Texas Instruments TPS3840DL25DBVR

Overview

TPS3840DL25DBVR from Texas Instruments is a nano-power, high-input-voltage supervisor IC with active-low open-drain reset output, 2.5V fixed threshold voltage (±1.5% max), 300nA typical supply current, and programmable reset delay via external capacitor on the CT pin. It monitors VDD rails up to 10V and is used in battery-powered safety-critical systems requiring reliable power-on-reset and fault detection before system startup.

For engineers reviewing the TPS3840DL25DBVR datasheet, TPS3840DL25DBVR pinout, TPS3840DL25DBVR application, or TPS3840DL25DBVR equivalent, key selection criteria include its 2.5V detection accuracy, SOT-23-5 package footprint, 50µs–6.2s user-programmable reset timing, MR input for manual reset assertion, and operation across –40°C to +125°C industrial temperature range.

Technical Context

The TPS3840DL25DBVR implements a precision bandgap-referenced comparator with built-in hysteresis (100mV typical for 2.5V threshold) and glitch immunity on both VDD and MR inputs. Its internal CT pin resistor (500kΩ typical) forms an RC time constant with an external capacitor to generate the reset delay, enabling deterministic release timing after power-up or fault recovery.

It features a dedicated MR input with logic-level thresholds (V_{MR_L} ≤ 600mV, V_{MR_H} ≥ 0.7×V_DD) and supports floating MR for automatic operation. The open-drain RESET output requires an external pull-up and delivers <200mV VOL at 2mA sink, ensuring compatibility with diverse logic families and voltage domains.

Key Specifications

Pinout & Package

SOT-23-5 (DBV) package: 2.90mm × 1.60mm footprint, surface-mount, 5-pin configuration with exposed pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3840PL25DBVR, the TPS3840DL25DBVR trades off pull-up dependency for lower leakage and broader design flexibility in mixed-voltage systems; versus MAX6326LT25D3+T, it adds critical configurability (MR, CT) and 5.8× lower supply current for battery longevity.

Availability

TPS3840DL25DBVR is available at Aetrix Electronics and suitable for grid infrastructure protection equipment, industrial PLC transmitters, fire safety systems, and portable battery-powered devices requiring stable component supply across extended temperature and long product lifecycles.

Supply support for TPS3840DL25DBVR 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, high-voltage supervision in safety-critical embedded systems-emphasizing nanoscale current consumption, wide input range, and robust timing control without external components.

FAQ

What is the exact threshold voltage and accuracy of the TPS3840DL25DBVR?

The TPS3840DL25DBVR has a fixed negative-going input threshold voltage (V_IT−) of 2.5V, with accuracy specified as ±1.5% maximum over –40°C to +125°C. Typical accuracy is ±1%, and hysteresis is 100mV typical-ensuring stable reset assertion and release without oscillation during slow VDD transitions. This specification is factory-trimmed and does not require external calibration.

How do I configure the reset delay time for the TPS3840DL25DBVR?

To configure the reset delay time for the TPS3840DL25DBVR, connect an external capacitor between the CT pin (Pin 5) and GND. With no capacitor (CT floating), the delay is 50µs minimum. Using a 100nF capacitor yields ~62ms; a 10µF capacitor achieves ~6.2s maximum. The relationship follows t_D ≈ 618937 × C_{CT_EXT} + 50µs. Always use X7R or C0G dielectric capacitors for stability.

Can the TPS3840DL25DBVR monitor a 9V battery directly without external resistors?

Yes, the TPS3840DL25DBVR can monitor a 9V battery directly without external resistors because its VDD input operates from 1.5V to 10V. Its 2.5V threshold remains accurate across this full range, and internal bandgap regulation ensures consistent performance regardless of input voltage-eliminating the need for external voltage dividers or level-shifters in 9V-powered smoke detectors or portable test equipment.

What is the function of the MR pin on the TPS3840DL25DBVR, and how should it be used?

The MR (Manual Reset) pin on the TPS3840DL25DBVR is an active-low input that forces RESET assertion when pulled ≤600mV. It features an internal 100kΩ pull-up, so it may be left unconnected for autonomous operation. When driven by a microcontroller GPIO, a ≥300ns low pulse initiates reset; release triggers deassertion only after VDD exceeds V_IT+ and the CT-programmed delay expires. This enables controlled system restarts during firmware updates or fault recovery.

Does the TPS3840DL25DBVR require a bypass capacitor on the VDD pin?

Yes, the TPS3840DL25DBVR requires a 0.1µF to 1µF ceramic bypass capacitor placed as close as possible between VDD (Pin 2) and GND (Pin 3). This stabilizes the internal bandgap reference and regulator during fast VDD transients, ensures reliable startup under noisy supply conditions (e.g., switching regulators), and prevents false resets caused by supply droop during MCU current surges. X7R dielectric is recommended for temperature stability.