Texas Instruments TPS3840DL29DBVR

Overview

TPS3840DL29DBVR from Texas Instruments is a nano-power, high-input-voltage supervisor IC with active-low open-drain reset output, 2.9V fixed threshold (±1.5% max), 300nA typical supply current, and programmable reset delay up to 6.2s via external capacitor on CT pin. It monitors power rails in battery-backed industrial sensors and smart meters.

For engineers reviewing the TPS3840DL29DBVR datasheet, TPS3840DL29DBVR pinout, TPS3840DL29DBVR application, or TPS3840DL29DBVR equivalent, key selection criteria include its 1.5V–10V operating range, 220µs typical startup delay, built-in hysteresis (100mV typ. for V_IT− = 2.9V), MR input logic compatibility, and SOT-23-5 package footprint constraints.

Technical Context

The TPS3840DL29DBVR implements a precision bandgap-referenced comparator with internal hysteresis to detect V_DD falling below 2.9V (V_IT−) and rising above 3.0V (V_IT+). Its CT pin integrates a 500kΩ internal resistor to enable RC-based reset timing, while the MR input provides asynchronous reset assertion with 700ns propagation delay.

It features glitch immunity on both V_DD and MR inputs, with 10µs minimum pulse rejection at 5% overdrive, and operates across –40°C to +125°C. The open-drain RESET output requires an external pull-up and delivers ≤200mV low-level voltage at 2mA sink current.

Key Specifications

Pinout & Package

SOT-23-5 (DBV) package: 2.90mm × 1.60mm footprint, 0.95mm max height, gull-wing leads, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3840PL29DBVR, the TPS3840DL29DBVR saves board area by eliminating the pull-up resistor but requires careful impedance matching on the RESET line; versus MAX6326XR29T, it delivers 5.3× lower supply current and full delay programmability at identical threshold accuracy.

Availability

TPS3840DL29DBVR is available at Aetrix Electronics and suitable for grid infrastructure monitoring, factory automation sensors, and portable medical devices requiring stable component supply across extended temperature and long-life battery operation.

Supply support for TPS3840DL29DBVR 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 for industrial, automotive, and personal electronics markets.

The TPS3840 family was designed specifically for ultra-low-power, wide-input-voltage supervision in safety-critical industrial and energy infrastructure applications where long-term reliability and precise threshold accuracy are mandatory.

FAQ

What is the exact threshold voltage and accuracy of the TPS3840DL29DBVR?

The TPS3840DL29DBVR has a factory-trimmed negative-going input threshold (V_IT−) of 2.9V with ±1.5% maximum accuracy over –40°C to +125°C. Typical accuracy is ±1%, and hysteresis is 100mV (typical), resulting in a V_IT+ of 3.0V. This ensures robust detection of 3.3V rail collapse without false resets due to noise or slow transients.

How does the CT pin function in the TPS3840DL29DBVR?

The CT pin on the TPS3840DL29DBVR connects internally to a 500kΩ resistor and enables user-programmable reset delay. When a capacitor (0–10µF) is placed between CT and GND, the delay t_D follows t_D = 618937 × C_{CT_EXT} + 50µs. Leaving CT open yields the minimum 50µs delay. The TPS3840DL29DBVR uses this to replace discrete RC timers in system power sequencing.

Can the TPS3840DL29DBVR monitor a 9V battery directly?

Yes, the TPS3840DL29DBVR supports direct 9V battery monitoring because its V_DD input operates from 1.5V to 10V. With a 2.9V threshold, it reliably detects end-of-life voltage in 9V alkaline or lithium primary cells. No external resistive divider is needed, preserving nano-power operation and simplifying layout.

What is the role of the MR pin in the TPS3840DL29DBVR?

The MR pin on the TPS3840DL29DBVR provides asynchronous manual reset capability. Pulling MR low (≤600mV) for ≥300ns forces immediate RESET assertion, independent of V_DD level. When released, RESET remains asserted for the full programmed t_D delay before deassertion - enabling coordinated system resets triggered by host processors or front-panel buttons.

Is the TPS3840DL29DBVR compatible with 1.8V GPIO for manual reset control?

Yes, the TPS3840DL29DBVR MR pin accepts 1.8V logic levels: V_{MR_L} is guaranteed ≤600mV, and V_{MR_H} is ≥0.7×V_DD. At V_DD = 3.3V, V_{MR_H} ≥ 2.31V, so a 1.8V GPIO can safely drive MR low but must not be used to drive it high - instead, rely on the internal 100kΩ pull-up or an external weak pull-up to V_DD.