Texas Instruments TPS3840DL18DBVR

Overview

TPS3840DL18DBVR from Texas Instruments is a nano-power, high-input-voltage supervisor IC with active-low open-drain reset output, 1.8 V fixed threshold (±1.5% max), 300 nA typical supply current, and programmable reset delay (50 µs to 6.2 s via external capacitor). It monitors power rails in battery-powered safety-critical systems such as smoke detectors and smart meters.

For engineers reviewing the TPS3840DL18DBVR datasheet, TPS3840DL18DBVR pinout, TPS3840DL18DBVR application, or TPS3840DL18DBVR equivalent, key selection criteria include its 1.5–10 V operating range, 100 mV typical hysteresis (for 1.6–3.0 V thresholds), 220 µs typical startup delay, SOT-23-5 package footprint, and MR input for manual system reset initiation.

Technical Context

The TPS3840DL18DBVR implements a precision bandgap-based voltage comparator with built-in hysteresis and glitch immunity on both VDD and MR inputs. Its internal CT pin connects to a 500 kΩ (typ) resistor enabling RC-based reset timing - no external timing IC required.

It operates across –40°C to +125°C with 1% typical VIT– accuracy and supports fast fault detection: propagation delay from VDD falling below threshold is 30 µs (max), while MR assertion triggers reset within 700 ns (max). The open-drain RESET output requires an external pull-up and sinks up to 2 mA at 200 mV VOL.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3840DL18DBVR, the PL18 variant reduces BOM count by integrating the pull-up function, while the MAX6326 offers proven reliability in legacy designs but sacrifices nano-power operation and configurability - making TPS3840DL18DBVR optimal for next-gen ultra-low-power systems requiring flexibility.

Availability

TPS3840DL18DBVR is available at Aetrix Electronics and suitable for smart metering, fire safety equipment, portable medical sensors, and industrial PLC modules requiring stable component supply across extended product lifecycles.

Supply support for TPS3840DL18DBVR 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-operated and energy-harvesting systems, emphasizing nanoscale quiescent current, wide input voltage tolerance, and field-programmable timing without microcontroller dependency.

FAQ

What is the exact threshold voltage and accuracy of TPS3840DL18DBVR?

The TPS3840DL18DBVR has a factory-set negative-going input threshold (VIT–) of 1.8 V with ±1.5% maximum accuracy over –40°C to +125°C. Typical accuracy is ±1%, and hysteresis is 100 mV (typical), ensuring robust immunity to noise-induced false resets near the trip point. This specification is verified per TI's SNVSB03E datasheet Section 6.5.

Does TPS3840DL18DBVR require an external pull-up resistor on the RESET pin?

Yes, TPS3840DL18DBVR features an open-drain active-low RESET output and requires an external pull-up resistor to VDD or another logic rail. Typical values range from 10 kΩ to 100 kΩ depending on rise time and bus loading requirements. The device itself does not integrate a pull-up, unlike the TPS3840PL18DBVR push-pull variant.

How is the reset delay programmed on TPS3840DL18DBVR?

The reset delay (tD) on TPS3840DL18DBVR is programmed by connecting an external capacitor between the CT pin (Pin 5) and GND. With no capacitor, tD = 50 µs (min); with 10 µF, tD ≈ 6.2 s (max). The relationship follows tD = 618937 × CCT_EXT + 50 µs, where CCT_EXT is in farads. A 100 nF capacitor yields ~62 ms delay.

Can TPS3840DL18DBVR monitor a 9 V battery directly?

Yes, TPS3840DL18DBVR supports 1.5 V to 10 V VDD input, allowing direct connection to 9 V alkaline or lithium batteries without external resistive dividers. Its wide range and nano-power consumption make it ideal for long-life 9 V–powered devices like smoke alarms and remote sensors.

What is the function of the MR pin on TPS3840DL18DBVR?

The MR (Manual Reset) pin on TPS3840DL18DBVR is an active-low input that forces the RESET output low when pulled below 600 mV (V_{MR_L}). It can be driven by a microcontroller GPIO or mechanical switch. When left floating, an internal 100 kΩ pull-up holds MR high, disabling manual reset. Pulse width must exceed 300 ns to trigger reliably.