Texas Instruments ADS7951SRGET

Overview

ADS7951SRGET from Texas Instruments is a 10-bit, 8-channel, 1-MSPS serial analog-to-digital converter with zero-latency SAR architecture, programmable input ranges (0 to VREF or 0 to 2×VREF), dual alarm thresholds per channel, and four GPIOs - used in PLC analog input modules for real-time voltage/current monitoring.

For engineers reviewing the ADS7951SRGET datasheet, ADS7951SRGET pinout, ADS7951SRGET application, or ADS7951SRGET equivalent, key selection considerations include its 1-MHz sampling rate, 20-MHz SPI interface timing, TSSOP-30 package footprint, GPIO-configurable alarm outputs, and compatibility with unbuffered or PGA-coupled signal chains.

Technical Context

The ADS7951SRGET implements a capacitor-based SAR ADC with integrated sample-and-hold, accepting analog supplies from 2.7 V to 5.25 V and I/O supplies from 1.7 V to 5.25 V. Its serial interface uses active-low CS, SCLK, SDI, and SDO signals with conversion triggered on the falling edge of CS.

It supports both auto-sequencing across preselected channels and manual channel selection per conversion cycle. Input range selection (0–VREF or 0–2×VREF) and two per-channel alarm thresholds are software configurable via SPI, enabling adaptive monitoring in closed-loop systems without host intervention.

Key Specifications

Pinout & Package

The ADS7951SRGET is packaged in a 30-pin TSSOP (DBT) with 7.80 mm × 4.40 mm body size, featuring exposed thermal pad for enhanced heat dissipation in high-density industrial PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multichannel ADC applications.

Compared with ADS7953SRHBT, ADS7951SRGET offers lower cost and smaller PCB area for 8-channel systems; compared with ADS7950SRGET, it doubles channel capacity without changing board layout or driver code - making it optimal for scalable I/O module families.

Availability

ADS7951SRGET is available at Aetrix Electronics and suitable for PLC/IPC analog input modules, optical line card telemetry systems, and medical instrumentation requiring stable component supply, long-term obsolescence planning, and traceable sourcing.

Supply support for ADS7951SRGET 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 and embedded processing technologies, with decades of expertise in precision data converters and industrial interface solutions.

The ADS79xx family was designed specifically for high-speed, multi-channel data acquisition in programmable logic controllers, optical networking equipment, and medical diagnostics - emphasizing zero-latency operation, flexible alarm handling, and robust SPI interoperability.

FAQ

What is the maximum sampling rate supported by the ADS7951SRGET?

The ADS7951SRGET supports a maximum sampling rate of 1 MSPS (1 million samples per second). This rate is achievable under recommended operating conditions with +VA = 5 V and +VBD = 3 V. The device maintains full 10-bit performance up to this rate, and its zero-latency architecture ensures no pipeline delay between sampling and data availability on the SDO line. ADS7951SRGET achieves this speed using a 20-MHz SPI clock with precise timing alignment per the SLAS605C datasheet.

Does the ADS7951SRGET require an external reference voltage?

Yes, the ADS7951SRGET requires an external reference voltage applied to the REFP and REFM pins. It does not include an internal reference. The device supports reference voltages such as 2.5 V ± 0.1 V (e.g., REF5025), and input ranges are defined relative to VREF (0 to VREF or 0 to 2×VREF). ADS7951SRGET's reference input resistance is specified as 100 kΩ minimum, necessitating a low-output-impedance reference source to maintain accuracy across temperature and supply variations.

How many GPIOs does the ADS7951SRGET provide, and what functions do they support?

The ADS7951SRGET provides four individually configurable GPIOs (GPIO0–GPIO3) in its 30-pin TSSOP package. These pins support input, output, or remapped functionality including input range selection (GPIO2), power-down activation (GPIO3), and alarm outputs (GPIO0 and GPIO1). ADS7951SRGET allows full software control of each GPIO direction and state via SPI register writes, enabling flexible system-level integration without additional logic components.

Is the ADS7951SRGET pin-compatible with other devices in the ADS79xx family?

ADS7951SRGET is pin-compatible with all 30-pin TSSOP variants in the ADS79xx family - specifically ADS7950SRGET (4-channel), ADS7954SRGET (10-bit, 4-channel, VQFN), and ADS7955SRGET (10-bit, 8-channel, VQFN is not pin-compatible). Within the DBT (30-pin TSSOP) group, ADS7951SRGET shares identical pinout, power sequencing, and SPI timing with ADS7950SRGET, allowing shared PCB layout and firmware abstraction layers.

What alarm features does the ADS7951SRGET support, and how are they configured?

The ADS7951SRGET supports two independently programmable alarm thresholds (high-alarm and low-alarm) per analog channel, with dedicated GPIO outputs (GPIO0 for high-alarm, GPIO1 for low-alarm). Threshold values are written via SPI to 10-bit alarm registers, and comparisons occur continuously in hardware. ADS7951SRGET generates active-high alarm pulses without host CPU involvement, enabling autonomous fault detection in safety-critical systems such as industrial shutdown controllers.