Texas Instruments ADS8321E/2K5G4

Overview

The ADS8321E/2K5G4 from Texas Instruments is a 16-bit SAR analog-to-digital converter with differential bipolar input, 100kHz sampling rate, ±0.018% integral linearity error, and MSOP-8 package. It operates from 4.75V to 5.25V, consumes only 4.5mW at full rate, and supports SPI/SSI-compatible serial interface - ideal for portable data acquisition and isolated sensor interfaces.

For engineers reviewing the ADS8321E/2K5G4 datasheet, ADS8321E/2K5G4 pinout, ADS8321E/2K5G4 application, or ADS8321E/2K5G4 equivalent, key selection considerations include its micro-power operation at low sample rates (1mW at 10kHz), 3µA max power-down current, differential input architecture, reference voltage flexibility (500mV to VCC/2), and compatibility with precision remote sensing systems requiring high resolution without thermal or layout-induced linearity degradation.

Technical Context

The ADS8321E/2K5G4 implements a capacitive redistribution SAR architecture fabricated in 0.6µm CMOS, enabling 16-bit conversion with no missing codes over –40°C to +85°C. Its analog front-end features fully differential inputs with 25pF input capacitance and ±1nA leakage, supporting both single-ended and differential drive configurations.

Digital timing is synchronous: conversion initiates on CS falling edge, sampling occurs over 4.5 clock cycles, conversion completes in 16 clock cycles, and 16-bit two's complement data shifts out MSB-first on DOUT synchronized to DCLOCK falling edges - with zero pipeline delay and configurable LSB-first readout after completion.

Key Specifications

Pinout & Package

ADS8321E/2K5G4 is housed in an MSOP-8 (DGK) package - 3.0mm × 3.0mm, 0.65mm pitch, exposed pad optional - optimized for compact PCB layouts and thermal performance in space-constrained modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS8322E/2K5, the ADS8321E/2K5G4 trades 0.006% FSR linearity for lower cost and identical power/performance in non-calibration applications; versus ADS8325IPW, it retains design flexibility with external reference control but requires additional passive components and layout attention to reference stability.

Availability

ADS8321E/2K5G4 is available at Aetrix Electronics and suitable for portable instrumentation, isolated sensor nodes, and multi-channel data acquisition systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for ADS8321E/2K5G4 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets.

The ADS8321E/2K5G4 belongs to TI's precision data converter product line, designed specifically for low-power, high-resolution sampling in battery-operated and isolated measurement systems where accuracy, size, and energy efficiency are co-optimized.

FAQ

What is the maximum sampling rate supported by the ADS8321E/2K5G4?

The ADS8321E/2K5G4 supports a maximum sampling rate of 100kHz, achieved with a 2.4MHz DCLOCK signal (24× oversampling). At this rate, conversion time is fixed at 16 clock cycles, and total throughput remains stable across the specified temperature range of –40°C to +85°C. The device maintains full 16-bit performance and no missing codes at this maximum rate.

Does the ADS8321E/2K5G4 require an external reference voltage?

Yes, the ADS8321E/2K5G4 requires an external reference voltage applied to the VREF pin. It accepts any stable voltage from 500mV to VCC/2 (e.g., 2.5V at VCC = 5V), which directly defines the full-scale differential input range (±VREF). The reference must be low-noise and well-bypassed with a 0.1µF ceramic capacitor placed close to the VREF pin to maintain 16-bit accuracy.

What is the power consumption of the ADS8321E/2K5G4 at 10kHz sampling rate?

At a 10kHz sampling rate, the ADS8321E/2K5G4 consumes less than 1mW average power - achieved by spending most of its time in power-down mode between conversions. This value assumes VCC = 5V, fCLK = 2.4MHz, and proper CS control. Quiescent current drops to approximately 250µA under these conditions, making it ideal for ultra-low-power portable applications.

Is the ADS8321E/2K5G4 pin-compatible with other Texas Instruments ADCs?

Yes, the ADS8321E/2K5G4 is explicitly pin-compatible with the ADS7816 and ADS7822, sharing identical MSOP-8 pinout and functional mapping. This allows direct substitution in existing designs without PCB modification, though users must verify that reference voltage range, timing constraints, and digital interface behavior align with the target application requirements.

What digital interface protocol does the ADS8321E/2K5G4 use?

The ADS8321E/2K5G4 uses a synchronous 3-wire serial interface compatible with SPI and SSI standards. It requires CS (chip select), DCLOCK (data clock), and DOUT (serial data output). Data is transmitted MSB-first on the falling edge of DCLOCK, with conversion initiated by a CS falling edge and valid data appearing after five clock cycles - no external framing or configuration registers are needed.