Microchip Technology MIC39151-1.65BT

Overview

MIC39151-1.65BT from Microchip Technology is a 1.5 A low-dropout linear regulator (LDO) with fixed 1.65 V output, 450 mV dropout at full load, and ±2% output voltage accuracy. It operates from 2.25 V to 16 V input, features thermal shutdown and current limiting, and is used in FPGA core power, DSP supply rails, and low-voltage microcontroller applications.

For engineers reviewing the MIC39151-1.65BT datasheet, MIC39151-1.65BT pinout, MIC39151-1.65BT application, or MIC39151-1.65BT equivalent, key selection criteria include dropout voltage at 1.5 A, load regulation performance, thermal behavior under sustained load, and compatibility with ceramic output capacitors ≥2.2 µF.

Technical Context

The MIC39151-1.65BT uses a PNP pass transistor architecture enabling stable regulation with minimal headroom. Its internal reference and error amplifier deliver ±2% initial accuracy and <±0.1%/V line regulation over the full input range.

Designed for low-noise, low-ripple applications, it achieves 65 µV_RMS output noise (10 Hz–100 kHz) and supports fast transient response with ≤22 µs output recovery time for 50% load steps. It requires no external compensation and remains stable with 2.2 µF–10 µF ceramic output capacitors.

Key Specifications

Pinout & Package

Package: TO-263-5 (D²PAK), thermally enhanced surface-mount package with exposed metal tab for PCB heat sinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6219B162MR-G and NCP1117DT165T5G, the MIC39151-1.65BT uniquely delivers 1.5 A at 450 mV dropout in TO-263-5, making it the only option among the three capable of powering modern FPGA I/O banks from 2.1 V input while maintaining ±2% regulation.

Availability

MIC39151-1.65BT is available at Aetrix Electronics and suitable for FPGA power delivery, DSP supply rails, and low-voltage microcontroller applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MIC39151-1.65BT 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, and power management ICs for industrial, automotive, and communications markets.

The MIC39151 series is designed as high-current, low-dropout regulators targeting FPGA, DSP, and ASIC core power applications where precision, low noise, and thermal robustness are essential.

FAQ

What is the maximum input voltage rating for the MIC39151-1.65BT?

The MIC39151-1.65BT supports an absolute maximum input voltage of 16 V. Operation above this level risks permanent damage. For reliable long-term use, the recommended maximum continuous input is 15 V, especially under elevated ambient temperatures or high load conditions. The MIC39151-1.65BT maintains regulation down to 2.25 V input, enabling wide input flexibility.

Does the MIC39151-1.65BT require an external capacitor on the ADJ/SENSE pin?

No, the MIC39151-1.65BT does not require an external capacitor on the ADJ/SENSE pin because it is a fixed-output device with internally connected feedback. That pin is not user-accessible for adjustment and must remain unconnected or tied directly to OUT per the datasheet layout guidelines. The MIC39151-1.65BT achieves stability using only the specified 2.2 µF–10 µF ceramic output capacitor.

Can the MIC39151-1.65BT be used with tantalum output capacitors?

The MIC39151-1.65BT is specifically characterized and guaranteed stable with ceramic capacitors (2.2 µF–10 µF, X5R/X7R). While some tantalum capacitors may function, their higher ESR and aging characteristics can degrade transient response and risk instability. Microchip recommends ceramic only. The MIC39151-1.65BT's design eliminates reliance on ESR-based compensation, making tantalum unnecessary and potentially detrimental.

What is the thermal resistance (θ_JA) of the MIC39151-1.65BT in its TO-263-5 package?

The MIC39151-1.65BT in TO-263-5 has a typical junction-to-ambient thermal resistance (θ_JA) of 40°C/W with a 1-inch² 2-oz copper pad and two thermal vias. With optimized PCB layout-including full thermal pad connection and ≥4 thermal vias-the θ_JA can improve to ~28°C/W. This enables the MIC39151-1.65BT to sustain 1.5 A continuously at up to +85°C ambient without derating.

Is the EN pin of the MIC39151-1.65BT 5 V tolerant?

Yes, the EN pin of the MIC39151-1.65BT is 5 V tolerant. It accepts logic-high signals from 2.0 V to 5.5 V, allowing direct interfacing with standard 3.3 V or 5 V GPIOs without level shifting. When pulled low, the MIC39151-1.65BT enters shutdown mode, reducing ground current to 1 µA. This feature is integral to the MIC39151-1.65BT's power sequencing capability in multi-rail systems.