Texas Instruments TPS3123J18DBVT

Overview

TPS3123J18DBVT from Texas Instruments is an ultra-low-voltage processor supervisory circuit with 1.62 V nominal reset threshold (V_IT–), 180 ms power-on reset delay, manual reset (MR) input, and watchdog timer (WDI) functionality. It monitors 1.8 V supply rails in DSP and microprocessor systems, asserts active-low RESET during undervoltage or watchdog timeout, and operates down to 0.9 V supply voltage.

For engineers reviewing the TPS3123J18DBVT datasheet, TPS3123J18DBVT pinout, TPS3123J18DBVT application, or TPS3123J18DBVT equivalent, this device delivers verified low-voltage supervision with integrated MR control and WDI-based system-level fault detection for portable, industrial, and communications infrastructure designs.

Technical Context

The TPS3123J18DBVT implements a fixed-threshold voltage monitor with 20 mV hysteresis (V_HYS) for stable reset assertion/deassertion at V_IT– = 1.56–1.68 V. Its internal watchdog timer triggers RESET if WDI transitions are missed beyond t_tout = 0.8–2.1 s, and its MR pin forces immediate RESET assertion independent of VDD or WDI state.

RESET output is push-pull active-low, valid only when VDD ≥ 0.9 V, with propagation delays under 0.1 µs from MR to RESET and 17 µs from VDD drop to RESET assertion. The device draws just 14 µA typical supply current at 0.9 V, enabling battery-sensitive applications.

Key Specifications

Pinout & Package

TPS3123J18DBVT is housed in a 5-pin SOT-23 (DBV) package measuring 2.90 mm × 1.60 mm, optimized for space-constrained PCB layouts and compatible with standard pick-and-place equipment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3123J18DBVT, TPS3124J18DBVR offers identical supervision accuracy but removes watchdog capability while changing reset polarity; TPS3808G18DBVR trades fixed precision and MR support for adjustable threshold and higher power consumption.

Availability

TPS3123J18DBVT is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC edge nodes, 5G small cell baseband units, and smart building HVAC controllers requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for TPS3123J18DBVT 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 communications markets.

The TPS312x family was designed specifically for low-voltage DSP and processor supervision, integrating voltage monitoring, watchdog timing, and manual reset in a minimal SOT-23 footprint for space- and power-constrained systems.

FAQ

What is the exact reset threshold voltage for TPS3123J18DBVT?

The TPS3123J18DBVT has a guaranteed negative-going input threshold voltage (V_IT–) of 1.56 V minimum, 1.62 V nominal, and 1.68 V maximum across –40°C to +85°C. This 1.8 V rail-specific threshold is factory-programmed and does not require external components - ensuring consistent behavior across production lots and temperature extremes.

Does TPS3123J18DBVT support manual reset, and how is it implemented?

Yes, TPS3123J18DBVT includes a dedicated MR (manual reset) input on Pin 3. A logic-low signal on MR forces immediate active-low RESET assertion regardless of VDD level or watchdog timer state. An internal 90 kΩ pullup resistor allows single-wire interface, eliminating the need for an external pullup and simplifying board layout.

What is the watchdog timeout behavior of TPS3123J18DBVT?

The TPS3123J18DBVT watchdog timer triggers RESET if no rising or falling edge is detected on the WDI pin within 0.8–2.1 s (nominal 1.4 s). Each valid edge reinitializes the timer. During timeout, RESET remains asserted for the full 100–260 ms delay period, providing deterministic recovery from software hangs in always-on systems.

Can TPS3123J18DBVT operate below 1.0 V supply voltage?

Yes - TPS3123J18DBVT is specified to function down to 0.9 V supply voltage (VDD), with RESET output valid above this level. At 0.9 V, supply current is 14 µA typical, making it suitable for ultra-low-power applications such as energy-harvesting nodes and coin-cell–operated sensors where traditional supervisors fail to start.

What package type and dimensions does TPS3123J18DBVT use?

TPS3123J18DBVT uses the SOT-23 (DBV) package: a 5-pin surface-mount outline measuring 2.90 mm × 1.60 mm (nominal body size including pins). It is RoHS-compliant, lead-free (NIPDAU/SN finish), and rated MSL Level-1 for unlimited floor life at 260°C peak reflow - compatible with standard high-volume assembly processes.