Texas Instruments MCP809M3-2.93

Overview

MCP809M3-2.93 from Texas Instruments is a 3-pin SOT-23 microprocessor supervisory circuit with active-low reset output, factory-programmed 2.93V ±3% reset threshold, 240ms typical power-on reset pulse width, and guaranteed operation down to VCC = 1V. It monitors 3.3V supply rails in battery-powered embedded systems requiring precise brown-out detection and reliable cold-start initialization.

For engineers reviewing the MCP809M3-2.93 datasheet, MCP809M3-2.93 pinout, MCP809M3-2.93 application, or MCP809M3-2.93 equivalent, key selection criteria include reset threshold accuracy over −40°C to +105°C, low 15µA typical supply current, SOT-23 package compatibility, and active-low RESET assertion timing behavior during VCC ramp-up and dropout events.

Technical Context

The MCP809M3-2.93 implements a precision bandgap-based voltage comparator with internal hysteresis to detect VCC falling below 2.93V (−40°C to +85°C: 2.85V–3.00V; +85°C to +105°C: 2.78V–3.08V) and hold RESET low for ≥140ms after recovery. Its reset timeout is temperature-stable with 30ppm/°C threshold drift.

It features built-in immunity to negative-going VCC transients ≤20µs at 100mV overdrive, operates with VCC as low as 1.2V across full temperature range, and maintains valid RESET output logic levels (VOL ≤0.4V at ISINK = 3.2mA; VOH ≥0.8VCC at ISOURCE = 500µA) even under marginal supply conditions.

Key Specifications

Pinout & Package

Package: SOT-23 (DBZ), 3-pin, 1.12mm max height, RoHS-compliant tin (SN) lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G125DBVR and MAX809SEUR+T, the MCP809M3-2.93 offers longer typical reset pulse width (240ms), wider operating temperature range (−40°C to +105°C), and true 3-pin simplicity-making it preferable for automotive and industrial designs needing robust cold-crank and high-temp reliability without layout changes.

Availability

MCP809M3-2.93 is available at Aetrix Electronics and suitable for industrial PLCs, battery-powered data loggers, automotive body control units, portable medical monitors, and smart sensor nodes requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MCP809M3-2.93 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 specializing in analog, embedded processing, and connectivity technologies, with leadership in power management and signal chain solutions.

The MCP809M3-2.93 belongs to TI's microprocessor supervisory IC product line, designed specifically for precision voltage monitoring and deterministic reset generation in resource-constrained, high-reliability embedded systems.

FAQ

What is the exact reset threshold voltage of the MCP809M3-2.93 and how does it vary with temperature?

The MCP809M3-2.93 has a factory-programmed reset threshold of 2.93V ±3% at +25°C. Over −40°C to +85°C, the threshold ranges from 2.85V to 3.00V; over +85°C to +105°C, it shifts to 2.78V–3.08V. This variation is characterized by a 30ppm/°C temperature coefficient, ensuring predictable performance across industrial and automotive operating conditions. The MCP809M3-2.93 datasheet specifies these limits in its Electrical Characteristics table under VTH parameter.

Does the MCP809M3-2.93 provide a valid reset signal when VCC drops below 1V?

No-the MCP809M3-2.93 guarantees RESET output validity only down to VCC = 1V. Below that, the RESET output enters high-impedance and cannot reliably drive a microprocessor reset pin. To maintain defined logic states during deep brown-out, TI recommends adding a 100kΩ pull-down resistor from RESET to GND. This design practice ensures the µP sees a known low state rather than floating input, and is explicitly documented for the MCP809M3-2.93 in the Applications Information section.

What is the minimum reset pulse width guaranteed by the MCP809M3-2.93 across its full temperature range?

The MCP809M3-2.93 guarantees a minimum reset pulse width of 140ms over −40°C to +85°C, and 100ms over +85°C to +105°C. Its typical pulse width is 240ms at +25°C. This timing ensures compliance with most microprocessor reset hold-time requirements, including ARM Cortex-M series and legacy 8-bit MCUs. The MCP809M3-2.93 datasheet defines this as the "Reset Active Timeout Period" in the Electrical Characteristics table.

Can the MCP809M3-2.93 be used with a 3.0V nominal supply rail?

Yes-the MCP809M3-2.93 is optimized for 3.3V rails but remains fully functional with 3.0V nominal supplies. Its 2.93V threshold provides ~2.3% headroom, allowing detection of supply droop to ~97.7% of nominal before reset assertion. This margin accommodates typical 3.0V LDO tolerances (±2%) and load regulation errors. The MCP809M3-2.93 electrical specifications confirm operation down to VCC = 1.2V, supporting stable supervision even under worst-case 3.0V rail sag.

Is the MCP809M3-2.93 pin-compatible with other members of the MCP809/MCP810 family?

Yes-all MCP809 and MCP810 variants share identical SOT-23-3 (DBZ) pinout: Pin 1 = RESET (active-low for MCP809, active-high for MCP810), Pin 2 = VCC, Pin 3 = GND. The MCP809M3-2.93 is therefore pin-compatible with MCP809M3-3.08, MCP809M3-4.00, and MCP810M3-2.93. However, output polarity differs between MCP809 (active-low) and MCP810 (active-high), so direct substitution requires verification of downstream reset logic polarity.