Texas Instruments TPS3840DL44DBVR

Overview

TPS3840DL44DBVR from Texas Instruments is a nano-power, high-input-voltage supervisor IC with active-low open-drain reset output, 4.4V fixed threshold voltage (±1.5% accuracy), 300nA typical supply current, and user-programmable reset delay up to 6.2s via external capacitor on CT pin. It operates from 1.5V to 10V and supports industrial temperature range (–40°C to +125°C), used in battery-powered smart meters and PLC power monitoring.

For engineers reviewing the TPS3840DL44DBVR datasheet, TPS3840DL44DBVR pinout, TPS3840DL44DBVR application, or TPS3840DL44DBVR equivalent, key selection criteria include VIT- = 4.4V tolerance, open-drain RESET topology requiring external pull-up, programmable tD timing, MR input logic thresholds, and SOT23-5 thermal performance under low-Iq constraints.

Technical Context

The TPS3840DL44DBVR implements a precision bandgap-referenced comparator with built-in hysteresis (200mV typical for VIT- ≥ 3.1V) and glitch-immune detection circuitry. Its internal state machine enforces strict sequencing: RESET asserts when VDD falls below 4.4V or MR is pulled low, and releases only after VDD rises above 4.6V (4.4V + 200mV) *and* tD expires.

Reset timing is decoupled from startup behavior: tSTRT (220µs typ.) governs initial release after power-on, while tD (50µs–6.2s) is independently set by CT pin capacitance. The open-drain output requires external pull-up and exhibits <90nA leakage at 5.5V, enabling ultra-low-power system-level reset coordination.

Key Specifications

Pinout & Package

SOT-23-5 (DBV) package: 2.90mm × 1.60mm footprint, surface-mount, thermally efficient for space-constrained PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3840PL44DBVR, the TPS3840DL44DBVR offers lower system-level leakage and flexible pull-up voltage selection, while MAX6326LT44D2T trades programmability and nano-power for simpler BOM and qualification maturity in legacy designs.

Availability

TPS3840DL44DBVR is available at Aetrix Electronics and suitable for smart meter power monitoring, industrial PLC field transmitters, and portable EPOS terminals requiring stable component supply across extended temperature and ultra-low-power operation.

Supply support for TPS3840DL44DBVR 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 TPS3840 family was designed specifically for ultra-low-power voltage supervision in battery-backed and energy-harvesting systems, emphasizing nanoscale quiescent current, wide-V_IN capability, and field-programmable timing without firmware dependency.

FAQ

What is the exact threshold voltage and accuracy of the TPS3840DL44DBVR?

The TPS3840DL44DBVR has a fixed negative-going input threshold voltage (VIT-) of 4.4V with ±1.5% maximum accuracy over –40°C to +125°C and 1% typical accuracy at 25°C. This is factory-trimmed and does not require external resistors. Hysteresis is 200mV typical, yielding a VIT+ of 4.6V, ensuring robust release behavior during rising VDD transitions. The TPS3840DL44DBVR datasheet specifies these values in Section 6.5 Electrical Characteristics.

How does the CT pin configure reset delay in the TPS3840DL44DBVR?

The CT pin on the TPS3840DL44DBVR sets reset delay (tD) by connecting an external capacitor to GND. With no capacitor (CT floating), tD is 50µs minimum. A 10µF capacitor yields ~6.2s maximum delay. The relationship follows tD = 618937 × C_{CT_EXT} + 50µs, based on internal R_CT ≈ 500kΩ. The TPS3840DL44DBVR's CT pin must never be driven externally - it is high-impedance input-only.

What are the MR pin voltage thresholds for the TPS3840DL44DBVR?

The TPS3840DL44DBVR MR pin asserts reset when pulled below V_{MR_L} = 600mV (max) and releases reset when above V_{MR_H} = 0.7×VDD (min). Internal pull-up resistance is 100kΩ, allowing direct connection to 1.8V or 3.3V GPIOs without external components. Pulse width must exceed 300ns to guarantee recognition. These values are specified in the TPS3840DL44DBVR Electrical Characteristics table (Section 6.5).

Can the TPS3840DL44DBVR monitor a 9V battery directly?

Yes - the TPS3840DL44DBVR supports 1.5V to 10V VDD operation and has 12V absolute maximum rating on VDD. Its 4.4V threshold is appropriate for detecting end-of-life in 9V alkaline batteries (nominal 9V, depleted ~4.8V). No external resistor divider is needed, preserving nano-power operation. Startup delay is 220µs typical, enabling fast fault detection before system initialization completes. This capability is explicitly stated in the TPS3840DL44DBVR description section.

What is the open-drain RESET output leakage current for the TPS3840DL44DBVR?

The TPS3840DL44DBVR open-drain RESET pin exhibits ≤90nA leakage current when in high-impedance state (VDD = V_RESET = 5.5V, VDD > VIT+). This ultra-low leakage preserves signal integrity on shared reset buses and minimizes power loss in high-value pull-up configurations. Measured per JEDEC JESD8C standard, this parameter is confirmed in the TPS3840DL44DBVR Electrical Characteristics table (Section 6.5, I_LKG(OD)).