Texas Instruments ADS7955SDBTR

Overview

ADS7955SDBTR from Texas Instruments is a 10-bit, 8-channel, single-ended SAR analog-to-digital converter with 1-MSPS sample rate, zero-latency operation, and programmable input ranges (0 to VREF or 0 to 2×VREF). It features four GPIOs in TSSOP-30 package, two per-channel alarm thresholds, and serial SPI interface-designed for high-speed industrial data acquisition in PLCs and digital power supplies.

For engineers reviewing the ADS7955SDBTR datasheet, ADS7955SDBTR pinout, ADS7955SDBTR application, or ADS7955SDBTR equivalent, key selection considerations include channel count (8), resolution (10-bit), supply flexibility (+VA: 2.7–5.25 V; +VBD: 1.7–5.25 V), GPIO configurability, and alarm threshold programming capability.

Technical Context

The ADS7955SDBTR implements a capacitor-based SAR architecture with integrated sample-and-hold, accepting unbuffered analog inputs via an internal multiplexer with MXO output. Conversion is triggered on the falling edge of CS and synchronized to SCLK up to 20 MHz.

It supports both auto-sequencing across preselected channels and manual channel selection per conversion cycle. Input range selection (0–VREF or 0–2×VREF) is software-controlled via GPIO2 (Range pin), and alarm thresholds are independently programmable per channel using internal registers accessed over SPI.

Key Specifications

Pinout & Package

ADS7955SDBTR is packaged in a 30-pin TSSOP (DBT) with nominal body size 7.80 mm × 4.40 mm. All pins are electrically validated per TI SLAS605C Rev C datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7955SDBTR, ADS7953SDBT trades channel count for resolution in identical packaging, while ADS7951SDBT halves channel count without altering performance envelope - enabling scalable channel density across product variants.

Availability

ADS7955SDBTR is available at Aetrix Electronics and suitable for PLC/IPC systems, digital power supplies, medical instrumentation, and high-speed closed-loop control requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for ADS7955SDBTR 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-including ADS7955SDBTR-is designed specifically for high-speed, multi-channel industrial data acquisition, emphasizing zero-latency operation, flexible supply compatibility, and integrated alarm functionality for real-time system monitoring.

FAQ

What is the maximum serial clock frequency supported by ADS7955SDBTR?

The ADS7955SDBTR supports a maximum SCLK frequency of 20 MHz, enabling full 12-bit or 10-bit word transfers within tight timing windows. This allows the ADS7955SDBTR to sustain its rated 1-MSPS throughput while maintaining robust SPI communication with host processors such as ARM Cortex-M4 or TI C2000 microcontrollers.

Does ADS7955SDBTR require an external reference voltage?

Yes, ADS7955SDBTR requires an external precision reference applied to REFP and REFM pins. The device is specified for VREF = 2.5 V ±0.1 V (e.g., REF5025), and supports two input ranges: 0 to VREF and 0 to 2×VREF. No internal reference is provided, so ADS7955SDBTR relies entirely on external reference stability for absolute accuracy.

How many GPIOs does ADS7955SDBTR provide, and what functions do they support?

ADS7955SDBTR provides four GPIOs (GPIO0–GPIO3) in its TSSOP-30 package. GPIO2 controls input range selection (0–VREF or 0–2×VREF); GPIO3 serves as active-low power-down input; GPIO0 and GPIO1 are configurable as high/low alarm outputs. These GPIOs are individually programmable via SPI register writes, and their states persist across conversions.

Can ADS7955SDBTR perform simultaneous sampling across all eight channels?

No, ADS7955SDBTR does not support true simultaneous sampling. It uses a single SAR core with an internal multiplexer, performing sequential conversions across CH0–CH7. However, zero-latency operation ensures no pipeline delay between samples, and auto-sequencing allows deterministic, jitter-free channel cycling at up to 1 MSPS aggregate rate.

What is the purpose of the MXO pin on ADS7955SDBTR?

The MXO (Multiplexer Output) pin on ADS7955SDBTR provides buffered access to the selected analog channel before ADC conversion. This allows external signal conditioning-such as gain adjustment using a high-input-impedance PGA like THS4031-without loading the multiplexer. MXO is especially valuable in applications requiring programmable gain per channel or external anti-aliasing filtering.