Texas Instruments TPS3840DL35DBVR

Overview

TPS3840DL35DBVR from Texas Instruments is a nano-power, high-input-voltage supervisor IC with active-low open-drain reset output, 3.5V fixed threshold (±1.5% max), 300nA typical supply current, and programmable reset delay (50µs to 6.2s via external capacitor). It monitors VDD rails up to 10V in battery-powered safety-critical systems such as smoke detectors and smart meters.

For engineers reviewing the TPS3840DL35DBVR datasheet, TPS3840DL35DBVR pinout, TPS3840DL35DBVR application, or TPS3840DL35DBVR equivalent, key selection criteria include its 3.5V detection accuracy, SOT-23-5 package footprint, MR-initiated reset capability, and ultra-low quiescent current enabling multi-year operation on coin cells.

Technical Context

The TPS3840DL35DBVR implements a precision bandgap-based comparator with built-in hysteresis (100mV typical for 3.5V threshold) and glitch-immune input monitoring. Its internal CT pin circuitry provides a 500kΩ nominal resistance to ground, enabling predictable RC-based reset timing across temperature (–40°C to +125°C).

Reset assertion occurs when VDD falls below 3.5V or MR is pulled low; deassertion requires VDD to rise above 3.6V (3.5V + 100mV hysteresis) and expiration of the programmed tD delay. The open-drain RESET output supports flexible pull-up voltage levels up to 12V and exhibits 90nA leakage at 5.5V.

Key Specifications

Pinout & Package

SOT-23-5 (DBV) package: 2.90mm × 1.60mm footprint, 0.95mm 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 TPS3840PL35DBVR, the TPS3840DL35DBVR reduces component count via open-drain flexibility but requires a pull-up resistor; compared with MAX6326LT35D2T, it trades fixed timing for field-programmable delay and manual reset control at 23% lower quiescent current.

Availability

TPS3840DL35DBVR is available at Aetrix Electronics and suitable for smart metering, fire safety systems, and portable medical devices requiring stable component supply across extended product lifecycles.

Supply support for TPS3840DL35DBVR 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 specializing in analog, embedded processing, and power management technologies with over 90 years of innovation.

The TPS3840 family was designed for ultra-low-power voltage supervision in safety-critical battery-operated equipment, emphasizing nanoscale current consumption, wide input voltage range, and field-programmable timing.

FAQ

What is the exact threshold voltage and accuracy of the TPS3840DL35DBVR?

The TPS3840DL35DBVR has a fixed negative-going input threshold (V_IT−) of 3.5V 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 3.6V. This ensures robust detection of 3.3V rail brownouts while avoiding false triggers from noise.

How does the CT pin configure reset delay in the TPS3840DL35DBVR?

The CT pin on the TPS3840DL35DBVR connects to an external capacitor (0–10µF) to ground, forming an RC network with its internal 500kΩ resistance. With no capacitor, t_D is 50µs; with 10µF, t_D reaches 6.2s. Equation t_D = 618937 × C_{CT_EXT} + 50µs defines the relationship, validated across temperature.

Can the TPS3840DL35DBVR monitor a 9V battery directly without external components?

Yes - the TPS3840DL35DBVR supports 1.5V to 10V VDD operation, so it can directly supervise a 9V alkaline or lithium battery without resistive dividers. Its 3.5V threshold remains accurate across this range, and 300nA supply current minimizes battery drain during storage.

What is the function of the MR pin on the TPS3840DL35DBVR?

The MR pin on the TPS3840DL35DBVR is an active-low manual reset input. Pulling MR below 600mV (V_{MR_L}) asserts RESET regardless of VDD level. When released, RESET remains asserted until VDD exceeds 3.6V and the programmed t_D delay expires. MR is internally pulled up to VDD (100kΩ), so it may be left floating when unused.

Is the TPS3840DL35DBVR compatible with 1.8V microcontroller GPIOs for manual reset control?

Yes - the TPS3840DL35DBVR's MR pin accepts logic-low signals down to 600mV and logic-high up to 0.7×VDD. With VDD = 3.3V, V_{MR_H} = 2.31V, making it fully compatible with 1.8V GPIO outputs (which typically drive >2.0V for high). No level shifter is needed, simplifying interconnect.