Texas Instruments LM810M3X-4.38

Overview

LM810M3X-4.38 from Texas Instruments is a 3-pin SOT-23 microprocessor supervisory circuit with factory-programmed 4.38 V reset threshold, active-high RESET output, 240 ms typical reset timeout, 15 µA typical supply current, and operation over –40°C to +105°C. It monitors 5 V supply rails in embedded controllers and industrial microprocessor systems to ensure reliable power-on, brown-out, and power-down reset assertion.

For engineers reviewing the LM810M3X-4.38 datasheet, LM810M3X-4.38 pinout, LM810M3X-4.38 application, or LM810M3X-4.38 equivalent, key selection criteria include reset threshold accuracy (±3% at 25°C), guaranteed RESET validity down to VCC ≥ 1 V, immunity to VCC transients ≤ 20 µs, and compatibility with bidirectional µP reset pins via 4.7 kΩ series resistor.

Technical Context

The LM810M3X-4.38 implements a precision voltage comparator with internal bandgap reference to detect VCC falling below 4.38 V. Its active-high RESET output remains asserted for 240 ms after VCC rises above threshold, ensuring sufficient deassertion delay for microprocessor initialization sequences.

It operates across full industrial temperature range (–40°C to +105°C) with ±30 ppm/°C threshold temperature coefficient and maintains functional reset behavior even when VCC drops to 1 V - critical for low-voltage brown-out detection in battery-backed or energy-harvesting systems.

Key Specifications

Pinout & Package

LM810M3X-4.38 uses the standard 3-pin SOT-23 (DBZ) package, 2.92 mm × 1.30 mm body size, with gull-wing leads compatible with standard reflow profiles (MSL Level-1).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX810LUR43 and TPS3808G33DBVR, LM810M3X-4.38 provides optimal match for 5 V industrial systems needing fixed 4.38 V detection, guaranteed 240 ms timeout, and full –40°C to +105°C qualification - without design compromises on accuracy, temperature range, or footprint.

Availability

LM810M3X-4.38 is available at Aetrix Electronics and suitable for industrial PLCs, smart energy meters, factory automation controllers, and renewable energy inverters requiring stable component supply across long product lifecycles.

Supply support for LM810M3X-4.38 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets since 1930.

LM810M3X-4.38 belongs to TI's microprocessor supervisory IC product line, designed specifically for robust, low-power reset generation in harsh industrial environments where supply voltage stability cannot be assumed.

FAQ

What is the exact reset threshold voltage of LM810M3X-4.38 and how does it vary with temperature?

The LM810M3X-4.38 has a factory-programmed nominal reset threshold of 4.38 V, with ±3% tolerance at 25°C. Over the full operating range (–40°C to +105°C), the threshold varies by ±6%, corresponding to 4.16 V minimum and 4.56 V maximum. Its temperature coefficient is specified at 30 ppm/°C, ensuring predictable drift across thermal gradients encountered in industrial enclosures.

Does LM810M3X-4.38 provide a valid reset signal when VCC drops below 1 V?

No - LM810M3X-4.38 guarantees RESET output validity only down to VCC ≥ 1 V. Below 1 V, the internal circuitry ceases to function reliably. For applications requiring reset assertion all the way to 0 V, TI recommends adding a 100 kΩ pull-up resistor from RESET to VCC, as documented in the LM810 datasheet Section 7.3.1.2.

Can LM810M3X-4.38 interface directly with a microprocessor that has a bidirectional reset pin?

Yes, but requires a 4.7 kΩ series resistor between LM810M3X-4.38's RESET pin and the µP's bidirectional reset I/O, as shown in Figure 9 of the datasheet. This prevents contention when the µP drives its reset pin low while LM810M3X-4.38 is asserting high, ensuring clean reset signaling without latch-up risk.

What is the maximum VCC transient duration LM810M3X-4.38 can reject without generating a false reset?

LM810M3X-4.38 rejects negative-going VCC transients up to 20 µs in duration when the dip is 100 mV below the 4.38 V threshold. This immunity is validated per datasheet Figure 8 and enables reliable operation in electrically noisy environments such as motor drives or switch-mode power supplies without additional filtering.

Is LM810M3X-4.38 RoHS-compliant and what is its moisture sensitivity level?

Yes, LM810M3X-4.38 is RoHS-compliant (lead-free SN finish) and rated MSL Level-1 (unlimited floor life at ≤30°C/60% RH), per TI's packaging documentation. Its SOT-23 (DBZ) package is qualified for standard reflow profiles with peak temperature up to 260°C, making it compatible with automated PCB assembly processes.