Texas Instruments TPS3831A09DQNT

Overview

TPS3831A09DQNT from Texas Instruments is an ultralow-power voltage supervisor IC designed for single-rail 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 valid operation down to 0.6 V VDD - enabling reliable power-on reset in single-cell alkaline or lithium applications.

For engineers reviewing the TPS3831A09DQNT datasheet, TPS3831A09DQNT pinout, TPS3831A09DQNT application, or TPS3831A09DQNT equivalent, key selection criteria include its 0.9 V threshold accuracy (±1% at 25°C), 200 ms reset delay, −40°C to +85°C operating range, manual reset (MR) input support, and X2SON-4 package compatibility with space-constrained portable designs.

Technical Context

The TPS3831A09DQNT implements a precision comparator-based supervision architecture with built-in hysteresis (54 mV typical) to prevent chatter during supply recovery. Its internal sampling scheme draws only ~15 µA for 200 µs per cycle, sustaining average current at 150 nA while maintaining accurate threshold detection across temperature.

Unlike the TPS3839 variant, the TPS3831A09DQNT includes a dedicated MR input pin that accepts logic-low assertion (≤0.3×VDD) to force RESET low independently of VDD level - supporting system-initiated resets in microcontroller-based designs without external pull-down circuitry.

Key Specifications

Pinout & Package

X2SON-4 (DQN) package: 1.00 mm × 1.00 mm, 0.4 mm pitch, thermal pad on bottom for enhanced thermal performance and mechanical stability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3839A09DBZR, the TPS3831A09DQNT adds MR functionality in a smaller 1-mm² package but requires one additional PCB trace; versus MAX6375XR29+T, it delivers 8× lower supply current and guaranteed operation below 1 V - making it superior for ultra-low-power, single-cell systems requiring robust reset control.

Availability

TPS3831A09DQNT is available at Aetrix Electronics and suitable for portable medical devices, smart utility meters, and industrial edge sensors requiring stable component supply with long-lifecycle assurance.

Supply support for TPS3831A09DQNT 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 specializing in analog and embedded processing technologies, with leadership in low-power design and high-reliability industrial components.

The TPS383x product line was developed specifically for ultralow-power supply monitoring in battery-operated and energy-harvesting systems - prioritizing nanoscale current consumption, sub-1-V operation, and factory-trimmed accuracy over speed or feature density.

FAQ

What is the minimum VDD voltage at which TPS3831A09DQNT guarantees valid RESET output?

The TPS3831A09DQNT guarantees a defined RESET logic state for VDD ≥ 0.6 V, as specified by the V(POR) parameter in the Electrical Characteristics table. Below 0.6 V, the RESET output is undefined and must not be relied upon for system control. This capability enables reliable operation during deep battery discharge in single-cell applications, where other supervisors typically fail to assert reset.

Does TPS3831A09DQNT require an external bypass capacitor, and why?

Yes - TI recommends a 0.1 µF ceramic capacitor placed close to the VDD pin of the TPS3831A09DQNT. Although average supply current is only 150 nA, the device draws ~15 µA for ~200 µs during periodic voltage sampling. Without local capacitance, this transient current can cause voltage droop on high-impedance supplies (e.g., battery + trace resistance), potentially triggering false resets. The capacitor maintains VDD stability during sampling events.

How does the MR pin function on TPS3831A09DQNT, and what happens after release?

The MR pin on TPS3831A09DQNT is an active-low asynchronous input. When pulled ≤0.3×VDD, it forces RESET low immediately - independent of VDD level. After MR returns high, RESET remains low for the full reset delay time (td = 120–350 ms, typ. 200 ms) before deasserting, provided VDD is above the 0.9 V threshold. This ensures consistent reset pulse width regardless of MR assertion duration.

Can TPS3831A09DQNT be used with a 1.8 V microcontroller's bidirectional reset pin?

Yes, but a series current-limiting resistor (e.g., 100 Ω to 1 kΩ) must be placed between the TPS3831A09DQNT RESET pin and the MCU's bidirectional reset pin. This prevents excessive current flow if both devices attempt to drive the line simultaneously - especially during MCU reset release when its internal weak pull-up may conflict with the TPS3831A09DQNT's push-pull output. TI documents this configuration in Figure 16 of the datasheet.

What is the hysteresis voltage of TPS3831A09DQNT, and why does it matter?

The TPS3831A09DQNT has a typical hysteresis voltage (Vhys) of 54 mV, resulting in a total window of ~0.954 V for release after reset assertion. This hysteresis prevents oscillatory reset behavior during slow VDD recovery near the 0.9 V threshold - a critical feature in systems with weak or unregulated supplies where voltage may linger near trip point. Hysteresis is factory-trimmed and stable over temperature.