Texas Instruments ADS7946SRTER

Overview

ADS7946SRTER from Texas Instruments is a 14-bit, 2 MSPS dual-channel single-ended SAR analog-to-digital converter with integrated input multiplexer and sample-and-hold. It operates from 2.7 V to 5.25 V AVDD and 1.65 V to AVDD DVDD, delivers 82 dB SNR at 20 kHz, supports SPI interface, and targets high-precision data acquisition in battery-powered instrumentation.

For engineers reviewing the ADS7946SRTER datasheet, ADS7946SRTER pinout, ADS7946SRTER application, or ADS7946SRTER equivalent, this page provides verified specifications, QFN-16 package layout, real-world use scenarios in medical and optical systems, and two confirmed alternative parts with documented functional and performance differences.

Technical Context

The ADS7946SRTER implements a successive approximation register (SAR) architecture with inherent sample-and-hold, enabling precise conversion without external hold circuitry. Its two-channel single-ended input mux selects between AIN0/AIN0GND and AIN1/AIN1GND pairs under CH SEL control, with channel switching synchronized to CS timing for stable settling before sampling.

It uses a 16-clock SPI frame for data transfer, supports automatic power-down via PDEN, and maintains full dc precision (±2.5 LSB INL max) and dynamic performance (82 dB SNR, –85 dB THD) across –40°C to +125°C while consuming only 11.6 mW at 2 MSPS.

Key Specifications

Pinout & Package

ADS7946SRTER is housed in a 3 mm × 3 mm, 16-pin QFN package (RTE) with exposed thermal pad. Pin 1 is located at the top-left corner (marked by dot), and the package is lead-free and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7945SRTER, ADS7946SRTER trades differential input capability for simplified single-ended interfacing and slightly lower SNR; compared with ADS8684IPWR, it offers higher speed and smaller QFN package but requires external reference and lacks PGA functionality-making ADS7946SRTER optimal for compact, high-throughput, single-ended sensor digitization.

Availability

ADS7946SRTER is available at Aetrix Electronics and suitable for optical networking monitoring, portable medical instrumentation, and battery-powered test equipment requiring stable component supply, long-term lifecycle support, and consistent parametric performance across temperature extremes.

Supply support for ADS7946SRTER 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 ADS79xx family was designed specifically for high-speed, low-power, precision data acquisition in space-constrained, battery-sensitive, and thermally demanding applications-emphasizing integration, robustness, and ease of digital interfacing.

FAQ

What is the maximum sample rate supported by the ADS7946SRTER?

The ADS7946SRTER supports a maximum sample rate of 2 MSPS, achieved using a 40 MHz SCLK with a fixed 16-clock SPI frame. This throughput is maintained across the full operating temperature range (–40°C to +125°C) and supply voltage range (AVDD = 2.7 V to 5.25 V). The conversion time is precisely 16 SCLK cycles, and acquisition time is 80 ns-both guaranteed by design simulation and characterization.

How does the ADS7946SRTER handle channel selection between AIN0 and AIN1?

The ADS7946SRTER uses the CH SEL pin to select between its two single-ended input channels: CH SEL = Low configures the ADC to sample AIN0 and AIN0GND; CH SEL = High selects AIN1 and AIN1GND. TI specifies that the CH SEL state must be stable for at least half an SCLK cycle after the CS falling edge to ensure proper multiplexer settling before conversion begins-this timing is detailed in Figure 84 of the SBAS539B datasheet.

Can the ADS7946SRTER operate with a 1.8 V digital supply?

Yes, the ADS7946SRTER supports DVDD as low as 1.65 V, making 1.8 V fully compliant. At DVDD = 1.8 V, logic thresholds are VIH ≥ 1.26 V and VIL ≤ 0.54 V, and SDO output levels meet VOH ≥ 1.44 V and VOL ≤ 0.36 V into a 20 pF load. All timing parameters-including tSU1 (11 ns), tH1 (15 ns), and tD2 (4 ns)-are characterized and guaranteed at this voltage, enabling direct interfacing with 1.8 V FPGAs and microcontrollers.

What is the purpose of the AIN0GND and AIN1GND pins on the ADS7946SRTER?

The AIN0GND and AIN1GND pins provide dedicated ground-sense connections for each single-ended channel, allowing the ADS7946SRTER to reject local ground potential differences and common-mode noise at the source. Unlike shared ground architectures, this per-channel ground reference improves measurement accuracy-especially in systems with distributed sensors or long traces-by eliminating ground-loop errors between AIN0 and AIN1 paths. These pins must be connected to the respective sensor ground points, not to the main system GND.

Does the ADS7946SRTER include an internal voltage reference?

No, the ADS7946SRTER does not include an internal voltage reference. It requires an external reference voltage applied to the REF pin, with a valid range of 2.5 V to AVDD. The REFGND pin must be shorted to the analog ground plane and decoupled locally. This external reference architecture allows system designers to select precision references (e.g., REF5025, REF6025) matching their accuracy, temperature drift, and noise requirements-providing greater flexibility than fixed internal references.