Texas Instruments TPS3840DL46DBVR

Overview

TPS3840DL46DBVR from Texas Instruments is a nano-power, high-input-voltage supervisor IC with active-low open-drain reset output, 4.6V fixed threshold voltage (V_IT−), ±1.5% threshold accuracy over −40°C to +125°C, 300nA typical supply current, and programmable reset delay up to 6.2s via external capacitor on CT pin. It monitors power rails in battery-powered safety-critical systems.

For engineers reviewing the TPS3840DL46DBVR datasheet, TPS3840DL46DBVR pinout, TPS3840DL46DBVR application, or TPS3840DL46DBVR equivalent, key selection criteria include its 4.6V detection threshold, SOT-23-5 package compatibility, open-drain output requiring pull-up, MR input for manual reset assertion, and ultra-low quiescent current enabling multi-year battery life in portable monitoring devices.

Technical Context

The TPS3840DL46DBVR implements a precision bandgap-based comparator with built-in hysteresis (200mV typical for V_IT− = 4.6V) and glitch immunity on both VDD and MR inputs. Its internal CT pin resistor (500kΩ typical) forms an RC timing network with external capacitor to generate user-programmable reset delays from 50µs to 6.2s.

It operates across 1.5V–10V supply range, supports fast startup delay (220µs typical), and features Power-On Reset (VPOR = 950mV) to prevent false resets during power ramp-up. The open-drain RESET output requires external pull-up and sinks up to 2mA while maintaining VOL ≤ 200mV.

Key Specifications

Pinout & Package

Package: SOT-23-5 (DBV), 2.90mm × 1.60mm footprint, surface-mount, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3840DL46DBVR, TPS3840DL49DBVR offers a higher trip point for tighter 5V rail margins, while MAX6375XR29+T sacrifices programmability and nano-power operation for simpler fixed-delay implementation-making TPS3840DL46DBVR optimal for battery-constrained, field-serviceable systems requiring flexible reset timing.

Availability

TPS3840DL46DBVR is available at Aetrix Electronics and suitable for fire safety sensor nodes, smart electricity meters, industrial PLC I/O modules, and portable medical diagnostic devices requiring stable component supply across extended temperature ranges and multi-year battery life.

Supply support for TPS3840DL46DBVR 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 voltage supervision in battery-backed and energy-harvesting systems, emphasizing nanoscale quiescent current, factory-trimmed accuracy, and flexible reset timing without external components.

FAQ

What is the exact threshold voltage of TPS3840DL46DBVR?

The TPS3840DL46DBVR has a factory-set negative-going input threshold voltage (V_IT−) of 4.6V, with ±1.5% accuracy over −40°C to +125°C. This value is laser-trimmed during production and does not require external resistors or calibration. The corresponding hysteresis (V_HYS) is 200mV typical, resulting in a release threshold (V_IT+) of 4.8V.

How do I configure the reset delay for TPS3840DL46DBVR?

To configure the reset delay for TPS3840DL46DBVR, connect an external capacitor between the CT pin (Pin 5) and GND. With no capacitor, t_D = 50µs. A 100nF capacitor yields ~62ms; 1µF yields ~619ms; and 10µF yields ~6.2s. The relationship follows t_D ≈ 618937 × C_{CT_EXT} + 50µs. Leaving CT floating achieves minimum delay.

Can TPS3840DL46DBVR monitor a 24V rail directly?

No, TPS3840DL46DBVR cannot monitor a 24V rail directly-the absolute maximum VDD rating is 12V. To supervise 24V, use a resistor divider to scale the voltage down to ≤10V at the VDD pin. Ensure the Thevenin equivalent resistance seen by VDD is ≤100kΩ to avoid accuracy degradation, and verify power dissipation in the divider resistors.

What is the function of the MR pin on TPS3840DL46DBVR?

The MR (Manual Reset) pin on TPS3840DL46DBVR is an active-low input that forces the RESET output low when pulled below V_{MR_L} (600mV max) for ≥300ns. It features an internal 100kΩ pull-up, so it may be left floating when unused. This allows microcontrollers or pushbuttons to initiate system reset independently of VDD conditions.

Does TPS3840DL46DBVR require an external pull-up resistor on the RESET pin?

Yes, TPS3840DL46DBVR uses an open-drain RESET output (Pin 1), which requires an external pull-up resistor to VDD or another logic rail. Typical values range from 10kΩ to 100kΩ. Without this resistor, the RESET signal cannot achieve a valid high state, compromising system reset sequencing and reliability.