Texas Instruments TPS3126E18DBVR

Overview

TPS3126E18DBVR from Texas Instruments is an ultra-low-voltage processor supervisory circuit with 1.71 V nominal reset threshold (V_IT–), 180 ms power-on reset delay, manual reset input (MR), and open-drain active-low RESET output. It operates down to 0.9 V supply voltage, draws 14 µA typical supply current, and is rated for –40°C to +85°C. It monitors 1.8 V rails in battery-powered DSP and microcontroller systems requiring reliable power sequencing and fault recovery.

For engineers reviewing the TPS3126E18DBVR datasheet, TPS3126E18DBVR pinout, TPS3126E18DBVR application, or TPS3126E18DBVR equivalent, key selection criteria include its 1.71 V threshold tolerance (±60 mV), MR-triggered reset capability, open-drain output topology, and SOT-23-5 package compatibility with space-constrained portable designs.

Technical Context

The TPS3126E18DBVR integrates voltage supervision and manual reset functionality without watchdog timer support. Its internal voltage divider sets a fixed 1.71 V negative-going threshold (V_IT–) with 20 mV hysteresis, ensuring stable reset assertion/deassertion during supply ramp-up/down. The device asserts RESET low when V_DD falls below V_IT–, and holds it low for 180 ms after V_DD rises above V_IT+ = V_IT– + V_HYS.

RESET remains invalid below 0.9 V V_DD; the MR pin accepts logic-low signals to force immediate reset regardless of supply voltage or timing state. The open-drain output requires an external pull-up and supports wired-OR configurations in multi-rail systems.

Key Specifications

Pinout & Package

SOT-23-5 package (2.90 mm × 1.60 mm body size), surface-mount, RoHS-compliant, moisture sensitivity level 1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3126E18DBVR, TPS3125E18DBVR lacks open-drain flexibility but offers stronger drive strength, while TPS3808G18DBVR trades fixed-threshold accuracy and ultra-low current for configurability-making TPS3126E18DBVR optimal for cost-sensitive, space-constrained 1.8 V rail supervision with shared reset architecture.

Availability

TPS3126E18DBVR is available at Aetrix Electronics and suitable for battery-powered IoT nodes, industrial PLC I/O modules, medical wearable sensor hubs, and automotive BCM subsystems requiring stable component supply across production lifecycles.

Supply support for TPS3126E18DBVR 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 for industrial, automotive, and personal electronics markets.

The TPS312x family targets low-voltage processor supervision in space- and power-constrained systems, emphasizing minimal external components, wide supply range, and robust reset timing for DSP, MCU, and FPGA-based platforms.

FAQ

What is the exact reset threshold voltage of the TPS3126E18DBVR?

The TPS3126E18DBVR has a guaranteed negative-going input threshold voltage (V_IT–) of 1.65 V to 1.77 V at TA = –40°C to +85°C, with a typical value of 1.71 V. This corresponds to a 5% below-nominal 1.8 V rail, enabling precise undervoltage detection without external calibration.

Does the TPS3126E18DBVR include a watchdog timer?

No, the TPS3126E18DBVR does not include a watchdog timer. It belongs to the TPS3125/3126 variant group, which provides manual reset (MR) and open-drain RESET but omits WDI functionality. Watchdog capability is present only in TPS3123/3124/3128 devices.

What is the function of Pin 4 on the TPS3126E18DBVR?

Pin 4 on the TPS3126E18DBVR is a no-connect (NC) terminal. It is unbonded inside the package and serves no electrical purpose. PCB layout guidelines recommend leaving it floating or connecting it to ground for mechanical stability-never to a signal or supply net.

Can the TPS3126E18DBVR operate from a 0.9 V supply?

Yes, the TPS3126E18DBVR is fully specified to operate from 0.9 V to 3.3 V. At 0.9 V, it draws 14 µA typical supply current and maintains valid RESET assertion/deassertion behavior, making it suitable for ultra-low-voltage backup domains and energy-harvesting systems.

Is the RESET output of the TPS3126E18DBVR push-pull or open-drain?

The RESET output of the TPS3126E18DBVR is open-drain active-low. It requires an external pull-up resistor to the desired logic voltage (e.g., 1.8 V or 3.3 V) and supports wired-OR connections with other reset sources-a key differentiator from push-pull variants like TPS3125E18DBVR.