Texas Instruments ADS7961SDBTRG4

Overview

ADS7961SDBTRG4 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 multi-channel monitoring with real-time alarm triggering.

For engineers reviewing the ADS7961SDBTRG4 datasheet, ADS7961SDBTRG4 pinout, ADS7961SDBTRG4 application, or ADS7961SDBTRG4 equivalent, key selection considerations include its 16-channel count, 12-bit resolution, TSSOP-38 package footprint, GPIO-configurable alarm outputs, and compatibility with REF5025 reference voltage sources in industrial signal chains.

Technical Context

The ADS7961SDBTRG4 implements a capacitor-based SAR architecture with integrated sample-and-hold, enabling zero-latency conversion for closed-loop control. Its serial interface uses active-low CS, SCLK, SDI, and SDO signals synchronized to falling-edge CS sampling and supports both auto-sequencing across preselected channels and manual channel selection per conversion cycle.

It accepts dual supply domains: +VA (2.7–5.25 V) for analog circuitry and +VBD (1.7–5.25 V) for digital I/O, allowing glueless interfacing with diverse microcontrollers. Each of its 16 analog inputs (Ch0–Ch15) routes through an internal multiplexer to AINP/AINM, with MXO providing buffered multiplexer output for external PGA use (e.g., THS4031).

Key Specifications

Pinout & Package

ADS7961SDBTRG4 is housed in a 38-pin TSSOP package (DBT) with 9.70 mm × 4.40 mm body size, designed for surface-mount assembly and thermal performance up to 119°C/W (θ_JA).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7953SDBTR (identical functionality) and ADS8688IPWR (higher resolution but fewer channels and no per-channel alarms), ADS7961SDBTRG4 uniquely balances 16-channel density, 12-bit accuracy, autonomous alarm capability, and TSSOP-38 compatibility for space-constrained industrial DAQ designs.

Availability

ADS7961SDBTRG4 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 control systems requiring stable component supply and long-term industrial lifecycle support.

Supply support for ADS7961SDBTRG4 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-grade signal chain solutions.

The ADS79xx product line was engineered for high-channel-count, high-speed industrial data acquisition - delivering pin-compatible 8-/10-/12-bit variants in shared TSSOP/VQFN footprints to simplify design scalability and inventory management.

FAQ

What is the maximum clock frequency supported by the ADS7961SDBTRG4 serial interface?

The ADS7961SDBTRG4 supports a 20-MHz SCLK frequency, enabling full 12-bit data transfer within 1 µs per conversion cycle. This timing aligns with its 1-MSPS sample rate specification and ensures reliable communication with high-speed microcontrollers or FPGAs without oversampling penalties. The ADS7961SDBTRG4 datasheet specifies t_SU1 and t_H1 setup/hold requirements relative to SCLK edges to maintain robust SPI timing margins.

Does the ADS7961SDBTRG4 require an external reference voltage, and what are the acceptable specifications?

Yes, the ADS7961SDBTRG4 requires an external reference applied to REFP (Pin 4) and REFM (Pin 3). It is fully compatible with the REF5025 (2.5 V ±0.1 V), and supports input ranges of 0 to VREF or 0 to 2×VREF. The device's reference input resistance is specified at 100 kΩ minimum, and a 10 µF ceramic capacitor must be placed at REFP for stability, as confirmed in the ADS7961SDBTRG4 application diagrams and electrical characteristics table.

How many GPIOs does the ADS7961SDBTRG4 provide, and what functions are assigned to each?

The ADS7961SDBTRG4 provides four GPIOs (GPIO0–GPIO3) in its TSSOP-38 package. GPIO0 (Pin 37) is configured as an active-high alarm output; GPIO1 (Pin 38) as low-alarm output; GPIO2 (Pin 1) selects input range (high = 0 to 2×VREF); and GPIO3 (Pin 2) serves as active-low power-down control. These assignments are fixed per the ADS7961SDBTRG4 pin function table and cannot be remapped.

Is the ADS7961SDBTRG4 pin-compatible with other devices in the ADS79xx family?

Yes, the ADS7961SDBTRG4 shares identical pinout and register mapping with ADS7953SDBTR and ADS7957SDBTR in the 38-pin TSSOP package. All three devices support 16-channel, 12-bit, and 10-bit configurations respectively, with matching GPIO, alarm, and serial interface pin locations - enabling hardware reuse across resolution tiers without PCB redesign.

What is the power consumption of the ADS7961SDBTRG4 during active conversion and in power-down mode?

The ADS7961SDBTRG4 consumes 14.5 mW typical at 1 MSPS with +VA = 5 V and +VBD = 3 V, as measured under recommended operating conditions. In power-down mode (activated via GPIO3 or command), quiescent current drops to 1 µA maximum - verified in the ADS7961SDBTRG4 electrical characteristics section and critical for battery-powered instrumentation and isolated sensor nodes.