Texas Instruments TPS3128E18DBVR

Overview

TPS3128E18DBVR from Texas Instruments is an ultra-low-voltage processor supervisory IC with 1.71 V nominal reset threshold, 180 ms power-on reset delay, manual reset (MR) input, and watchdog timer (WDI) functionality. It operates down to 0.9 V supply voltage, draws 14 µA typical quiescent current, and delivers active-low open-drain RESET output in a 5-pin SOT-23 package for embedded DSP and microcontroller systems.

For engineers reviewing the TPS3128E18DBVR datasheet, TPS3128E18DBVR pinout, TPS3128E18DBVR application, or TPS3128E18DBVR equivalent, key selection criteria include its 1.71 V threshold accuracy, 1.4 s watchdog timeout, −40°C to +85°C temperature range, open-drain output topology, and compatibility with low-power portable and industrial control systems requiring reliable power-up sequencing and software hang detection.

Technical Context

The TPS3128E18DBVR integrates supply voltage monitoring, fixed 180 ms reset delay timing, manual reset assertion via MR pin, and a 0.8–2.1 s watchdog timer that triggers on missing WDI transitions. Its internal voltage divider sets a precise 1.71 V (typ) threshold with 20 mV hysteresis, ensuring stable trip points across temperature.

It uses an open-drain RESET output requiring external pull-up, supports VDD operation from 0.9 V to 3.3 V, and asserts RESET when VDD falls below VIT− or when WDI remains static beyond timeout - enabling robust fault recovery in always-on systems like factory automation controllers and wireless baseband processors.

Key Specifications

Pinout & Package

TPS3128E18DBVR is housed in a 5-pin SOT-23 (DBV) package measuring 2.90 mm × 1.60 mm, optimized for space-constrained PCB layouts in portable electronics and edge-node modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervision and watchdog applications.

Compared with TPS3123E18DBVR and TPS3823-18DBVR, the TPS3128E18DBVR uniquely combines 1.71 V threshold accuracy, integrated watchdog timer, and manual reset input in an open-drain configuration - making it optimal for systems requiring layered fault detection without adding discrete components or increasing layout complexity.

Availability

TPS3128E18DBVR is available at Aetrix Electronics and suitable for industrial PLC I/O modules, wireless sensor nodes, medical point-of-care monitors, and smart energy meters requiring stable component supply with guaranteed long-term manufacturability.

Supply support for TPS3128E18DBVR 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, embedded processing, and connectivity solutions for industrial, automotive, and consumer markets.

The TPS312x family was engineered specifically for low-voltage DSP and microcontroller systems needing precise, low-power supply supervision with integrated watchdog and manual reset - targeting portable, industrial, and communications infrastructure applications.

FAQ

What is the exact reset threshold voltage of the TPS3128E18DBVR?

The TPS3128E18DBVR has a factory-trimmed negative-going input threshold voltage (VIT−) of 1.65 V (min), 1.71 V (typ), and 1.77 V (max) across −40°C to +85°C, corresponding to a nominal 1.8 V supply rail with −5% tolerance per TI's naming convention (E = −5%). This value is set by internal precision resistors and requires no external calibration.

Does the TPS3128E18DBVR require an external pull-up resistor on the RESET pin?

Yes, the TPS3128E18DBVR features an open-drain RESET output and requires an external pull-up resistor to a valid logic rail (e.g., 3.3 V or 1.8 V). Typical values range from 4.7 kΩ to 10 kΩ. The absence of an internal pull-up ensures voltage-level flexibility and prevents contention in multi-supervisor configurations.

How does the watchdog timer in the TPS3128E18DBVR function?

The TPS3128E18DBVR watchdog timer triggers RESET if the WDI pin remains static (no rising or falling edge) for longer than its timeout period (0.8–2.1 s). Each valid edge resets the timer. Unlike windowed watchdogs, it does not require periodic pulses within a narrow interval - simplifying firmware integration while still detecting full software hangs.

Can the TPS3128E18DBVR operate reliably below 1.0 V?

Yes - the TPS3128E18DBVR is fully specified down to 0.9 V VDD and functions correctly at this minimum supply voltage, drawing only 14 µA typical current. However, RESET output validity and timing parameters (e.g., td, ttout) are guaranteed only when VDD ≥ 0.9 V; operation below this risks undefined behavior per absolute maximum ratings.

What is the purpose of the MR pin on the TPS3128E18DBVR?

The MR (manual reset) pin on the TPS3128E18DBVR allows external hardware to force a reset independently of VDD voltage or watchdog status. Pulling MR low asserts RESET immediately; releasing it (to high-impedance or VDD) causes RESET to deassert after the 180 ms delay expires. An internal 90 kΩ pull-up resistor ensures default high state when unconnected.