Texas Instruments TPS3840DL45DBVR

Overview

TPS3840DL45DBVR from Texas Instruments is a nano-power, high-input-voltage supervisor IC with active-low open-drain reset output, 4.5V fixed threshold (±1.5% max), 300nA typical supply current, and programmable reset delay up to 6.2s via external capacitor on CT pin - used for reliable power-on-reset and brownout detection in battery-powered industrial sensors.

For engineers reviewing the TPS3840DL45DBVR datasheet, TPS3840DL45DBVR pinout, TPS3840DL45DBVR application, or TPS3840DL45DBVR equivalent, this page delivers verified electrical specs, SOT-23-5 pin functions, real-world use cases in smart meters and fire safety systems, and two validated alternative supervisors with documented functional differences.

Technical Context

The TPS3840DL45DBVR implements a precision bandgap-based voltage comparator with built-in hysteresis (200mV typical for V_IT− = 4.5V) and glitch-immune input monitoring. Its internal CT pin circuitry provides a 500kΩ nominal resistance to ground, enabling accurate RC-based reset timing across –40°C to +125°C.

It features dual fault-detection paths: automatic assertion when V_DD drops below 4.5V (V_IT−) or manual assertion via MR pin pulled low (<600mV), with reset release delayed by t_D after V_DD rises above V_IT+ (4.7V) and MR returns high (>0.7×V_DD).

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3840DL45DBVR, the PL45 variant offers stronger output drive at the cost of 1.7× higher supply current, while the MAX6326UR45+T sacrifices flexibility (no MR/CT) for lower BOM count in static power-rail monitoring.

Availability

TPS3840DL45DBVR is available at Aetrix Electronics and suitable for smart metering, fire safety systems, and industrial field transmitters requiring stable component supply, long-lifecycle support, and guaranteed traceability for safety-critical designs.

Supply support for TPS3840DL45DBVR 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 decades of expertise in high-reliability industrial and automotive ICs.

The TPS3840 family was designed specifically for ultra-low-power, wide-input-voltage supervision in battery-backed and harsh-environment applications - delivering precision threshold accuracy, programmable timing, and robust fault immunity in minimal SOT-23-5 packaging.

FAQ

What is the exact threshold voltage and accuracy of the TPS3840DL45DBVR?

The TPS3840DL45DBVR has a factory-set negative-going input threshold (V_IT−) of 4.5V with ±1.5% maximum accuracy over –40°C to +125°C, and typical accuracy of ±1%. This value is laser-trimmed during production and does not require external calibration. The hysteresis is 200mV typical, resulting in V_IT+ = 4.7V.

How do I configure the reset delay time for the TPS3840DL45DBVR?

Connect an external capacitor between the CT pin (Pin 5) and GND. With no capacitor (CT floating), t_D = 50µs. A 100nF capacitor yields ~62ms; 1µF gives ~619ms; and 10µF achieves ~6.2s. The relationship follows t_D ≈ 618937 × C_CT + 50µs, where C_CT is in farads. Use X7R or C0G dielectrics for stability.

Can the TPS3840DL45DBVR monitor a 9V battery directly without external resistors?

Yes - the TPS3840DL45DBVR supports 1.5V to 10V V_DD, so it can directly monitor a 9V alkaline or lithium battery without any external voltage divider. Its 4.5V threshold triggers reset when battery voltage drops to 4.5V, providing ample headroom before complete discharge, and its 300nA I_DD minimizes load on the cell.

What is the function of the MR pin on the TPS3840DL45DBVR, and what voltage levels assert reset?

The MR pin is an active-low manual reset input. Pulling MR to ≤600mV (V_{MR_L}) for ≥300ns asserts RESET. When MR is left floating or pulled to ≥0.7×V_DD (V_{MR_H}), the device relies on V_DD monitoring. An internal 100kΩ pull-up ensures safe default operation if MR is unconnected.

Is the TPS3840DL45DBVR compatible with 1.8V logic systems?

Yes - the TPS3840DL45DBVR's open-drain RESET output is compatible with 1.8V systems when paired with a 1.8V pull-up resistor. Its MR pin accepts logic-low signals down to 600mV, and V_DD can operate as low as 1.5V, enabling integration into mixed-voltage domains. The RESET pin leakage is only 90nA at 5.5V, ensuring minimal impact on weak pull-ups.