Microchip Technology MIC2951-03BMM-TR

Overview

MIC2951-03BMM-TR from Micrel is a 5.0V, ±1% accuracy, 150mA low-dropout linear voltage regulator in an 8-pin MSOP package, featuring 250mV dropout at 100mA, reverse-battery protection (–20V), load-dump tolerance (+60V), and integrated error flag output - used in automotive power management, battery-powered instrumentation, and SMPS post-regulation.

For engineers reviewing the MIC2951-03BMM-TR datasheet, MIC2951-03BMM-TR pinout, MIC2951-03BMM-TR application, or MIC2951-03BMM-TR equivalent, key selection criteria include guaranteed 150mA output under –40°C to +125°C, programmable feedback architecture, open-collector ERR output for power-on reset, and MSOP thermal performance (θ_JA = 250°C/W).

Technical Context

The MIC2951-03BMM-TR implements a precision bandgap reference (1.235V ±1.5%) with internal error amplifier and PNP pass transistor, enabling stable regulation down to 40mV dropout at light loads. Its shutdown input (SHDN) accepts TTL-compatible logic control, while the ERR pin provides active-low open-collector fault signaling triggered by >5% output deviation.

It supports both fixed 5V operation (via SNS/TAP pins) and adjustable output (1.24V–29V) using external resistors on FB, with feedback bias current of 20–60nA and reference temperature coefficient of 50ppm/°C - ensuring tight stability across automotive temperature ranges.

Key Specifications

Pinout & Package

8-pin MSOP (MM8®) package with exposed thermal pad; θ_JA = 250°C/W, suitable for high-reliability automotive PCB layouts with limited copper area.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout voltage regulator applications.

Compared with LP2951ACN-3.3/NOPB and TPS76350DBVR, the MIC2951-03BMM-TR uniquely combines automotive-grade transient protection, integrated error flag, and MSOP packaging - making it the only option qualified for under-hood automotive use without supplemental protection circuitry.

Availability

MIC2951-03BMM-TR is available at Aetrix Electronics and suitable for automotive electronics, battery-powered instrumentation, and SMPS post-regulation requiring stable component supply across extended temperature and transient-voltage conditions.

Supply support for MIC2951-03BMM-TR 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

Micrel Inc. was a U.S.-based semiconductor company specializing in analog, power management, and timing solutions before its acquisition by Microchip Technology in 2015.

The MIC2951 series was designed specifically for automotive and industrial applications demanding robustness against reverse polarity, load dump, and wide-temperature operation - targeting systems where reliability outweighs cost sensitivity.

FAQ

What is the maximum input voltage the MIC2951-03BMM-TR can handle continuously?

The MIC2951-03BMM-TR supports a continuous input voltage range of +2.0V to +30V. While it survives +60V transients for ≤100ms (per ISO 7637-2), sustained operation above +30V risks permanent damage. The 30V limit applies across the full –40°C to +125°C junction temperature range and is specified in the Absolute Maximum Ratings table of the official Micrel datasheet.

Does the MIC2951-03BMM-TR require an external capacitor for stability, and what value is recommended?

Yes, the MIC2951-03BMM-TR requires a minimum 1.5µF output capacitor between OUT and GND for stability with 150mA loads. For loads below 10mA, 0.5µF suffices; for worst-case low-V_OUT (e.g., 1.23V) at 150mA, ≥5µF is required. Aluminum electrolytic or solid tantalum types with ESR ≤5Ω and resonant frequency >500kHz are recommended - ceramic capacitors alone are insufficient due to low ESR instability risk.

How does the ERR pin on the MIC2951-03BMM-TR function, and what external components are needed?

The ERR pin on the MIC2951-03BMM-TR is an open-collector output that pulls low (<400mV) when output voltage drops >5% below nominal (e.g., <4.75V for 5V mode). It requires an external pull-up resistor (100kΩ–1MΩ) to V_OUT or another supply. No resistor is needed if unused. The pin sinks up to 200µA and is commonly used for hardware power-on reset or MCU interrupt triggering in battery-monitoring circuits.

Can the MIC2951-03BMM-TR be configured for adjustable output voltages, and what is the supported range?

Yes, the MIC2951-03BMM-TR supports adjustable output from 1.24V to 29V using two external resistors on the FB pin. The internal 1.235V reference and 20–60nA feedback bias current allow precise programming; for best accuracy, R2 ≤100kΩ is recommended to minimize error from bias current. Fixed 5V operation is achieved by connecting OUT→SNS and FB→TAP - no external resistors needed.

What thermal derating applies to the MIC2951-03BMM-TR in its MSOP package?

The MIC2951-03BMM-TR in MSOP (MM8®) has a junction-to-ambient thermal resistance (θ_JA) of 250°C/W. At 150mA and 5V output with 12V input (7V drop), power dissipation is ~1.05W - resulting in ~262°C junction rise above ambient. Therefore, maximum ambient temperature must be limited to ≤–137°C to stay within 125°C T_J(max), which is impractical; real-world use requires PCB copper pour, thermal vias, or reduced load to maintain safe junction temperature.