Analog Devices Inc. AD7605-4BSTZ

Overview

AD7605-4BSTZ from Analog Devices is a 4-channel, 16-bit simultaneous-sampling analog-to-digital data acquisition system (DAS) with true bipolar ±10 V/±5 V input ranges, 300 kSPS per channel throughput, integrated 2.5 V reference and second-order antialiasing filter, and SPI/parallel interface - used in power line monitoring, multiphase motor control, and multiaxis positioning systems.

For engineers reviewing the AD7605-4BSTZ datasheet, AD7605-4BSTZ pinout, AD7605-4BSTZ application, or AD7605-4BSTZ equivalent, key selection criteria include simultaneous sampling capability across four channels, ±16.5 V input clamp tolerance, 1 MΩ input impedance independent of sampling rate, and dual-mode interface support for FPGA/DSP host systems.

Technical Context

The AD7605-4BSTZ implements a charge redistribution successive approximation register (SAR) ADC architecture with track-and-hold amplifiers per channel, enabling true simultaneous sampling without interchannel skew. Its analog front end includes input clamp protection, 1 MΩ buffered input impedance, and a second-order low-pass antialiasing filter with −3 dB bandwidths of 23 kHz (±10 V) and 15 kHz (±5 V).

Conversion control uses dual CONVST inputs (A/B) to initiate sampling on channel pairs (V1/V2 and V3/V4), with BUSY signaling completion and FRSTDATA indicating V1 data availability. The device supports internal 2.5 V reference (±10 ppm/°C drift) or external reference via REFIN/REFOUT, and operates from single 5 V AVCC with flexible 2.3–5.25 V VDRIVE logic supply.

Key Specifications

Pinout & Package

AD7605-4BSTZ is housed in a 64-lead LQFP package (ST-64-2) with exposed pad for thermal management. Pin layout supports analog/digital ground separation, dedicated decoupling pins (REGCAP, REFCAPA/B), and dual conversion start inputs for channel-group control.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7606-4BSTZ and AD7608BSTZ, the AD7605-4BSTZ delivers optimal balance of 4-channel simultaneity, 300 kSPS speed, and integrated features like FRSTDATA and ±16.5 V clamping - making it uniquely suited for cost- and space-constrained industrial DAS where channel count and timing determinism are fixed at four.

Availability

AD7605-4BSTZ is available at Aetrix Electronics and suitable for power line monitoring, multiphase motor control, and instrumentation systems requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for AD7605-4BSTZ 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, serving industrial, automotive, communications, and healthcare markets since 1965.

The AD7605-4BSTZ belongs to Analog Devices' high-resolution data acquisition system (DAS) product line, designed specifically for industrial automation and energy infrastructure applications demanding simultaneous sampling, robust input protection, and integrated signal conditioning.

FAQ

What is the maximum analog input voltage the AD7605-4BSTZ can tolerate without damage?

The AD7605-4BSTZ analog input pins have a ±16.5 V absolute maximum rating, verified in the Absolute Maximum Ratings table (Page 9). This clamp protection operates independently of the selected input range (±10 V or ±5 V) and eliminates the need for external TVS diodes in most industrial surge environments. Operation beyond this limit risks permanent damage.

Does the AD7605-4BSTZ require an external reference, or does it include an internal one?

The AD7605-4BSTZ includes a factory-trimmed 2.5 V internal reference with ±10 ppm/°C temperature coefficient, selectable via the REF SELECT pin. When REF SELECT = high, the internal reference is enabled and appears on REFIN/REFOUT. When REF SELECT = low, the internal reference is disabled and a 2.5 V external reference must be supplied - giving designers flexibility between simplicity and ultimate accuracy.

How does the AD7605-4BSTZ achieve simultaneous sampling across all four channels?

The AD7605-4BSTZ uses independent track-and-hold amplifiers for each channel, controlled by dual asynchronous inputs: CONVST A triggers sampling on V1/V2, and CONVST B triggers V3/V4. When both pins are tied together and asserted, all four channels sample simultaneously with matched aperture delay. This architecture avoids multiplexed sampling artifacts and ensures phase coherence essential for power and motor control.

What interface options does the AD7605-4BSTZ support, and how are they configured?

The AD7605-4BSTZ supports three interface modes selected by PAR/SER/BYTE SEL and DB15/BYTE SEL pins: parallel (16-bit DB[15:0], PAR/SER/BYTE SEL = 0), serial (SPI-compatible, PAR/SER/BYTE SEL = 1 and DB15 = 0), and parallel byte (two 8-bit reads, PAR/SER/BYTE SEL = 1 and DB15 = 1). Each mode uses the same CS, RD/SCLK, and FRSTDATA signals, enabling firmware-reconfigurable host connectivity.

What is the purpose of the FRSTDATA pin on the AD7605-4BSTZ, and how is it used?

The FRSTDATA pin on the AD7605-4BSTZ asserts high to indicate that the first channel's (V1) conversion result is ready for readout - whether in parallel, serial, or byte mode. In parallel mode, it rises on the RD falling edge corresponding to V1; in serial mode, it rises on the CS falling edge. This eliminates software polling and simplifies deterministic data capture in real-time systems using the AD7605-4BSTZ.