Microchip Technology MIC4680-5.0BM-TR

Overview

MIC4680-5.0BM-TR from Micrel is a fixed-output 5.0V, 1.3A continuous current buck regulator in an 8-pin Power SOIC package, operating at 200kHz with 4V–34V input range and internal compensation. It integrates an NPN switch, thermal shutdown, cycle-by-cycle current limiting, and delivers up to 90% efficiency in high-efficiency step-down power conversion for industrial and embedded DC/DC applications.

For engineers reviewing the MIC4680-5.0BM-TR datasheet, MIC4680-5.0BM-TR pinout, MIC4680-5.0BM-TR application, or MIC4680-5.0BM-TR equivalent, key selection criteria include its fixed 5.0V ±1% output accuracy over load and temperature, 2µA shutdown current, 1.4V saturation voltage at 1A, and compatibility with standard surface-mount inductors and capacitors without external compensation.

Technical Context

The MIC4680-5.0BM-TR implements voltage-mode control using a 200kHz oscillator and a 1.23V bandgap reference, comparing feedback against the internal reference via an error amplifier to generate variable duty cycle. Its fixed 5.0V output version connects FB directly to VOUT, eliminating external resistors.

It features frequency foldback during short-circuit conditions (30–100kHz), thermal shutdown at 160°C, and TTL-compatible SHDN with 0.8V low-enable threshold and 1.6V high-disable threshold. The integrated NPN switch has 1.4V typical saturation voltage at 1A, enabling efficient operation across wide input ranges.

Key Specifications

Pinout & Package

Package: 8-pin Power SOIC (M) with exposed die-attach paddle connected to pins 5–8 (GND); θJA = 63°C/W on 1"² FR4 board; rated for –40°C to +125°C junction temperature.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar buck regulator applications.

Compared with LM2678-5.0/NOPB and TPS54202DR, the MIC4680-5.0BM-TR offers simpler implementation with no external compensation, lower shutdown current, and optimized thermal performance in Power SOIC-8-ideal for cost-sensitive, thermally constrained 1A applications where fixed 5V suffices.

Availability

MIC4680-5.0BM-TR is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and portable medical devices requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MIC4680-5.0BM-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 power management, analog, and timing solutions before its acquisition by Microchip Technology in 2015.

The MIC4680 family was designed as a high-current, easy-to-use buck regulator series targeting industrial and embedded applications needing fixed-output simplicity, robust thermal performance, and minimal external components.

FAQ

What is the output voltage tolerance of the MIC4680-5.0BM-TR over temperature and load?

The MIC4680-5.0BM-TR guarantees a 5.0V output with ±1% tolerance across –40°C to +125°C junction temperature and 0.1A to 1A load current, as verified in the Electrical Characteristics table under "MIC4680-5.0" conditions. This specification holds for input voltages between 8V and 34V, ensuring precision regulation in demanding environments where the MIC4680-5.0BM-TR operates.

Does the MIC4680-5.0BM-TR require external compensation components?

No, the MIC4680-5.0BM-TR features fully internal frequency compensation, enabling stable operation with only four external components: input capacitor, output capacitor, inductor, and Schottky diode. This eliminates the need for external RC networks or loop-tuning-confirmed in the General Description and Features sections of the datasheet. The MIC4680-5.0BM-TR is therefore ideal for rapid prototyping and production designs where layout simplicity and reliability are critical.

What is the maximum continuous output current of the MIC4680-5.0BM-TR, and what limits it?

The MIC4680-5.0BM-TR delivers up to 1.3A continuous output current, limited primarily by thermal dissipation. Its Power SOIC-8 package requires a minimum 6 cm² ground plane connected to pins 5–8 to maintain junction temperature below 125°C. At 1A and 12V input, typical efficiency is 79%, resulting in ~1.33W dissipation-verified in the Thermal Considerations section. Exceeding this without adequate copper area triggers thermal shutdown at 160°C, protecting the MIC4680-5.0BM-TR.

Can the MIC4680-5.0BM-TR operate from a 5V input source?

Yes, the MIC4680-5.0BM-TR supports input voltages as low as 4V, making it compatible with 5V sources. However, minimum input is defined as VOUT + 2.5V (i.e., 7.5V) for reliable regulation-so while 5V input will not damage the MIC4680-5.0BM-TR, it cannot sustain 5.0V output under load. For 5V-in/5V-out applications, consider LDOs or buck-boost topologies instead. This behavior is explicitly noted in Note 4 of the Absolute Maximum Ratings.

How does the shutdown function work on the MIC4680-5.0BM-TR?

The MIC4680-5.0BM-TR uses a TTL-compatible SHDN pin (Pin 1): applying ≤0.8V enables regulation, while ≥1.6V disables it, reducing quiescent current to 30µA typical. The pin exhibits hysteresis (≈0.8V turn-on, ≈1.6V turn-off) to prevent chatter near the threshold. When disabled, the internal NPN switch is off, SW node floats, and FB remains at 5V. This behavior is documented in the Pin Description and Shutdown Input Behavior sections of the MIC4680-5.0BM-TR datasheet.