Microchip Technology MIC39150-1.65BU

Overview

MIC39150-1.65BU from Microchip Technology is a 1.5 A low-dropout linear regulator (LDO) delivering a fixed 1.65 V output with 350 mV dropout at full load, ±1.5% initial accuracy, and integrated thermal shutdown and current limiting. It operates from 2.25 V to 16 V input and is used in FPGA core voltage regulation, low-voltage microcontroller power rails, and portable instrumentation.

For engineers reviewing the MIC39150-1.65BU datasheet, MIC39150-1.65BU pinout, MIC39150-1.65BU application, or MIC39150-1.65BU equivalent, key selection criteria include dropout voltage at 1.5 A, load regulation over temperature, PSRR at 1 kHz, thermal performance in SO-8EP, and compatibility with ceramic output capacitors ≥2.2 µF.

Technical Context

The MIC39150-1.65BU employs a PNP pass transistor architecture enabling stable operation with low-ESR ceramic capacitors and eliminating the need for external compensation. Its internal bandgap reference and error amplifier deliver tight line and load regulation across -40°C to +125°C junction temperature.

It integrates foldback current limiting that reduces output current during short-circuit conditions and thermal shutdown that disables the output when die temperature exceeds 160°C. No external components are required for basic operation beyond input and output capacitors.

Key Specifications

Pinout & Package

Supplied in an exposed-pad SO-8EP (Small Outline-8 with Exposed Pad) package, thermally optimized for PCB heat dissipation via the underside thermal pad soldered to a copper plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with the MIC39150-1.65BU, the XC6219B162MR-G offers smaller size but insufficient current capacity for FPGA or PLC use, while the NCP1117ST165T3G provides lower cost and wider availability but omits critical system-control features needed for autonomous thermal management and power sequencing.

Availability

MIC39150-1.65BU is available at Aetrix Electronics and suitable for FPGA core power, industrial PLC I/O modules, and portable test equipment requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MIC39150-1.65BU 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

Microchip Technology is a U.S.-based semiconductor manufacturer specializing in microcontrollers, analog devices, FPGAs, and power management ICs.

The MIC39xxx family delivers high-current, low-dropout regulators with integrated protection and system interface features for demanding embedded and industrial power applications.

FAQ

What is the maximum input voltage rating for the MIC39150-1.65BU?

The MIC39150-1.65BU supports an absolute maximum input voltage of 16 V. Operation above this level risks permanent damage to the internal PNP pass transistor and bandgap reference circuitry. For designs subject to transient overvoltage events exceeding 16 V, external clamping or upstream protection must be implemented before the MIC39150-1.65BU input pin.

Does the MIC39150-1.65BU require an external capacitor on the ADJ/SENSE pin?

No-the MIC39150-1.65BU is a fixed-output variant with the ADJ/SENSE pin internally tied to the output. This pin is not accessible for external feedback and does not require any external components. The device is designed for drop-in use with only IN, OUT, GND, ON/OFF, and THRM pins needing connection.

Can the MIC39150-1.65BU operate with a 2.2 µF ceramic output capacitor?

Yes-the MIC39150-1.65BU is explicitly characterized and stable with ceramic output capacitors as low as 2.2 µF and ESR < 100 mΩ. Unlike older LDOs, it does not require high-ESR tantalum or aluminum electrolytic capacitors, enabling smaller footprint, higher reliability, and improved transient response.

What thermal protection behavior does the MIC39150-1.65BU exhibit during overload?

Under sustained overload or elevated ambient temperature, the MIC39150-1.65BU activates thermal shutdown at approximately 160°C junction temperature, disabling the output. Once die temperature falls below ~140°C, the device automatically resumes regulation without requiring a reset pulse on the ON/OFF pin-enabling self-recovering fault tolerance in sealed enclosures.

Is the THRM pin of the MIC39150-1.65BU compatible with 3.3 V logic systems?

Yes-the THRM pin is an open-drain output rated for 6 V maximum, allowing direct interfacing with 3.3 V, 5 V, or even 12 V logic systems using an appropriate pull-up resistor. When asserted, it sinks current to indicate thermal fault; no level-shifting circuitry is required for integration into standard microcontroller GPIO monitoring circuits.