Texas Instruments ADS7950SBRGER

Overview

ADS7950SBRGER from Texas Instruments is a 12-bit, 4-channel, single-ended SAR analog-to-digital converter with 1-MSPS sample rate, zero-latency operation, and 20-MHz SPI-compatible serial interface. It features two software-selectable unipolar input ranges (0 to VREF and 0 to 2×VREF), programmable per-channel high/low alarm thresholds, and operates from 2.7–5.25 V analog supply. It is used in PLC analog input modules for real-time sensor monitoring.

For engineers reviewing the ADS7950SBRGER datasheet, ADS7950SBRGER pinout, ADS7950SBRGER application, or ADS7950SBRGER equivalent, key selection considerations include channel count (4), resolution (12-bit), serial interface timing (20-MHz SCLK, CS-active-low), alarm functionality per channel, and TSSOP-30 package compatibility with industrial signal acquisition layouts.

Technical Context

The ADS7950SBRGER implements a capacitor-based SAR architecture with integrated sample-and-hold, enabling true zero-latency conversion-output data is valid on the same SCLK cycle as the falling edge of CS. Its multiplexer output (MXO) provides buffered analog output of the selected channel, supporting external PGA interfacing (e.g., THS4031).

It supports both auto-sequencing (predefined channel order) and manual channel selection via SDI commands. The device uses separate analog (+VA, AGND) and digital I/O (+VBD, BDGND) supplies, allowing glueless interfacing with 1.7–5.25 V logic hosts while maintaining analog integrity through independent ground domains.

Key Specifications

Pinout & Package

The ADS7950SBRGER is housed in a 30-pin TSSOP package (7.80 mm × 4.40 mm) with exposed thermal pad. Pin functions are validated per TI SLAS605C Rev C (July 2018), Table 6 and Pin Functions section for ADS7950/ADS7954/ADS7958 variants in DBT (30-pin TSSOP) configuration.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7951SBRGER, the ADS7950SBRGER trades channel count for lower cost and reduced routing complexity in 4-sensor systems; versus ADS8684IPWR, it offers higher speed and lower power at the expense of resolution and integrated range flexibility.

Availability

ADS7950SBRGER is available at Aetrix Electronics and suitable for PLC analog input modules, optical line card telemetry, and medical patient monitor front-ends requiring stable component supply across long-lifecycle industrial programs.

Supply support for ADS7950SBRGER 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 headquartered in Dallas, Texas, specializing in analog, embedded processing, and silicon technologies for industrial, automotive, and communications markets.

The ADS79xx family was designed specifically for high-speed, multichannel data acquisition in programmable automation controllers, optical networking equipment, and precision instrumentation where zero-latency, alarm autonomy, and supply flexibility are critical.

FAQ

What is the maximum SCLK frequency supported by the ADS7950SBRGER?

The ADS7950SBRGER supports a maximum SCLK frequency of 20 MHz, enabling full 12-bit data transfer within 12 clock cycles per conversion. This timing is specified under recommended operating conditions (VBD = 1.7 V to +VA) and ensures reliable communication with high-speed microcontrollers and DSPs. The ADS7950SBRGER datasheet confirms this value in Section 7.9, Timing Requirements.

Does the ADS7950SBRGER require an external reference voltage?

Yes, the ADS7950SBRGER requires an external precision reference applied to REFP and REFM pins. It does not include an internal reference. Common choices include REF5025 (2.5 V) or REF5045 (4.5 V), with VREF stability directly impacting total unadjusted error (TUE). The ADS7950SBRGER specification table lists REFP min/max as 2.0 V to 3.0 V for 2.5 V nominal references.

How many GPIOs are available on the ADS7950SBRGER, and what are their default functions?

The ADS7950SBRGER provides four GPIOs (GPIO0–GPIO3) in its 30-pin TSSOP package. By default: GPIO2 controls input range (0 = 0–VREF, 1 = 0–2×VREF); GPIO3 is active-low power-down; GPIO0 and GPIO1 are configurable as general-purpose I/O or alarm outputs (high/low alarm). These assignments are confirmed in the Pin Functions table for ADS7950 in TI SLAS605C.

Can the ADS7950SBRGER perform simultaneous sampling across all four channels?

No, the ADS7950SBRGER does not support simultaneous sampling. It uses a single SAR ADC core with an internal multiplexer, sequentially converting CH0–CH3 in auto-sequencing mode or on-demand in manual mode. True simultaneous sampling requires multiple independent ADC cores, such as those found in TI's ADS868x series. The ADS7950SBRGER achieves 1-MSPS aggregate throughput across channels.

What is the purpose of the MXO pin on the ADS7950SBRGER?

The MXO (Multiplexer Output) pin on the ADS7950SBRGER provides a buffered analog voltage of the currently selected channel before ADC conversion. It enables external signal conditioning - for example, connecting a high-input-impedance PGA like THS4031 - without loading the channel source. This feature is explicitly documented in the Functional Block Diagram and Pin Functions sections of the ADS7950SBRGER datasheet.