Texas Instruments LM810M3-4.00/NOPB

Overview

LM810M3-4.00/NOPB from Texas Instruments is a 3-pin SOT-23 active-high microprocessor reset supervisor IC designed to monitor 4.00 V supply rails in embedded digital systems. It asserts a high-level RESET signal during power-up, brown-out, and power-down events, with a guaranteed 140 ms minimum active timeout (240 ms typical) and valid output down to VCC ≥ 1 V. Its 15 µA typical supply current supports battery-powered industrial controllers.

For engineers reviewing the LM810M3-4.00/NOPB datasheet, LM810M3-4.00/NOPB pinout, LM810M3-4.00/NOPB application, or LM810M3-4.00/NOPB equivalent, key selection criteria include reset threshold accuracy (±3% at 4.00 V), temperature-stable operation (–40°C to 105°C), immunity to VCC transients (<20 µs for 100 mV overdrive), and compatibility with bidirectional µP reset pins via 4.7 kΩ series termination.

Technical Context

The LM810M3-4.00/NOPB implements a precision bandgap-based voltage comparator with factory-trimmed 4.00 V reset threshold and internal 240 ms timeout timer. Its active-high RESET output remains asserted while VCC falls below 4.00 V and for 240 ms after VCC rises above threshold, ensuring reliable microprocessor initialization across temperature.

It operates across full industrial temperature range (–40°C to 105°C) with 30 ppm/°C threshold drift, supports VCC from 1.0 V to 5.5 V, and maintains output validity even as supply collapses-enabling robust reset assertion during deep brown-out conditions without external pull-up.

Key Specifications

Pinout & Package

SOT-23 (DBZ) package, 2.92 mm × 1.30 mm body size, 3-pin surface-mount outline with GND–RESET–VCC pin order (top view).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX810LUR40+T, LM810M3-4.00/NOPB offers wider temperature range and lower supply current; versus TPS3808G33DBVR, it provides drop-in replacement simplicity and guaranteed 240 ms timing without external components-critical for space-constrained industrial controllers.

Availability

LM810M3-4.00/NOPB is available at Aetrix Electronics and suitable for factory automation, renewable energy inverters, and industrial HMI designs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LM810M3-4.00/NOPB 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 delivering analog and embedded processing solutions, with leadership in power management, signal chain, and microcontrollers.

The LM8xx family was engineered specifically for robust, low-cost microprocessor supervision in harsh industrial environments-emphasizing precision threshold accuracy, wide temperature operation, and transient immunity without external components.

FAQ

What is the exact reset threshold voltage for LM810M3-4.00/NOPB and how does it vary with temperature?

The LM810M3-4.00/NOPB has a factory-programmed reset threshold of 4.00 V with ±3% tolerance. At 25°C, it is specified as 3.93–4.06 V; over –40°C to 85°C, the range widens to 3.89–4.10 V; and at 85°C to 105°C, it extends to 3.80–4.20 V. Temperature coefficient is 30 ppm/°C, ensuring predictable drift across industrial operating conditions. This behavior is fully characterized in the LM810M3-4.00/NOPB datasheet Section 6.5.

Does LM810M3-4.00/NOPB require an external pull-up resistor on the RESET pin?

No-LM810M3-4.00/NOPB features a push-pull active-high output and does not require an external pull-up under normal operation (VCC ≥ 1 V). However, if VCC drops below 1 V and RESET validity must be maintained, TI recommends a 100 kΩ pull-up to VCC per Section 7.3.1.2 of the LM810M3-4.00/NOPB datasheet. This ensures defined logic state during deep brown-out.

What is the minimum VCC voltage at which LM810M3-4.00/NOPB guarantees valid RESET output?

LM810M3-4.00/NOPB ensures valid RESET output for VCC ≥ 1 V across the full temperature range. Below 1 V, output behavior is not guaranteed-though the device continues to monitor VCC. For applications requiring RESET assertion down to 0 V, a 100 kΩ pull-up to VCC is recommended. This specification is explicitly stated in Section 6.5 (Electrical Characteristics) of the LM810M3-4.00/NOPB datasheet.

Can LM810M3-4.00/NOPB interface directly with bidirectional microprocessor reset pins like those on the Motorola 68HC11?

Yes-LM810M3-4.00/NOPB can interface with bidirectional µP reset pins using a 4.7 kΩ series resistor between RESET and the µP pin, as shown in Figure 9 of the LM810M3-4.00/NOPB datasheet. This limits current conflict during µP-driven reset assertion while preserving LM810M3-4.00/NOPB's ability to drive the line high during power faults. No level-shifting is required.

What is the maximum VCC transient duration LM810M3-4.00/NOPB can reject without false triggering?

LM810M3-4.00/NOPB rejects negative-going VCC transients ≤20 µs in duration when the glitch magnitude is ≤100 mV below the 4.00 V threshold. This immunity is confirmed in Figure 8 (Maximum Transient Duration vs Reset Comparator Overdrive) of the LM810M3-4.00/NOPB datasheet. Adding a 0.1 µF bypass capacitor near the VCC pin further enhances noise rejection in electrically noisy industrial settings.