Texas Instruments TPS3128E12DBVR

Overview

TPS3128E12DBVR from Texas Instruments is an ultra-low-voltage supervisor IC with 1.14 V nominal reset threshold, watchdog timer, manual reset input, and open-drain active-low RESET output in SOT-23-5 package. It monitors supply rails down to 0.9 V, provides 180 ms power-on reset delay, draws 14 µA typical supply current, and operates from –40°C to +85°C - used for reliable system initialization in battery-powered DSP and microcontroller applications.

For engineers reviewing the TPS3128E12DBVR datasheet, TPS3128E12DBVR pinout, TPS3128E12DBVR application, or TPS3128E12DBVR equivalent, key selection criteria include its 1.14 V threshold accuracy, 1.4 s watchdog timeout, open-drain output topology, MR input compatibility, and SOT-23-5 thermal performance (R_θJA = 185°C/W) in space-constrained embedded systems.

Technical Context

The TPS3128E12DBVR integrates voltage supervision, a 1.4 s watchdog timer (t_tout), and manual reset functionality in a single 5-pin SOT-23 device. Its internal voltage divider sets a fixed 1.14 V threshold (V_IT–) with 15 mV hysteresis, and RESET remains asserted until V_DD exceeds V_IT+ = V_IT– + V_HYS, followed by a 180 ms delay before deassertion.

It supports dual-trigger watchdog operation (rising/falling edge on WDI), features a dedicated MR input that forces RESET low independently of V_DD, and uses an open-drain output requiring external pull-up - distinguishing it from push-pull variants like TPS3123J12DBVR and active-high versions such as TPS3124J12DBVR.

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 supervision applications.

Compared with TPS3128E12DBVR, TPS3123J12DBVR offers simpler drive but no open-drain versatility, while TPS3124J12DBVR serves opposite polarity logic roles without supervision redundancy - making TPS3128E12DBVR uniquely suited for robust, multi-source reset coordination in low-voltage industrial edge nodes.

Availability

TPS3128E12DBVR is available at Aetrix Electronics and suitable for industrial automation, wireless sensor networks, and factory control systems requiring stable component supply across extended product lifecycles.

Supply support for TPS3128E12DBVR 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 personal electronics markets.

The TPS312x family targets ultra-low-voltage processor supervision in space- and power-constrained systems, integrating reset generation, watchdog monitoring, and manual reset into minimal-footprint SOT-23 packages.

FAQ

What is the exact reset threshold voltage of the TPS3128E12DBVR?

The TPS3128E12DBVR has a nominal reset threshold voltage (V_IT–) of 1.14 V, with guaranteed minimum and maximum values of 1.10 V and 1.18 V respectively across –40°C to +85°C. This value is factory-trimmed and applies specifically to the "E12" variant, which denotes a –5% offset from the 1.2 V nominal rail - confirmed in Section 6.5 Electrical Characteristics of the SLVS227H datasheet.

Does the TPS3128E12DBVR support both rising and falling edges on the WDI pin?

Yes, the TPS3128E12DBVR watchdog timer is triggered by either a rising or falling edge on the WDI pin. As stated in Section 7.3.4, the timer clears on any transition, and failure to receive an edge within 1.4 s (typical) causes RESET assertion. This dual-edge sensitivity ensures compatibility with GPIO toggling or pulse-width modulated signals from diverse host processors.

Is the RESET output of the TPS3128E12DBVR push-pull or open-drain?

The TPS3128E12DBVR features an open-drain active-low RESET output, as confirmed in Table 4-1 (Reset Output Topologies) and Section 7.3.3. This differs from push-pull variants like TPS3123J12DBVR and enables wired-OR reset bus configurations, level shifting, and shared reset lines - critical for multi-rail systems where coordinated reset sequencing is required.

What is the function of the MR pin on the TPS3128E12DBVR?

The MR (Manual Reset) pin on the TPS3128E12DBVR is an active-low asynchronous input that forces the RESET output low regardless of V_DD level or watchdog status. Pulling MR low initiates reset; releasing it allows RESET to deassert after the 180 ms delay expires. This enables external fault detection - such as thermal alerts or emergency stop signals - to trigger system recovery independent of power rail health.

Can the TPS3128E12DBVR operate from a 0.9 V supply?

Yes, the TPS3128E12DBVR is fully specified to operate from 0.9 V V_DD, as stated in Section 6.3 Recommended Operating Conditions and Section 7.1 Overview. At 0.9 V, it delivers 14 µA typical supply current and maintains valid RESET assertion/deassertion behavior - making it suitable for direct connection to ultra-low-voltage regulators or partially discharged batteries where other supervisors fail to function.