Texas Instruments ADS831E/2K5

Overview

ADS831E/2K5 from Texas Instruments is an 8-bit, 80MHz pipelined analog-to-digital converter (ADC) with single-ended or differential input capability, internal/external reference selection, 2V_p-p/1V_p-p programmable input range, and low DNL of ±0.35LSB - deployed in medical imaging systems requiring high SNR (49dB) and fast acquisition.

For engineers reviewing the ADS831E/2K5 datasheet, ADS831E/2K5 pinout, ADS831E/2K5 application, or ADS831E/2K5 equivalent, key selection considerations include sampling rate vs. SFDR trade-offs at 10MHz input, VDRV-supplied logic level compatibility (3V/5V), aperture jitter (1.2ps rms), track-mode bandwidth (300MHz), and SSOP-20 pin-for-pin compatibility with ADS830.

Technical Context

The ADS831E/2K5 implements a 6-stage pipelined CMOS ADC architecture with digital error correction logic to guarantee no missing codes and ±0.35LSB DNL at 10MHz input. It uses a differential track-and-hold front-end that supports both single-ended input (with internal SE-to-DIFF conversion) and true differential drive, enabling spurious-free dynamic range up to 67dBFS at 1MHz.

Reference flexibility is achieved via dual top/bottom reference pins (REFT/REFB) and INT/EXT control, allowing either internal 3.0V/2.0V references or external references with ±100mV tolerance - critical for gain/offset matching across multi-channel systems. Data latency is fixed at 4 clock cycles, with output in straight offset binary format synchronized to the rising edge of CLK.

Key Specifications

Pinout & Package

ADS831E/2K5 is housed in a 20-pin SSOP (DBQ) package with 0.65mm pitch, moisture sensitivity level 2 (260°C peak reflow), and RoHS-compliant NiPdAu finish. Thermal resistance θ_JA is 115°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit, high-speed ADC applications.

Compared with ADS831E/2K5, ADS830E/2K5 trades 20MSPS speed for lower cost and power, while MAX1186EEE+ offers noise-immune LVDS output at the expense of supply complexity and loss of internal reference flexibility - making ADS831E/2K5 optimal for single-supply, reference-flexible, high-SFDR designs.

Availability

ADS831E/2K5 is available at Aetrix Electronics and suitable for medical imaging systems, video digitizing equipment, computer scanners, disk-drive read channels, and communications baseband processing requiring stable component supply and long-term production continuity.

Supply support for ADS831E/2K5 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 high-performance data converters - with over 40 years of precision ADC innovation.

The ADS831E/2K5 belongs to TI's high-speed pipeline ADC product line, designed specifically for applications demanding >45dB SNR, <1ps aperture jitter, and flexible reference architecture in compact SSOP packaging.

FAQ

What is the maximum sampling rate supported by the ADS831E/2K5?

The ADS831E/2K5 supports a maximum sampling rate of 80 million samples per second (80MSPS), validated across its full specified temperature range (–40°C to +85°C). This rate is achievable with both internal and external reference configurations, provided the convert clock (CLK) meets timing requirements: 12.5ns minimum period, <6.25ns high/low pulse width, and low jitter (<1.2ps rms). The ADS831E/2K5 maintains 49dB SNR and 67dBFS SFDR at 1MHz input under these conditions.

Does the ADS831E/2K5 require an external reference, or does it include an internal one?

The ADS831E/2K5 includes a factory-trimmed internal reference providing +3.0V (REFT) and +2.0V (REFB) outputs, enabling a 2V_p-p full-scale input range. It also supports external reference operation via the INT/EXT pin - when set HIGH, internal buffers disconnect and REFT/REFB become high-impedance inputs accepting external voltages within defined ranges (e.g., REFT = REFB + 0.8V to VS – 1.25V). This dual-mode capability makes ADS831E/2K5 suitable for both standalone and multi-channel calibrated systems.

What is the purpose of the VDRV pin on the ADS831E/2K5?

The VDRV pin on the ADS831E/2K5 supplies power exclusively to the digital output drivers, isolating logic-level switching noise from the analog +VS supply. It accepts either +3V or +5V, setting corresponding CMOS-compatible output voltage levels (e.g., VOH ≈ +2.8V at VDRV = 3V). Using VDRV = 3V reduces power dissipation by ~15mW and minimizes supply-induced jitter - critical for preserving the ADS831E/2K5's 49dB SNR. VDRV is not internally connected to +VS and must be decoupled separately.

How does the RSEL pin affect the input range of the ADS831E/2K5?

The RSEL pin on the ADS831E/2K5 selects between two full-scale analog input ranges: HIGH configures a 2V_p-p range (1.5V to 3.5V single-ended), while LOW configures a 1V_p-p range (2.0V to 3.0V). An internal 50kΩ pull-up resistor defaults RSEL to HIGH, so leaving it unconnected yields 2V_p-p. This selection adjusts the reference ladder scaling without altering REFT/REFB voltages - enabling dynamic range optimization for varying signal amplitudes in applications like video digitizing or disk-drive read channels.

Is the ADS831E/2K5 pin-compatible with other devices in its family?

Yes, the ADS831E/2K5 is pin-for-pin compatible with the ADS830E series (e.g., ADS830E/2K5), sharing identical SSOP-20 pinout, power sequencing, and interface logic. This allows direct replacement in existing designs when upgrading from 60MSPS (ADS830) to 80MSPS (ADS831), provided layout accommodates higher-speed clock routing and enhanced decoupling. However, ADS831E/2K5 is not compatible with non-pipelined or serial-output ADCs such as the ADS78xx or MAX11xx families due to fundamental architectural and pin function differences.