Texas Instruments TPS3126E12DBVT

Overview

TPS3126E12DBVT from Texas Instruments is an ultra-low-voltage supervisor IC with active-high reset output, 1.14 V nominal threshold (±4% over temperature), 180 ms fixed reset delay, manual reset input (MR), and open-drain RESET output. It monitors 1.2 V rails in battery-powered DSP and microprocessor systems where supply integrity and watchdog supervision are critical.

For engineers reviewing the TPS3126E12DBVT datasheet, TPS3126E12DBVT pinout, TPS3126E12DBVT application, or TPS3126E12DBVT equivalent, key selection criteria include its 1.14 V threshold accuracy, MR-triggered reset capability, open-drain output topology, 14 µA supply current at 0.9 V, and SOT-23-5 package compatibility with space-constrained embedded designs.

Technical Context

The TPS3126E12DBVT implements a precision voltage comparator with internal hysteresis (20 mV) to prevent false resets during supply transients, and integrates a manual reset input that forces active-high RESET assertion independent of VDD level. Its open-drain output supports wired-OR configurations and pull-up flexibility across diverse logic families.

This device belongs to the TPS312x family variant with E-suffix threshold (–5% of nominal 1.2 V = 1.14 V), no watchdog timer (unlike TPS3123/3124/3128), and active-high push-pull output disabled-instead configured as open-drain per Table 4-1 and Figure 5-3. It operates from 0.9 V to 3.3 V across –40°C to +85°C.

Key Specifications

Pinout & Package

TPS3126E12DBVT uses a 5-pin SOT-23 (DBV) package with 2.90 mm × 1.60 mm body size and standard lead pitch. Pin 1 is RESET (active-high open-drain), Pin 2 is GND, Pin 3 is MR (manual reset input), Pin 4 is unused (no WDI function), and Pin 5 is VDD.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3126E12DBVT, TPS3125E12DBVT offers simpler interface for point-to-point reset but sacrifices bus-sharing capability, while TPS3808G12DBVR trades off MR functionality and package size for programmability and lower current-making TPS3126E12DBVT optimal for cost-sensitive, space-constrained, multi-device reset architectures.

Availability

TPS3126E12DBVT is available at Aetrix Electronics and suitable for industrial automation, medical wearables, automotive body electronics, and wireless sensor gateways requiring stable component supply and long-term lifecycle support.

Supply support for TPS3126E12DBVT 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 and embedded processing solutions, with over 90 years of innovation in power management, signal chain, and real-time control ICs.

The TPS312x family was designed specifically for ultra-low-voltage supervision in DSP, MCU, and FPGA-based systems-emphasizing sub-1 V operability, integrated manual reset, and configurable reset topologies for industrial and portable applications.

FAQ

What is the exact reset threshold voltage of the TPS3126E12DBVT?

The TPS3126E12DBVT has a nominal reset threshold of 1.14 V, corresponding to –5% of the 1.2 V nominal supply voltage (per E-suffix designation). Electrical Characteristics table 6.5 specifies this as 1.10 V (min) to 1.18 V (max) over –40°C to +85°C, with 20 mV hysteresis ensuring stable release behavior. This value is factory-trimmed and does not require external components.

Does the TPS3126E12DBVT include a watchdog timer function?

No, the TPS3126E12DBVT does not include a watchdog timer. Per Device Comparison section 4 and Functional Block Diagram Figure 7-1, watchdog input (WDI) is absent in TPS3125/3126 variants. The TPS3126E12DBVT provides only supply voltage supervision and manual reset (MR) functionality-unlike TPS3123/3124/3128 which integrate watchdog timers.

What is the function of Pin 4 on the TPS3126E12DBVT?

Pin 4 on the TPS3126E12DBVT is an unconnected (NC) terminal. As confirmed in Table 5-1 and Figure 5-3, this pin is not bonded internally and serves no electrical function. TI recommends leaving it floating or connecting it to GND per PCB layout best practices to minimize parasitic coupling-no external circuitry should be attached.

Can the TPS3126E12DBVT operate reliably at 0.9 V supply?

Yes, the TPS3126E12DBVT is fully specified to operate at 0.9 V minimum supply voltage (per Section 6.3 Recommended Operating Conditions). At this voltage, it delivers 14 µA typical supply current and maintains valid RESET assertion/deassertion with 1.14 V threshold detection. The device guarantees functional reset behavior down to 0.9 V, enabling use in ultra-low-power sleep modes.

Is the RESET output of the TPS3126E12DBVT push-pull or open-drain?

The RESET output of the TPS3126E12DBVT is open-drain, as confirmed in Table 4-1 (Reset Output Topologies) and Figure 5-3 (Pin Configuration). This differs from TPS3125 (push-pull) and enables wired-OR reset networks, mixed-voltage interfacing, and flexible external pull-up selection-critical for systems with multiple voltage domains sharing a common reset bus.