Analog Devices Inc. AD7327BRUZ

Overview

AD7327BRUZ from Analog Devices is a 12-bit plus sign (13-bit) SAR analog-to-digital converter with true bipolar input capability, 8-channel multiplexing, software-selectable input ranges (±10 V, ±5 V, ±2.5 V, 0 V to +10 V), and 500 kSPS throughput. It integrates a 2.5 V internal reference, channel sequencer, and temperature indicator, and is used in industrial data acquisition systems requiring high-accuracy measurement of mixed-polarity sensor signals.

For engineers reviewing the AD7327BRUZ datasheet, AD7327BRUZ pinout, AD7327BRUZ application, or AD7327BRUZ equivalent, key selection considerations include its iCMOS process enabling ±16.5 V analog supply operation, true differential/single-ended/pseudo-differential input configuration per channel, SPI/QSPI/MICROWIRE-compatible serial interface, and low 18 mW power consumption at full speed.

Technical Context

The AD7327BRUZ employs a successive approximation register (SAR) architecture with integrated track-and-hold, supporting up to 22 MHz full-power bandwidth and 500 kSPS conversion rate using a 10 MHz SCLK. Its iCMOS process enables simultaneous high-voltage analog operation (±16.5 V supplies) and low-voltage digital logic (2.7–5.25 V).

It features independent per-channel range programming via dedicated range registers, configurable input modes (single-ended, true differential, pseudo-differential), and a 13-bit output coding format (straight binary or two's complement). The device includes a built-in temperature indicator and supports both internal (2.5 V) and external reference operation, with REFIN/OUT pin serving dual input/output function.

Key Specifications

Pinout & Package

AD7327BRUZ is housed in a 20-lead TSSOP package (4.4 mm × 6.5 mm, 0.65 mm pitch), optimized for industrial PCB layouts with separate analog/digital ground pins and isolated supply domains.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar analog-to-digital converter applications.

Compared with AD7327BRUZ, AD7329BRUZ delivers double the throughput without sacrificing accuracy or flexibility, while AD7323BRUZ reduces size and cost for simpler 4-channel systems - both share identical register mapping and software compatibility, easing migration.

Availability

AD7327BRUZ is available at Aetrix Electronics and suitable for industrial process monitoring, motor drive current sensing, test & measurement equipment, and energy metering front-end applications requiring stable component supply and long-term manufacturability.

Supply support for AD7327BRUZ 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 AD7327BRUZ belongs to the AD732x family of software-configurable, high-voltage SAR ADCs designed specifically for industrial data acquisition where true bipolar signal handling, multi-range flexibility, and robust noise immunity are critical.

FAQ

What input voltage ranges does the AD7327BRUZ support, and how are they selected?

The AD7327BRUZ supports four software-selectable input ranges per channel: ±10 V, ±5 V, ±2.5 V, and 0 V to +10 V. Selection is performed by writing to dedicated range registers via the serial interface. Each of the eight analog inputs (VIN0–VIN7) can be independently configured, allowing mixed-range operation within a single acquisition cycle - for example, measuring a ±10 V encoder signal alongside a 0–10 V pressure transducer. This eliminates external gain-switching hardware and simplifies system design.

Does the AD7327BRUZ require external components for stable operation?

Yes, the AD7327BRUZ requires specific external components for reliable performance. A 680 nF capacitor must be placed on the REFIN/OUT pin to stabilize the internal 2.5 V reference. Decoupling capacitors (typically 100 nF ceramic + 10 µF tantalum) are required on VDD, VSS, VCC, and VDRIVE relative to their respective ground planes (AGND or DGND). Additionally, proper PCB layout - including separate analog/digital ground planes tied at a single point and minimized trace lengths for high-impedance analog inputs - is essential to achieve specified SNR and CMRR performance.

Can the AD7327BRUZ interface directly with a microcontroller using standard protocols?

Yes, the AD7327BRUZ features an SPI®-/QSPI™-/DSP-/MICROWIRE™-compatible serial interface operating up to 10 MHz. It uses standard signals - CS, SCLK, DIN, and DOUT - with data clocked on the SCLK falling edge. The device outputs a 16-bit frame (3-bit channel ID + sign bit + 12-bit data) MSB-first and accepts register writes for configuration. No protocol translation is needed; it works directly with most ARM Cortex-M, Renesas RX, and TI C2000 microcontrollers using native SPI peripherals, provided timing requirements (e.g., t2 setup time) are met in firmware.

How does the AD7327BRUZ handle true differential versus single-ended measurements?

The AD7327BRUZ supports true differential, single-ended, and pseudo-differential input configurations via mode bits in the control register. In true differential mode (e.g., VIN0 as positive, VIN1 as negative), it measures the voltage difference with 13-bit resolution (FSR/8192) and achieves superior noise rejection (CMRR −79 dB). In single-ended mode, each input is referenced to AGND with 12-bit-plus-sign resolution (FSR/4096). Pseudo-differential mode uses one input as reference (e.g., VIN1) and another as signal (VIN0), offering intermediate performance - all modes are selectable per channel without hardware changes.

What power supply configurations are supported by the AD7327BRUZ?

The AD7327BRUZ requires three independent supply domains: analog (VDD = +12 V to +16.5 V, VSS = −12 V to −16.5 V), core digital (VCC = 2.7 V to 5.25 V), and interface logic (VDRIVE = 2.7 V to 5.25 V). VDD/VSS enable true bipolar input operation; VCC powers the ADC core and internal logic; VDRIVE sets the voltage level for CS, DIN, DOUT, and SCLK. VDRIVE may differ from VCC but must not exceed it by more than 0.3 V. All supplies must be properly decoupled to their respective ground planes (AGND or DGND) to meet dynamic performance specifications.