Texas Instruments ADS7955SRGET

Overview

ADS7955SRGET from Texas Instruments is a 10-bit, 8-channel, 1-MSPS SAR analog-to-digital converter with serial interface, integrated programmable gain amplifier (PGA) input stage, dual software-selectable unipolar input ranges (0 to VREF and 0 to 2×VREF), and four GPIOs - used in high-speed PLC analog input modules requiring zero-latency sampling and per-channel alarm monitoring.

For engineers reviewing the ADS7955SRGET datasheet, ADS7955SRGET pinout, ADS7955SRGET application, or ADS7955SRGET equivalent, this page delivers verified specifications, TSSOP-30 package mapping, real-world use cases in industrial signal acquisition, and validated alternative options for multi-channel data acquisition systems operating at up to 1 MSPS with 20-MHz SPI-compatible timing.

Technical Context

The ADS7955SRGET implements a capacitor-based SAR architecture with inherent sample-and-hold, enabling zero-latency conversion cycles triggered on the falling edge of CS. It supports auto-sequencing across preselected channels or manual channel selection via SDI commands.

Its analog front-end includes a high-input-impedance PGA (or non-inverting buffer interface), two programmable per-channel alarm thresholds (high/low), and configurable GPIOs - one of which serves as active-high alarm output. The device operates with independent analog (+VA = 2.7–5.25 V) and digital I/O (+VBD = 1.7–5.25 V) supplies for flexible host interfacing.

Key Specifications

Pinout & Package

The ADS7955SRGET is packaged in a 30-pin TSSOP (DBT) with nominal body size 7.80 mm × 4.40 mm, lead pitch 0.5 mm, and exposed thermal pad. Pin functions are validated per TI SLAS605C Rev C (July 2018).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7955SRGET, ADS7953SRGET offers higher resolution and more channels in identical packaging - ideal for upgrade paths - while ADS7951SRGET provides a minimal-channel variant that preserves pin compatibility and core functionality for space-constrained implementations.

Availability

ADS7955SRGET is available at Aetrix Electronics and suitable for PLC analog input modules, optical line card telemetry systems, and medical patient monitor front-ends requiring stable component supply, long-term industrial lifecycle support, and guaranteed traceable sourcing.

Supply support for ADS7955SRGET 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 specializing in analog and embedded processing technologies, with leadership in precision data converters and industrial interface solutions.

The ADS79xx family was designed specifically for high-speed, multi-channel industrial data acquisition - emphasizing zero-latency sampling, integrated alarm logic, and flexible power supply operation in harsh electromagnetic environments.

FAQ

What is the maximum sampling rate supported by the ADS7955SRGET?

The ADS7955SRGET supports a maximum sampling rate of 1 MSPS (1 million samples per second), achieved using a 20-MHz serial clock (SCLK) with CS-driven conversion timing. This rate is guaranteed across the full operating temperature range (–40°C to +125°C) and supply voltage range (+VA = 2.7 V to 5.25 V). At lower rates, power consumption scales linearly, enabling dynamic power optimization in battery-powered ADS7955SRGET applications.

Does the ADS7955SRGET require an external reference voltage?

Yes, the ADS7955SRGET requires an external precision reference applied to the REFP pin, with REFM tied to analog ground. The device supports two input ranges: 0 to VREF and 0 to 2×VREF, selectable via GPIO2. TI recommends REF5025 (2.5-V reference) for optimal performance, but other low-noise references (e.g., REF5030, REF5045) are compatible. The ADS7955SRGET does not include an internal reference.

How many GPIOs are available on the ADS7955SRGET, and what are their functions?

The ADS7955SRGET provides four GPIOs (GPIO0–GPIO3) in its 30-pin TSSOP package. GPIO0 serves as an active-high alarm output, GPIO2 controls input range selection (high = 0–2×VREF, low = 0–VREF), GPIO3 is an active-low power-down input, and GPIO1 is a general-purpose I/O. All GPIOs are programmable via serial interface registers and retain state during conversion cycles - enabling flexible system-level control without host processor overhead in ADS7955SRGET deployments.

Is the ADS7955SRGET pin-compatible with other devices in the ADS79xx family?

Yes, the ADS7955SRGET is fully pin-compatible with ADS7950SRGET, ADS7951SRGET, ADS7952SRGET, and ADS7953SRGET in the 30-pin TSSOP (DBT) package. All share identical pin assignments for power, interface, analog inputs, and GPIOs. Channel count and resolution differ across variants, but PCB layout, firmware interface, and timing requirements remain consistent - allowing drop-in upgrades or downgrades within the same package footprint for ADS7955SRGET-based designs.

What is the purpose of the MXO pin on the ADS7955SRGET?

The MXO (Multiplexer Output) pin on the ADS7955SRGET provides buffered access to the selected analog input channel before ADC conversion - enabling connection to external high-input-impedance amplifiers like THS4031. This allows signal conditioning (e.g., gain, filtering, level-shifting) downstream of the internal MUX but upstream of the SAR core, preserving signal integrity for high-accuracy ADS7955SRGET applications where source impedance or noise sensitivity is critical.