Texas Instruments ADS7959SRGET

Overview

ADS7959SRGET from Texas Instruments is an 8-bit, 8-channel, 1-MSPS serial interface SAR ADC with zero latency, programmable input ranges (0 to VREF or 0 to 2×VREF), two per-channel alarm thresholds, and GPIO0–GPIO3 support in TSSOP package. It operates from 2.7–5.25 V analog supply and interfaces gluelessly with microprocessors via CS/SCLK/SDI/SDO. Used in PLC analog input modules for real-time channel monitoring.

For engineers reviewing the ADS7959SRGET datasheet, ADS7959SRGET pinout, ADS7959SRGET application, or ADS7959SRGET equivalent, key selection considerations include its 8-channel count, 8-bit resolution, 1-MSPS throughput, TSSOP-30 package footprint, and dual-range programmability - all critical for multi-sensor industrial data acquisition systems requiring deterministic timing and alarm-triggered event response.

Technical Context

The ADS7959SRGET implements a capacitor-based SAR architecture with integrated sample-and-hold, accepting unipolar inputs via software-selectable 0–VREF or 0–2×VREF ranges. Its serial interface uses falling-edge CS for sampling and SCLK-synchronized conversion/data transfer, supporting both auto-sequencing and manual channel selection modes.

It features four individually configurable GPIOs (GPIO0–GPIO3) in the TSSOP-30 package, including dedicated alarm outputs (high/low), range control, and power-down enable. Input bandwidth is 47 MHz (3 dB), and it achieves typical power dissipation of 14.5 mW at 1 MSPS with +VA = 5 V and +VBD = 3 V.

Key Specifications

Pinout & Package

The ADS7959SRGET 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 8-bit, multi-channel ADC applications.

Compared with ADS7951SRGET and ADS7958SRGER, the ADS7959SRGET uniquely delivers full 8-channel capability with all four GPIOs in the industry-standard 30-pin TSSOP, making it the only drop-in solution for alarm-driven, range-flexible, 8-input industrial DAQ where pin compatibility and feature completeness are mandatory.

Availability

ADS7959SRGET is available at Aetrix Electronics and suitable for PLC analog input modules, optical line card monitoring, medical patient monitors, digital power supply telemetry, and high-speed closed-loop systems requiring stable component supply across extended production lifecycles.

Supply support for ADS7959SRGET 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, with decades of expertise in precision data converters and industrial-grade ICs.

The ADS79xx family - including ADS7959SRGET - was designed specifically for high-reliability, multi-channel data acquisition in programmable logic controllers, industrial I/O modules, and telecom infrastructure where zero-latency, alarm integration, and wide supply flexibility are critical.

FAQ

What is the maximum serial clock (SCLK) frequency supported by the ADS7959SRGET?

The ADS7959SRGET supports a maximum SCLK frequency of 20 MHz, as specified in Section 7.9 "Timing Requirements" of the SLAS605C datasheet. This enables full 8-bit conversion and data readout within 1 µs, aligning with its 1-MSPS sample rate. The device samples on the falling edge of CS and uses SCLK edges for bit shifting during conversion and serial communication. Exceeding 20 MHz may cause timing violations and invalid data.

Does the ADS7959SRGET require an external reference voltage, and what are the valid ranges?

Yes, the ADS7959SRGET requires an external reference applied to REFP and REFM pins. Per Section 7.8 of the datasheet, REFP must be between 2.0 V and 3.0 V (typical 2.5 V ±0.1 V), and the reference input resistance is 100 kΩ (min). The device supports two software-selectable input ranges: 0 to VREF and 0 to 2×VREF - the latter requires +VA ≥ 2×VREF to avoid clipping. REF5025 is a recommended companion reference IC.

How many GPIOs does the ADS7959SRGET provide, and what are their default functions?

The ADS7959SRGET provides four GPIOs (GPIO0–GPIO3) in its 30-pin TSSOP package. By default: GPIO0 serves as active-high alarm output, GPIO1 as active-high low-alarm output, GPIO2 as range-select input (high = 0–2×VREF, low = 0–VREF), and GPIO3 as active-low power-down input. All are programmable via internal registers per Section 8.3 of the datasheet, and their states persist through power cycles unless reconfigured.

Can the ADS7959SRGET perform simultaneous sampling across all 8 channels?

No, the ADS7959SRGET does not support true simultaneous sampling. It uses a single SAR ADC core with an internal multiplexer, meaning channels are sampled sequentially - either in auto-sequenced order or manually selected per conversion cycle. However, its zero-latency architecture ensures no pipeline delay between sampling and result availability, and the 1-MSPS rate allows sub-microsecond inter-channel spacing, which suffices for most industrial monitoring where phase coherence is not critical.

What is the power-down current specification for the ADS7959SRGET, and how is it activated?

The ADS7959SRGET achieves a typical power-down current of 1 µA, as stated in the Features section and confirmed in Section 7.8 Electrical Characteristics. Power-down is activated by driving GPIO3 low (active-low), or alternatively via SPI command (see Section 8.4 Device Functional Modes). In this state, the analog core, reference buffer, and digital interface are disabled while retaining register contents. Wake-up occurs on GPIO3 high or CS assertion, with full operation restored in <1 µs.