Texas Instruments LM3724IM5X-3.08

Overview

LM3724IM5X-3.08 from Texas Instruments is a precision 3.08 V active-low open-drain microprocessor reset supervisor IC in SOT-23-5 package, designed for reliable power-on, brown-out, and manual reset assertion in 3.3 V digital systems. It guarantees RESET validity down to VCC ≥ 1 V, delivers 100 ms minimum reset pulse width (190 ms typical), consumes only 7 µA typical supply current at 3.6 V, and operates across −40°C to +85°C.

For engineers reviewing the LM3724IM5X-3.08 datasheet, LM3724IM5X-3.08 pinout, LM3724IM5X-3.08 application, or LM3724IM5X-3.08 equivalent, this page provides verified functional identity, exact pin roles, temperature-stable reset threshold (3.08 V ±15 mV over −40°C to +85°C), open-drain output design implications, and validated alternatives for 3.3 V supply monitoring in portable and industrial embedded systems.

Technical Context

The LM3724IM5X-3.08 integrates a precision voltage reference (1.225 V), dual comparators (reset and manual reset), and a one-shot timer to generate a guaranteed 190 ms active-low reset pulse after VCC rises above 3.08 V or MR is deasserted. Its open-drain RESET output enables wired-OR configuration with other supervisors and level-shifting via external pull-up to voltages up to 5.5 V.

It features 30 ppm/°C reset threshold temperature coefficient, 100 ns MR glitch immunity, 22 kΩ internal MR pull-up, and full operation down to VCC = 1 V - enabling robust reset assertion during deep brown-out conditions without external support circuitry.

Key Specifications

Pinout & Package

SOT-23-5 (DBV) package: 2.9 mm × 1.6 mm × 1.1 mm body, gull-wing leads, RoHS-compliant green finish (Pb-free, no Sb/Br), MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor reset applications.

Compared with MAX811TEUS+T, LM3724IM5X-3.08 offers open-drain flexibility for system-level reset bus sharing; compared with TPS3808G30DBVR, it delivers proven 3.08 V threshold matching legacy designs and eliminates external timing components - reducing BOM count and qualification effort in cost-sensitive industrial applications.

Availability

LM3724IM5X-3.08 is available at Aetrix Electronics and suitable for industrial PLCs, portable medical devices, smart energy meters, and automotive body control modules requiring stable component supply, long-lifecycle assurance, and RoHS-compliant packaging.

Supply support for LM3724IM5X-3.08 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 connectivity technologies, with decades of expertise in power management and supervisory ICs.

The LM372x family was engineered specifically for high-reliability microprocessor reset supervision in cost-sensitive, battery-powered, and industrial embedded systems - prioritizing precision threshold stability, ultra-low quiescent current, and robust transient immunity.

FAQ

What is the exact reset threshold voltage of LM3724IM5X-3.08 and how stable is it over temperature?

The LM3724IM5X-3.08 has a factory-programmed reset threshold of 3.08 V with ±15 mV tolerance over the full industrial temperature range (−40°C to +85°C). Its temperature coefficient is specified at 30 ppm/°C, meaning threshold drift is limited to ±0.0093 V across the entire range - ensuring consistent 3.3 V supply monitoring without recalibration. This value is confirmed in the Electrical Characteristics table of the SNVS154E datasheet.

Does LM3724IM5X-3.08 require an external pull-up resistor on its RESET pin, and what value is recommended?

Yes, LM3724IM5X-3.08 requires an external pull-up resistor on its open-drain RESET pin because the output cannot drive high actively. A value between 10 kΩ and 100 kΩ is recommended depending on rise time and bus capacitance; 47 kΩ is commonly used for 3.3 V systems. The resistor connects from RESET to the target logic rail (e.g., 3.3 V or 5 V), enabling level translation and wired-OR capability - a key design feature explicitly documented for LM3724 in the Applications Information section.

Can LM3724IM5X-3.08 operate reliably when the supply voltage drops below 2.0 V?

Yes, LM3724IM5X-3.08 guarantees valid RESET output functionality down to VCC = 1.0 V, as stated in the Electrical Characteristics table and emphasized in the Circuit Information section. Below 1.0 V, the output may not sink rated current, but for VCC ≥ 1.0 V - including brown-out scenarios at 1.2 V or 1.5 V - the device asserts RESET correctly and maintains timing integrity. This is a defined specification, not a recommendation.

How does the manual reset (MR) input behave on LM3724IM5X-3.08, and what external components are needed?

The MR input on LM3724IM5X-3.08 is active-low with an internal 22 kΩ pull-up to VCC, so no external resistor is required. Pulling MR below 0.25×VCC for >10 µs initiates a 190 ms reset pulse. It accepts direct connection to logic outputs, microcontroller GPIOs, or momentary switches to ground. Glitches ≤100 ns are rejected - a hard specification confirmed in the Electrical Characteristics table under "MR Glitch Immunity".

Is LM3724IM5X-3.08 pin-compatible with other members of the LM372x family, such as LM3722 or LM3723?

Yes, LM3724IM5X-3.08 shares identical SOT-23-5 (DBV) pinout and footprint with LM3722 and LM3723, as shown in Figure 3 of the SNVS154E datasheet. Pin 1 = GND, Pin 2 = MR, Pin 3 = RESET, Pin 4 = GND, Pin 5 = VCC. However, output type differs: LM3722 uses active-low push-pull, LM3723 uses active-high push-pull, while LM3724IM5X-3.08 uses active-low open-drain - requiring circuit-level verification of RESET load and pull-up configuration during substitution.