Texas Instruments ADS7948SRTET

Overview

ADS7948SRTET from Texas Instruments is a 10-bit, 2.57 MSPS pseudo-differential successive approximation register (SAR) analog-to-digital converter with integrated 2-channel analog multiplexer, SPI interface, and ultra-low power operation (7.5 mW at full speed). It supports 2.7–5.5 V analog and 1.65–AVDD digital supply ranges, operates from –40°C to +125°C, and targets high-throughput, battery-sensitive data acquisition in compact systems.

For engineers reviewing the ADS7948SRTET datasheet, ADS7948SRTET pinout, ADS7948SRTET application, or ADS7948SRTET equivalent, key selection criteria include its 10-bit resolution with ±0.15 LSB INL, 2.57 MSPS throughput using short-frame SPI timing, 3-mm × 3-mm WQFN-16 package, and dual-channel pseudo-differential input architecture for space-constrained industrial and medical signal chains.

Technical Context

The ADS7948SRTET implements a low-power SAR ADC core with on-chip sample-and-hold and a 2:1 analog multiplexer selecting between AIN0P/AIN0N and AIN1P/AIN1N inputs. Its conversion time is fixed at 10.5 SCLK cycles in short-frame mode, enabling 2.57 MSPS operation with a 34-MHz SCLK.

It uses a CMOS-compatible SPI interface with CS, SCLK, and SDO signals, supports automatic power-down via PDEN, and features independent analog (AVDD, REFGND) and digital (DVDD) supplies - allowing mixed-voltage system interfacing down to 1.65 V logic levels.

Key Specifications

Pinout & Package

The ADS7948SRTET is housed in a 3-mm × 3-mm, 16-pin WQFN package with wettable flanks and exposed thermal pad (RTE suffix). Pin 1 is marked by a dot; pins 9 and 10 are NC and must be externally shorted to GND per TI recommendation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit SAR ADC applications.

Compared with ADS7947SRTET and ADS7949SRTET, the ADS7948SRTET uniquely balances 10-bit precision, 2.57 MSPS throughput, and ultra-low 7.5-mW active power - making it optimal for cost-sensitive, thermally constrained, dual-channel data acquisition where 12-bit overspecification is unnecessary and 8-bit resolution is insufficient.

Availability

ADS7948SRTET is available at Aetrix Electronics and suitable for industrial motor control, portable medical sensors, optical transceiver monitoring, and automotive cabin air quality sensing requiring stable component supply across extended temperature and long product lifecycles.

Supply support for ADS7948SRTET 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 over 90 years of innovation in precision signal chain solutions.

The ADS794x family was designed for ultra-low-power, high-throughput data acquisition in space- and energy-constrained systems - emphasizing pin-compatible resolution scaling, wide supply flexibility, and robust operation from –40°C to +125°C.

FAQ

What is the maximum sample rate achievable with the ADS7948SRTET?

The ADS7948SRTET achieves a maximum sample rate of 2.57 MSPS when operated with a 34-MHz SCLK and a short 10.5-clock data frame. This exceeds the base 2-MSPS rate of the standard 16-clock frame and is validated across the full –40°C to +125°C temperature range. The ADS7948SRTET maintains full 10-bit performance and ±0.15 LSB INL at this speed.

Does the ADS7948SRTET support true differential input mode?

No, the ADS7948SRTET supports pseudo-differential input only: each channel uses one dedicated positive input (AIN0P or AIN1P) and one shared negative input (AIN0N or AIN1N) that accepts a limited ±0.2 V swing and may be grounded. It does not support fully differential signaling with complementary inputs. The ADS7948SRTET is optimized for unipolar or pseudo-differential sensor interfaces, not balanced analog transmission lines.

How does the power-down feature work on the ADS7948SRTET?

The ADS7948SRTET enters power-down mode when PDEN is high at the rising edge of CS. In this state, AVDD current drops to 2.5 µA (static) or 550 µA (dynamic with SCLK active), reducing total power from 7.5 mW to <1 µW. Power-up time is 1 µs, enabling rapid wake-up for burst-mode acquisition. This behavior is documented in the ADS7948SRTET Electrical Characteristics table under "Power-down state".

Can the ADS7948SRTET operate with a 1.8-V digital supply?

Yes, the ADS7948SRTET supports DVDD from 1.65 V to AVDD, including 1.8 V operation. Logic thresholds scale with DVDD (VIH = 0.7×DVDD, VIL = 0.3×DVDD), and SPI timing parameters (e.g., tSU1, tWH) are specified down to 1.65 V. The ADS7948SRTET maintains full 10-bit performance and 2.57 MSPS throughput at 1.8-V DVDD when paired with compatible 1.8-V microcontrollers.

What is the purpose of the REFGND pin on the ADS7948SRTET?

The REFGND pin on the ADS7948SRTET provides a dedicated low-noise return path for the external reference voltage applied to the REF pin. It must be shorted to the analog ground plane - not the main system GND - to prevent digital switching noise from modulating the reference and degrading DC accuracy. This separate return is critical to achieving the ADS7948SRTET's ±0.15 LSB INL and 61-dB SNR specifications.