Texas Instruments TPS3831A09DQNR

Overview

TPS3831A09DQNR from Texas Instruments is an ultralow-power voltage supervisor IC designed for single-supply monitoring in battery-critical systems. It features a factory-trimmed 0.9 V reset threshold, 150 nA typical supply current at 25°C, push-pull RESET output, and operates across –40°C to +85°C. It is used to ensure reliable power-on reset and brownout protection in portable medical and metering devices.

For engineers reviewing the TPS3831A09DQNR datasheet, TPS3831A09DQNR pinout, TPS3831A09DQNR application, or TPS3831A09DQNR equivalent, key selection considerations include its 0.9 V threshold accuracy (±1%), 200 ms reset delay, manual reset (MR) input support, and compatibility with sub-1V supply rails down to 0.6 V for valid output assertion.

Technical Context

The TPS3831A09DQNR implements a precision comparator-based supervision architecture with internal hysteresis (54 mV typical) and a dedicated manual reset input. Its sampling-based sensing enables ultralow quiescent current while maintaining accurate threshold detection across temperature.

It asserts an active-low RESET signal when VDD falls below 0.9 V (VIT–), holds RESET low for ≥120 ms after VDD rises above the threshold plus hysteresis, and supports MR-driven reset assertion independent of VDD level - all while consuming only 150 nA typical supply current.

Key Specifications

Pinout & Package

X2SON-4 (DQN) package: 1.00 mm × 1.00 mm, 4-pin, thermal pad on bottom. Pin 1 = VDD, Pin 2 = GND, Pin 3 = RESET, Pin 4 = MR. Thermal pad must be connected to ground for mechanical stability and thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3831A09DQNR, TPS3839A09DBZR offers identical supervision performance in a smaller footprint but removes MR functionality, while MAX6375XR22+T trades precision low-voltage monitoring for higher threshold and significantly higher current - making it unsuitable for 0.9 V alkaline or long-life battery applications.

Availability

TPS3831A09DQNR is available at Aetrix Electronics and suitable for portable medical devices, industrial metering, wearable electronics, and wireless sensor nodes requiring stable component supply over extended production lifecycles.

Supply support for TPS3831A09DQNR 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 delivering analog and embedded processing solutions, with leadership in low-power design and precision analog IP.

The TPS383x product line was developed specifically for ultralow-power voltage supervision in battery-operated equipment, targeting applications where nanoscale current budgets and sub-1V threshold accuracy are mandatory.

FAQ

What is the minimum supply voltage required for TPS3831A09DQNR to assert a valid RESET signal?

The TPS3831A09DQNR guarantees a valid RESET logic state down to VDD = 0.6 V, per its electrical characteristics table. Below this voltage, the RESET output becomes undefined. This feature ensures deterministic behavior during deep brownout conditions, which is critical for preserving data integrity in TPS3831A09DQNR-based systems such as glucose monitors and smart meters.

Does TPS3831A09DQNR support manual reset, and how is the MR pin interfaced?

Yes, TPS3831A09DQNR includes a dedicated MR (manual reset) input on Pin 4. Pulling MR low forces RESET low regardless of VDD level. The pin has an internal 20 kΩ pullup to VDD, so it may be left unconnected if unused. When driven by an open-drain GPIO, ensure the driving logic can sink sufficient current to overcome the pullup and maintain MR < 0.3×VDD for assertion. This MR functionality is absent in the pin-compatible TPS3839A09DBZR variant.

What is the reset delay time of TPS3831A09DQNR, and is it adjustable?

The TPS3831A09DQNR has a fixed reset delay time (td) of 200 ms typical, with a guaranteed range of 120 ms to 350 ms across temperature and voltage. This delay is internally generated and not externally adjustable via capacitor or resistor. It ensures sufficient hold time for microcontroller initialization after power recovery, and applies both to power-up and MR-release events. No external components are required to set or modify this timing.

Can TPS3831A09DQNR operate from a single 1.5 V alkaline cell throughout its full discharge curve?

Yes, TPS3831A09DQNR operates across 0.9 V to 6.5 V and is explicitly designed for single-cell alkaline monitoring. Its 0.9 V threshold aligns with the end-of-discharge voltage of alkaline cells, and its ability to assert valid RESET down to 0.6 V ensures reliable operation even as the cell sags under load. TI's typical application circuit (Figure 15) demonstrates TPS3831A09DQNR controlling a boost converter shutdown at exactly 0.9 V, confirming its suitability for this use case.

What package type and mounting considerations apply to TPS3831A09DQNR?

TPS3831A09DQNR uses the X2SON-4 (DQN) package: 1.00 mm × 1.00 mm, 4-pin, with an exposed thermal pad on the bottom. The thermal pad must be soldered to a PCB copper pour connected to GND for mechanical stability and thermal performance. Standard reflow profiles for Level-1-260°C-UNLIM apply. No special stencil or placement adjustments are needed beyond standard 0201-class handling guidelines.