Texas Instruments ADS8327IRSAR

Overview

ADS8327IRSAR from Texas Instruments is a 16-bit, 500-kSPS unipolar-input SAR analog-to-digital converter with integrated sample-and-hold, SPI/DSP-compatible serial interface, and built-in conversion clock. It delivers ±2 LSB max INL, ±1 LSB max DNL, 91 dB SNR at 10 kHz, and operates from 2.7 V to 5.5 V analog supply. It is used in precision data acquisition systems requiring low power and high DC/AC accuracy.

For engineers reviewing the ADS8327IRSAR datasheet, ADS8327IRSAR pinout, ADS8327IRSAR application, or ADS8327IRSAR equivalent, key selection considerations include unipolar input range (0 V to VREF), 4×4 QFN-16 package, deep power-down mode (2–50 nA), programmable EOC/INT polarity, and daisy-chain capability for multi-converter systems.

Technical Context

The ADS8327IRSAR implements a capacitor-based successive approximation register (SAR) architecture with inherent sample-and-hold functionality. Its conversion logic uses an internal 10.5–12.2 MHz CCLK derived from SCLK or external source, enabling precise timing control over tCONV = 18 CCLK cycles and tSAMPLE = 3 CCLK acquisition windows.

It supports both manual and auto trigger modes, with global CONVST independent of CS, and offers three power-down states-deep, nap, and auto-nap-to optimize system-level energy efficiency. The device interfaces via CMOS-compatible digital I/O powered by a separate +VBD supply (1.65 V to 1.5×+VA), isolating noise-sensitive analog and digital domains.

Key Specifications

Pinout & Package

The ADS8327IRSAR is housed in a 4×4 mm, 16-pin QFN package (RSA) with exposed thermal pad internally connected to substrate. Pin 1 is REF+, pin 16 is REF−, and the thermal pad may be connected to AGND or left floating-must remain isolated from BDGND.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit SAR ADC applications.

Compared with ADS8328IRSAR, the ADS8327IRSAR provides simpler single-input routing and smaller PCB footprint; versus AD7682BCPZ-RL7, it offers higher throughput, integrated clocking, and deeper power-down-making it superior for compact, battery-aware, high-sample-rate systems.

Availability

ADS8327IRSAR is available at Aetrix Electronics and suitable for industrial process control, medical instrumentation, data acquisition systems, and transducer interface applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for ADS8327IRSAR 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies, with decades of expertise in precision data converters and industrial-grade IC design.

The ADS8327IRSAR belongs to TI's precision SAR ADC product line, engineered for high-resolution, low-power, and robust industrial sensing applications where DC accuracy, AC fidelity, and thermal stability are critical.

FAQ

What is the maximum external SCLK frequency supported by the ADS8327IRSAR?

The ADS8327IRSAR supports SCLK up to 50 MHz when used solely as an I/O clock. When SCLK also serves as the conversion clock, the valid range is 1–21 MHz. This dual-mode flexibility allows designers to optimize between high-speed data transfer and precise internal timing control. The ADS8327IRSAR's timing compliance ensures reliable operation across both configurations without additional glue logic.

Does the ADS8327IRSAR require an external reference voltage?

Yes, the ADS8327IRSAR requires an external unipolar reference applied between REF+ and REF− pins. It accepts reference voltages from 0.3 V to 4.2 V, enabling full-scale input ranges of 0 V to VREF. No internal reference is provided, so designers must select a stable, low-drift external reference-such as the REF5025 or REF6025-to achieve the specified ±0.4 mV offset error and 91 dB SNR performance of the ADS8327IRSAR.

How does the power-down functionality work in the ADS8327IRSAR?

The ADS8327IRSAR offers three distinct power-down modes: Deep (2–50 nA), Nap (0.2–0.5 mA), and Auto-Nap (self-entering after conversion). These are controlled via SPI commands written to configuration registers. In Deep mode, the entire analog core and reference buffer are disabled, while Nap retains bias for faster wake-up. The ADS8327IRSAR resumes conversion within microseconds of exit, making it ideal for duty-cycled sensor polling in energy-constrained systems.

Can the ADS8327IRSAR operate with different analog and I/O supply voltages?

Yes, the ADS8327IRSAR features independent analog (+VA: 2.7–5.5 V) and digital I/O (+VBD: 1.65–1.5×+VA) supplies. This separation allows interfacing with 1.8 V, 2.5 V, or 3.3 V microcontrollers while maintaining full analog performance at 5 V. The ADS8327IRSAR's VIH/VIL thresholds scale with +VBD, ensuring robust logic-level compatibility without level shifters-critical for mixed-voltage industrial designs.

Is the ADS8327IRSAR pin-compatible with other devices in the ADS832x family?

The ADS8327IRSAR shares the same 4×4 QFN-16 (RSA) package and pinout with ADS8328IRSAR, but differs functionally: ADS8328IRSAR replaces –IN with COM, +IN0, and +IN1 pins and adds MUX control logic. Thus, ADS8327IRSAR and ADS8328IRSAR are footprint-compatible but not functionally interchangeable without schematic and firmware updates. The ADS8327IRSAR pinout is fixed and documented in TI SLAS415E, Figure 13.