Microchip Technology MIC3975-1.8BMM

Overview

MIC3975-1.8BMM from Microchip Technology is a 750 mA low-dropout linear regulator with fixed 1.8 V output, 350 mV dropout at full load, and ±2% output voltage accuracy over temperature and line/load conditions; used in FPGA core power, DSP I/O rails, and portable instrumentation where clean, stable low-voltage supply is critical.

For engineers reviewing the MIC3975-1.8BMM datasheet, MIC3975-1.8BMM pinout, MIC3975-1.8BMM application, or MIC3975-1.8BMM equivalent, key selection factors include guaranteed dropout performance at 750 mA, thermal shutdown with hysteresis, and integrated reverse-battery protection without external components.

Technical Context

The MIC3975-1.8BMM employs a PNP pass transistor architecture enabling ultra-low dropout and high PSRR (>70 dB at 1 kHz). It integrates internal current limiting, thermal foldback, and undervoltage lockout to prevent malfunction during brown-out conditions.

Designed for single-supply operation from 2.25 V to 16 V input, it delivers regulated 1.8 V output with <10 µA quiescent current in shutdown mode and supports ceramic or tantalum output capacitors ≥2.2 µF with ESR ≤1 Ω.

Key Specifications

Pinout & Package

Package: 8-pin MicroLeadFrame (MLF) 3 mm × 3 mm, exposed pad, RoHS-compliant, thermal resistance θ_JA = 45°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6219B182MR-G and NCP1117ST18T3G, the MIC3975-1.8BMM uniquely balances 750 mA capability, 350 mV dropout, and 3×3 mm MLF packaging-enabling compact, thermally efficient 1.8 V regulation where input headroom is limited and noise sensitivity is high.

Availability

MIC3975-1.8BMM is available at Aetrix Electronics and suitable for FPGA power management, DSP I/O conditioning, and portable medical instrumentation requiring stable component supply across extended production lifecycles.

Supply support for MIC3975-1.8BMM 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 company specializing in microcontrollers, analog devices, and power management ICs for industrial, automotive, and communications markets.

The MIC3975 family targets high-accuracy, low-noise LDO applications in space-constrained systems where input-to-output voltage differential is minimal and reliability under reverse-polarity stress is mandatory.

FAQ

What is the minimum input voltage required for MIC3975-1.8BMM to maintain regulation at full 750 mA load?

The MIC3975-1.8BMM requires a minimum input voltage of 2.15 V to sustain 1.8 V output at 750 mA, based on its 350 mV dropout specification. Below this, output voltage collapses linearly with input; design margin should include tolerance stack-up and transient droop.

Does MIC3975-1.8BMM require an external capacitor on the NR/ADJ pin?

No, the MIC3975-1.8BMM is a fixed-output variant; the NR/ADJ pin is internally connected to the reference and must remain unconnected. External components on this pin are unnecessary and may impair regulation stability.

Can MIC3975-1.8BMM operate with a 10 µF ceramic output capacitor?

Yes, the MIC3975-1.8BMM is stable with ceramic capacitors ≥2.2 µF and ESR ≤1 Ω. A 10 µF X7R MLCC meets both criteria and improves transient response and PSRR performance compared to minimum values.

How does the reverse-battery protection in MIC3975-1.8BMM function during field service?

The MIC3975-1.8BMM blocks reverse current and withstands −16 V applied to the IN pin without latch-up or damage. This protects downstream circuitry during incorrect battery insertion in portable instruments, eliminating need for external series diodes.

Is thermal pad soldering mandatory for MIC3975-1.8BMM in production assemblies?

Yes, the exposed thermal pad (EPAD) of the MIC3975-1.8BMM must be soldered to a solid PCB ground plane. Omitting this connection raises θ_JA beyond 45°C/W, risking thermal shutdown under 750 mA load and violating Microchip's validated thermal design guidelines.