ranges exclusively. This is defined by its -1 variant suffix and confirmed in the Ordering Guide and General Description sections of the datasheet. It does not support unipolar (0 V to 5 V) or ±2.5 V ranges - those are assigned to AD7865BSZ-2 and AD7865BSZ-3 respectively. Input overvoltage tolerance reaches ±18 V on the ±10 V range, protecting against transients without damage.

How does the AD7865BSZ-1 achieve simultaneous sampling across four channels?

The AD7865BSZ-1 achieves true simultaneous sampling using four independent track/hold amplifiers, one per analog input pair (VIN1A/VIN1B through VIN4A/VIN4B). A single CONVST rising edge freezes all four amplifiers at the exact same instant, preserving relative phase information. This architecture is explicitly stated in the General Description and PRODUCT HIGHLIGHTS, and validated by the ≤4 ns aperture delay matching specification - a key differentiator from multiplexed ADCs.

Does the AD7865BSZ-1 include an internal voltage reference?

Yes, the AD7865BSZ-1 includes an internal 2.5 V reference with ±20 mV maximum error over temperature and 25 ppm/°C typical temperature coefficient. The VREF pin provides access to this reference and allows overdriving with an external 2.5 V ±5% source. This integrated reference eliminates the need for external components in most industrial applications, as confirmed in the GENERAL DESCRIPTION, REFERENCE INPUT/OUTPUT specifications, and Functional Block Diagram.

What is the maximum throughput rate of the AD7865BSZ-1 when all four channels are active?

The maximum throughput rate of the AD7865BSZ-1 is 100 kSPS when all four channels are sampled and converted in sequence. This is derived from the 2.4 µs conversion time per channel multiplied by four channels (9.6 µs total), yielding ~104 kSPS theoretical, with 100 kSPS specified in the GENERAL DESCRIPTION and CONVERSION RATE section to account for setup/hold and bus timing margins. Single-channel throughput is 350 kSPS.

Can the AD7865BSZ-1 interface directly with 3 V microprocessors?

Yes, the AD7865BSZ-1 can interface directly with 3 V microprocessors using its VDRIVE pin. When VDRIVE is supplied with 3 V ±10%, the DB0–DB13 data outputs, BUSY, EOC, and FRSTDATA signals operate at 3 V logic levels while maintaining full-speed timing (t6 = 40 ns max). This capability is explicitly documented in the FEATURES list, LOGIC OUTPUTS table, and PIN FUNCTION DESCRIPTIONS - enabling interoperability without level-shifting circuitry.