onsemi MC33565DMR2G

Overview

MC33565DMR2G from onsemi is a smart dual-input 3.3 V low-dropout voltage regulator with integrated low-voltage detector and external P-channel MOSFET switch drive, designed for glitch-free 5.0 V ↔ 3.3 V transitions in PCI/NIC peripheral cards. It delivers 200 mA regulated output, maintains ±2% output accuracy over −5°C to +150°C, features 4.02 V/4.17 V hysteresis thresholds, and prevents reverse current flow during sleep mode.

For engineers reviewing the MC33565DMR2G datasheet, pinout, applications, or equivalent options, key selection criteria include auxiliary-input quiescent current (1.9–3.0 mA), switch-drive rise/fall times (1.4 µs / 0.65 µs), sense-input regulation capability, thermal shutdown at ~170°C, and Pb-free Micro8 package compatibility with ACPI-compliant power management systems.

Technical Context

The MC33565DMR2G implements a dual-supply architecture where internal LDO regulation engages when main input (Pin 1) exceeds 4.02 V, while below that threshold it disables the LDO and asserts low-level gate drive (Pin 8) to enable an external P-channel MOSFET, sourcing 3.3 V directly from the auxiliary input (Pin 3). Its low-voltage detector uses precision resistive divider feedback with 150 mV hysteresis to ensure noise-immune mode switching.

Regulation relies on remote sense (Pin 6) connected directly to the load for tight line/load regulation (≤1.9 mV), while internal NPN pass device blocks reverse current (<25 µA at TJ = 25°C). External compensation requires ≥4.7 µF output capacitor with ESR ≤500 mΩ to maintain phase margin >60° across 0–200 mA load range.

Key Specifications

Pinout & Package

MC33565DMR2G is housed in a Pb-free Micro8 (MSOP-8) package (Case 846A), 3.0 mm × 3.0 mm × 1.0 mm, with exposed pad for thermal enhancement. Pin 1 is marked by dot; pins 2 and 5 are NC (no internal connection).

Key Features

Applications

Equivalent & Alternatives

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

Compared with NCP33565DMR2G, MC33565DMR2G offers identical performance but reflects updated onsemi branding and lifecycle management; versus TPS7A6033QDGKRQ1, it provides unique dual-input arbitration and external FET control essential for peripheral card power sequencing - a capability absent in single-rail alternatives.

Availability

MC33565DMR2G is available at Aetrix Electronics and suitable for PCI/NIC card design, industrial peripheral modules, and embedded carrier board development requiring stable component supply, Pb-free compliance, and guaranteed long-term manufacturability.

Supply support for MC33565DMR2G 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and IoT applications.

The MC33565DMR2G belongs to onsemi's Smart Power Management product line, engineered specifically for ACPI-compliant computer peripheral cards needing robust, glitch-free dual-rail voltage arbitration and seamless sleep/active transitions.

FAQ

What is the primary function of the MC33565DMR2G in a peripheral card design?

The MC33565DMR2G serves as a smart dual-input 3.3 V regulator that automatically switches between a 5.0 V main supply and a 3.3 V auxiliary supply to maintain uninterrupted power during ACPI sleep-to-active transitions. In the MC33565DMR2G, this is achieved via internal LDO regulation above 4.02 V and external P-MOSFET bypass below that threshold - ensuring zero-output-glitch behavior critical for PCI/NIC reliability.

Does the MC33565DMR2G require an external capacitor for stability, and what are the specifications?

Yes, the MC33565DMR2G requires an external output compensation capacitor of minimum 4.7 µF with ESR ≤500 mΩ for loop stability across temperature and load. This capacitor must be placed close to Pin 7 (Regulator Output) and Pin 6 (Sense Input); increasing capacitance improves load transient response. The MC33565DMR2G datasheet specifies these values as mandatory for maintaining ≥60° phase margin at full 200 mA load.

Can the MC33565DMR2G operate without connecting the Sense Input (Pin 6)?

No - the Sense Input (Pin 6) is required for correct MC33565DMR2G operation. It closes the feedback loop at the load to achieve tight line and load regulation (≤13.2 mV). Leaving Pin 6 unconnected degrades regulation accuracy and may cause instability or thermal shutdown under varying load conditions. The MC33565DMR2G functional block diagram and operating description explicitly mandate its use.

What is the maximum junction temperature before thermal shutdown activates in the MC33565DMR2G?

The MC33565DMR2G activates thermal shutdown at approximately 170°C junction temperature to protect against catastrophic failure. Unlike many regulators, it has no built-in hysteresis - so repeated cycling may occur if cooling is insufficient. The MC33565DMR2G's R_θJA is 172°C/W in Micro8 package; proper PCB copper area and airflow are essential to keep T_J below 150°C under 200 mA load.

Is the MC33565DMR2G pin-compatible with SOIC-8 versions like MC33565DR2G?

No - the MC33565DMR2G uses Micro8 (MSOP-8) packaging with different pin spacing (0.5 mm pitch) and footprint than SOIC-8 (1.27 mm pitch); although pin functions are identical, direct PCB replacement is not possible. The MC33565DMR2G requires dedicated layout for its 3.0 mm × 3.0 mm body and exposed thermal pad, unlike the larger SOIC-8 variants such as MC33565DR2G.