Texas Instruments TPS35AA17AGADDFR

Overview

TPS35AA17AGADDFR from Texas Instruments is a nano-power precision voltage supervisor with integrated timeout watchdog timer, designed for safety-critical embedded systems. It features 1.85V fixed undervoltage threshold (±1.2% accuracy), ±10% accurate programmable watchdog timeout (adjustable via external capacitor), and ultra-low 250nA typical supply current. It operates across 1.04V–6.0V VDD and supports open-drain active-low RESET output - used in infusion pumps and surgical equipment for reliable power-on reset and fault detection.

For engineers reviewing the TPS35AA17AGADDFR datasheet, TPS35AA17AGADDFR pinout, TPS35AA17AGADDFR application, or TPS35AA17AGADDFR equivalent, key selection criteria include its factory-programmed 1.85V supervision threshold, capacitor-programmable watchdog timing (scaling up to 256×), latched output option, and SOT-23-8 (DDF) package compatibility with space-constrained medical and industrial control designs.

Technical Context

The TPS35AA17AGADDFR implements a precision analog comparator-based undervoltage detection circuit with 5% typical hysteresis and a digitally controlled timeout watchdog timer using an internal oscillator and external CWD capacitor. Its dual-function architecture ensures that voltage supervisor faults take priority over watchdog events - RESET remains asserted during VDD < VIT−, disabling watchdog monitoring until supply recovery and tD delay completion.

This device belongs to the TPS35 family's Pinout Option A configuration (per Figure 5-1), supporting CRST and CWD capacitor programming, MR input, and combined RESET output (no independent WDO pin). It uses SET0 logic input for watchdog enable/disable and scaling factor selection (1×, 128×, or 256×), with startup delay disabled ('A' in naming nomenclature).

Key Specifications

Pinout & Package

TPS35AA17AGADDFR is packaged in an 8-pin SOT-23 (DDF) with 2.90mm × 1.60mm body size, optimized for high-density PCB layouts in medical and industrial modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor + watchdog timer applications.

Compared with TPS35DA40GCJDDFR and TPS35JE42IADDSER, the TPS35AA17AGADDFR uniquely combines 1.85V precision supervision, capacitor-programmable timing, and SOT-23-8 accessibility - making it optimal for battery-powered medical devices requiring configurable fault response and tight voltage margining.

Availability

TPS35AA17AGADDFR is available at Aetrix Electronics and suitable for infusion pump control, surgical equipment monitoring, and HVAC controller supervision requiring stable component supply and long-term medical-grade lifecycle support.

Supply support for TPS35AA17AGADDFR 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 delivering analog and embedded processing solutions for industrial, automotive, and medical applications.

The TPS35 product line delivers ultra-low-power, high-accuracy voltage supervisors with integrated watchdog timers - engineered specifically for functional safety compliance in Class II medical devices and industrial control systems.

FAQ

What is the exact undervoltage threshold voltage of the TPS35AA17AGADDFR?

The TPS35AA17AGADDFR has a fixed undervoltage threshold (V_IT−) of 1.85V with ±1.2% accuracy across –40°C to 125°C. This value is factory-programmed and cannot be adjusted. It is optimized for supervision of 1.8V microcontroller domains and matches the 'AA17' segment of the part number (AA = 1.85V). The TPS35AA17AGADDFR uses internal precision resistive division and bandgap reference to maintain this accuracy without external components.

Does the TPS35AA17AGADDFR support independent watchdog output (WDO) pin functionality?

No, the TPS35AA17AGADDFR uses Pinout Option A (per TI documentation), which provides only a combined RESET output - the internal watchdog timeout signal is ANDed with the voltage supervisor output. There is no dedicated WDO pin. If independent watchdog signaling is required, consider alternatives like TPS35DA40GCJDDFR (Pinout D) or TPS35JE42IADDSER (Pinout J), both of which offer separate WDO functionality not present in the TPS35AA17AGADDFR.

How is the watchdog timeout programmed on the TPS35AA17AGADDFR?

The watchdog timeout on the TPS35AA17AGADDFR is programmed using an external capacitor connected between the CWD pin and GND. The nominal timeout is determined by CWD capacitance and internal oscillator calibration, with ±10% maximum accuracy. SET0 selects scaling factors: logic high enables 128× or 256× extension. The TPS35AA17AGADDFR does not support factory-fixed watchdog values - all timing is capacitor-based per its 'A' suffix in the naming convention.

What package type and footprint does the TPS35AA17AGADDFR use?

The TPS35AA17AGADDFR is supplied in an 8-pin SOT-23 package designated DDF, with nominal body dimensions of 2.90mm × 1.60mm. It is compatible with standard SOT-23-8 reflow profiles and pick-and-place tooling. This package provides full access to MR, CWD, CRST, SET0, WDI, RESET, VDD, and GND - unlike the 6-pin WSON variants (e.g., DSE) that omit CRST or CWD pins. The TPS35AA17AGADDFR's DDF package supports capacitor-based programmability essential for its design flexibility.

Can the TPS35AA17AGADDFR operate from a 1.2V supply rail?

Yes, the TPS35AA17AGADDFR supports VDD down to 1.04V, making it fully operational from a 1.2V supply. At this voltage, it maintains 1.85V supervision threshold detection (via internal charge pump or ratio-metric reference), delivers 250nA typical supply current, and asserts RESET when VDD falls below 1.85V - enabling use in ultra-low-voltage energy-harvesting or coin-cell-powered subsystems. The TPS35AA17AGADDFR's specification sheet confirms functionality across the full 1.04V–6.0V range with no derating.