Texas Instruments ADS7961SRHBR

Overview

ADS7961SRHBR from Texas Instruments is a 12-bit, 16-channel, single-ended SAR analog-to-digital converter with 1-MSPS sample rate, zero-latency operation, and 20-MHz 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 high-speed PLC data acquisition systems requiring precise multi-channel monitoring.

For engineers reviewing the ADS7961SRHBR datasheet, ADS7961SRHBR pinout, ADS7961SRHBR application, or ADS7961SRHBR equivalent, key selection considerations include its 16-channel count, 12-bit resolution, TSSOP-38 package footprint, GPIO-configurable alarm outputs, and compatibility with glueless interfacing to microprocessors via CS/SCLK/SDI/SDO.

Technical Context

The ADS7961SRHBR implements a capacitor-based SAR architecture with integrated sample-and-hold, enabling true zero-latency conversion. Its multiplexer supports auto-sequencing across all 16 channels or manual channel selection per cycle, synchronized to the falling edge of CS.

It accepts dual supply domains: analog supply (+VA) from 2.7 V to 5.25 V and I/O supply (+VBD) from 1.7 V to 5.25 V, allowing direct interfacing with 1.8-V, 3.3-V, or 5-V digital hosts. The device supports two programmable alarm levels per channel and offers power-down mode with 1 μA quiescent current.

Key Specifications

Pinout & Package

The ADS7961SRHBR is housed in a 38-pin TSSOP package (9.70 mm × 4.40 mm body size) with exposed thermal pad. Pin functions are validated per TI SLAS605C Rev C (July 2018), Table 6 and Pin Functions section for ADS7961.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7961SRHBR, ADS7960SRHBR offers identical performance in a 12-channel configuration-ideal for layout reuse-while ADS8688IPWR trades channel count and alarm intelligence for higher resolution and integrated gain, shifting system-level signal conditioning responsibility.

Availability

ADS7961SRHBR is available at Aetrix Electronics and suitable for PLC/IPC systems, optical line card monitoring, medical instrumentation, digital power supplies, and high-speed closed-loop systems requiring stable component supply and long-term production continuity.

Supply support for ADS7961SRHBR 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 ADS7961SRHBR-is designed specifically for high-channel-count, high-speed industrial data acquisition, emphasizing zero-latency operation, flexible alarm handling, and robust mixed-signal interfacing in harsh environments.

FAQ

What is the maximum input frequency supported by the ADS7961SRHBR?

The ADS7961SRHBR has an input bandwidth of 47 MHz at 3 dB, but its effective usable input frequency is constrained by the 1-MSPS sampling rate. According to Nyquist theory, it accurately digitizes signals up to 500 kHz. For anti-aliasing, a front-end filter must suppress frequencies above this limit. The 47-MHz bandwidth ensures minimal passband distortion for baseband signals within specification.

Does the ADS7961SRHBR require an external reference voltage?

Yes, the ADS7961SRHBR requires an external reference applied between REFP and REFM pins. It does not include an internal reference. TI recommends the REF5025 (2.5-V precision reference) as shown in the typical application diagram. The device supports two input ranges-0 to VREF and 0 to 2 × VREF-so reference selection directly determines full-scale input span and measurement resolution.

How many GPIOs does the ADS7961SRHBR support, and what are their functions?

The ADS7961SRHBR provides four individually configurable GPIOs (GPIO0–GPIO3) in its 38-pin TSSOP package. These can be programmed as alarm outputs (high/low threshold triggers), input range selectors (Range pin), or active-low power-down controls (PD). Their function is defined via internal registers accessible over the SPI interface, enabling flexible system-level event handling without additional logic.

Is the ADS7961SRHBR pin-compatible with other devices in the ADS79xx family?

Yes, the ADS7961SRHBR is fully pin-compatible with all 38-pin TSSOP variants in the ADS79xx family-including ADS7952, ADS7953, ADS7956, ADS7957, ADS7960, and ADS7961-sharing identical pinout, package dimensions, and register map. This allows drop-in replacement across 8-/12-/16-channel and 8-/10-/12-bit variants, simplifying design scalability and inventory management.

What power supply configurations are required for proper operation of the ADS7961SRHBR?

The ADS7961SRHBR requires two independent supplies: +VA (2.7–5.25 V) for analog circuitry including the SAR core and multiplexer, and +VBD (1.7–5.25 V) for digital I/O including SPI interface and GPIOs. AGND and BDGND must be connected to separate ground planes or carefully partitioned to minimize digital noise coupling into analog measurements. Decoupling capacitors (e.g., 100 nF + 10 µF) are mandatory at each supply pin.