Texas Instruments ADS7951SDBTR

Overview

ADS7951SDBTR 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, two software-selectable unipolar input ranges (0 to VREF and 0 to 2×VREF), and four GPIOs - designed for high-speed industrial data acquisition in PLC/IPC systems.

For engineers reviewing the ADS7951SDBTR datasheet, ADS7951SDBTR pinout, ADS7951SDBTR application, or ADS7951SDBTR equivalent, key selection considerations include its 1-MHz sample rate, zero-latency conversion, 20-MHz SPI-compatible serial interface, dual alarm thresholds per channel, and TSSOP-30 package compatibility across the ADS79xx family.

Technical Context

The ADS7951SDBTR implements a capacitor-based SAR architecture with inherent sample-and-hold, sampling on the falling edge of CS and using SCLK for conversion timing and serial data transfer. It supports both auto-sequencing of preselected channels and manual channel selection per conversion cycle.

Its analog front-end accepts differential or pseudo-differential inputs via AINP/AINM, routes through an internal multiplexer (MXO output), and includes programmable gain control via GPIO-configurable PGA. The device uses separate analog (+VA, AGND) and digital I/O (+VBD, BDGND) supplies to minimize noise coupling.

Key Specifications

Pinout & Package

ADS7951SDBTR is packaged in a 30-pin TSSOP (DBT) with 7.80 mm × 4.40 mm body size, optimized for automated assembly and thermal performance in industrial PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7953SDBT, the ADS7951SDBTR trades resolution and channel count for lower cost and reduced processing overhead; versus ADS7951IRHBT, it offers easier hand-soldering and legacy board compatibility at the expense of package density.

Availability

ADS7951SDBTR is available at Aetrix Electronics and suitable for PLC/IPC systems, optical line card monitoring, medical instrumentation, digital power supplies, and multi-channel signal monitoring requiring stable component supply and long-term industrial lifecycle support.

Supply support for ADS7951SDBTR 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 for industrial, automotive, and communications markets.

The ADS79xx product line was developed to deliver pin-compatible, scalable multichannel SAR ADCs for high-speed data acquisition in programmable automation controllers and test equipment - emphasizing zero latency, flexible input configuration, and robust industrial packaging.

FAQ

What is the maximum sample rate supported by the ADS7951SDBTR?

The ADS7951SDBTR supports a maximum sample rate of 1 MSPS. This is achieved using its 20-MHz serial clock (SCLK) and zero-latency SAR architecture, allowing one complete conversion and data transfer per microsecond. The timing is validated under recommended operating conditions with +VA = 2.7 V to 5.25 V and +VBD = 1.7 V to 5.25 V, making ADS7951SDBTR suitable for high-speed closed-loop control applications.

Does the ADS7951SDBTR require an external reference voltage?

Yes, the ADS7951SDBTR requires an external precision reference applied to the REFP and REFM pins. The device supports a nominal 2.5-V reference (e.g., REF5025), with specified operation over ±0.1 V tolerance. Reference input resistance is 100 kΩ typical, and the reference must be stable during conversion to maintain accuracy - ADS7951SDBTR does not include an internal reference.

How many GPIOs are available on the ADS7951SDBTR, and what are their functions?

The ADS7951SDBTR provides four GPIOs (GPIO0–GPIO3) in its TSSOP-30 package. GPIO2 serves as the Range select input (high = 0 to 2×VREF, low = 0 to VREF); GPIO3 is the active-low power-down (PD) input; GPIO0 and GPIO1 are fully configurable as inputs or outputs. All four support alarm output mapping and can be programmed via the serial interface - ADS7951SDBTR's GPIO flexibility enables system-level integration without additional logic.

Can the ADS7951SDBTR interface directly with a 1.8-V microcontroller?

Yes, the ADS7951SDBTR supports I/O supply voltages from 1.7 V to 5.25 V on +VBD, enabling direct interfacing with 1.8-V microcontrollers without level shifters. Its digital pins (CS, SCLK, SDI, SDO) are compliant with 1.8-V logic thresholds when +VBD = 1.8 V, and the device maintains full 20-MHz SPI timing performance - this feature simplifies design in mixed-voltage industrial systems using ADS7951SDBTR.

What is the purpose of the MXO pin on the ADS7951SDBTR?

MXO (Multiplexer Output) is an analog output pin on the ADS7951SDBTR that provides buffered access to the selected analog input channel - whether Ch0–Ch7 or AINP/AINM - before ADC conversion. This allows external circuitry (e.g., anti-aliasing filters, protection clamps, or secondary signal conditioning) to operate on the raw multiplexed signal. MXO supports high-impedance loads and is essential for applications requiring simultaneous analog monitoring and digitization - a capability confirmed in the ADS7951SDBTR functional block diagram and pin description table.