Texas Instruments TPS3125J12DBVR

Overview

TPS3125J12DBVR from Texas Instruments is an ultra-low-voltage processor supervisory circuit with 1.08 V nominal reset threshold, 180 ms power-on reset delay, manual reset input (MR), and push-pull active-high RESET output. It monitors 1.2 V supply rails in battery-powered DSP and microcontroller systems, asserting reset during brownout or software hang events.

For engineers reviewing the TPS3125J12DBVR datasheet, TPS3125J12DBVR pinout, TPS3125J12DBVR application, or TPS3125J12DBVR equivalent, key selection criteria include its 0.9 V minimum operating voltage, ±15 mV hysteresis at 1.08 V threshold, -40°C to +85°C temperature range, SOT-23-5 package compatibility, and absence of watchdog timer functionality.

Technical Context

The TPS3125J12DBVR implements fixed-threshold voltage supervision using an internal resistor divider, with no external components required. Its reset assertion logic responds to VDD falling below 1.08 V (VIT−) and remains active for 180 ms after VDD rises above VIT+ = VIT− + VHYS (1.095 V).

This device integrates a manual reset input (MR) that forces active-high RESET assertion independent of supply voltage or watchdog status. Unlike TPS3123/3124 variants, it omits the WDI pin and watchdog timer, simplifying system timing control while retaining precise rail monitoring for low-power embedded applications.

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 supervisory applications.

Compared with TPS3124J12DBVR, the TPS3125J12DBVR eliminates external pull-up needs for active-high logic interfaces; compared with TPS3839G12DBVR, it offers faster reset release (180 ms vs 300 ms) at the cost of higher quiescent current-critical for responsive boot sequences in industrial controllers.

Availability

TPS3125J12DBVR is available at Aetrix Electronics and suitable for portable medical devices, industrial sensor nodes, smart building controllers, and battery-powered diagnostic equipment requiring stable component supply across long production lifecycles.

Supply support for TPS3125J12DBVR 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 power management, signal chain, and microcontrollers.

The TPS312x family delivers ultra-low-voltage supervision for DSP and processor-based systems, targeting applications where precision rail monitoring, minimal quiescent current, and compact packaging are essential-especially in battery-constrained and industrial environments.

FAQ

What is the exact reset threshold voltage of the TPS3125J12DBVR?

The TPS3125J12DBVR has a nominal reset threshold voltage (VIT−) of 1.08 V, with guaranteed limits of 1.04 V (min) and 1.12 V (max) across the full –40°C to +85°C operating temperature range. This value is factory-trimmed and does not require external calibration or adjustment.

Does the TPS3125J12DBVR include a watchdog timer function?

No, the TPS3125J12DBVR does not include a watchdog timer. It belongs to the TPS3125 variant group, which features manual reset (MR) and active-high push-pull RESET but omits the WDI pin and watchdog functionality found in TPS3123/3124/3128 devices.

What is the purpose of Pin 4 (NC) on the TPS3125J12DBVR?

Pin 4 on the TPS3125J12DBVR is designated NC (No Connect) and is internally unconnected. It must be left floating or tied to GND per TI's recommended PCB layout guidelines to avoid parasitic coupling or EMI susceptibility in high-density designs.

How does the manual reset (MR) input behave on the TPS3125J12DBVR?

The MR input on the TPS3125J12DBVR is active-low: pulling it to GND forces immediate assertion of the active-high RESET output, regardless of VDD level or timing state. After release, RESET deasserts only after the full 180 ms delay expires, ensuring clean system restart.

Is the TPS3125J12DBVR compatible with 0.9 V supply operation?

Yes, the TPS3125J12DBVR is fully specified down to 0.9 V supply voltage. Its internal circuitry remains functional and RESET output valid at this minimum VDD, enabling use in ultra-low-power systems such as energy-harvesting nodes or sub-1 V logic domains where other supervisors fail to operate.