Monolithic Power Systems Inc. MP150GJ-P

Overview

MP150GJ-P from Monolithic Power Systems is a primary-side constant voltage (CV) regulator IC with integrated 500V/30Ω MOSFET, supporting Buck, Buck-boost, Boost, and Flyback topologies for offline AC/DC conversion. It delivers up to 2W output power, achieves <150mW no-load consumption, and operates in green-mode with frequency foldback and peak current compression. It targets low-power standby and auxiliary supplies in home appliances and white goods.

For engineers reviewing the MP150GJ-P datasheet, MP150GJ-P pinout, MP150GJ-P application, or MP150GJ-P equivalent, this page provides verified technical context, validated pin functions, topology-specific design meaning, and real-world protection behavior - all grounded in the official MP150 Rev. 1.15 datasheet and MPS application guidance.

Technical Context

The MP150GJ-P implements primary-side regulation using sampled output voltage via an internal error amplifier and ramp-compensated feedback comparator, eliminating optocoupler dependency. Its control loop monitors FB pin voltage against a 2.55V reference and adjusts switching duty cycle based on peak current limit (290mA typ) and minimum off-time (18µs).

It integrates a high-voltage start-up current source (3.5mA typ) tied to the DRAIN pin, enabling direct AC-line powering. Protection logic includes auto-restart thermal shutdown (150°C), VCC UVLO (5.3V turn-on / 5.6V turn-off), OLP (170ms timer at 37kHz), SCP (450mA threshold), and open-loop detection (60mV FB threshold).

Key Specifications

Pinout & Package

MP150GJ-P is packaged in TSOT23-5 - a thermally enhanced, surface-mount package with exposed drain pad for improved heat dissipation in compact offline converters.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar primary-side offline regulator applications.

Compared with MP150GJ-P, MP157GJ-Z offers higher power headroom and voltage rating but increases cost and footprint; LNK304DG-TL trades integration for compatibility with existing opto-based layouts but sacrifices light-load efficiency and BOM simplicity.

Availability

MP150GJ-P is available at Aetrix Electronics and suitable for home appliance auxiliary supplies, IoT device standby rails, and industrial control panel power management requiring stable component supply and long-lifecycle support.

Supply support for MP150GJ-P 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

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance analog and power ICs, with design centers in the US, China, and Taiwan.

The MP150 product line delivers highly integrated primary-side regulators targeting cost-sensitive, low-power offline AC/DC conversion in consumer and industrial applications where optocoupler elimination and green-mode efficiency are critical.

FAQ

What topologies does MP150GJ-P support, and which require isolation?

MP150GJ-P supports Buck, Buck-boost, Boost, and Flyback topologies. Only Flyback provides galvanic isolation; the others are non-isolated. Isolation is determined by transformer usage-not by the IC itself-so Flyback designs must include a properly rated transformer and Y-capacitor for safety compliance.

How does MP150GJ-P achieve optocoupler-free regulation?

It samples output voltage indirectly via a "sample-and-hold" capacitor charged through the freewheeling diode during MOSFET off-time. The FB pin reads this sampled voltage, comparing it to a 2.55V internal reference. This eliminates secondary-side feedback components while maintaining ±3% CV accuracy across line/load/temperature.

What is the role of the DRAIN pin beyond switching?

The DRAIN pin serves dual functions: (1) as the high-voltage drain terminal of the integrated 500V MOSFET, and (2) as the input to an internal high-voltage current source (3.5mA typ) that charges the VCC capacitor during startup and fault recovery-enabling self-powered operation without auxiliary winding.

Can MP150GJ-P operate from 230VAC and 115VAC inputs without redesign?

Yes. Its 500V MOSFET and wide VCC operating range (5.3V–5.6V) support universal input (85–265VAC). Designers must select appropriate input capacitor (e.g., 3µF/W for half-wave rectification) and verify minimum DC bus stays above 70V at 115VAC to prevent UVLO-induced dropout.

What is the significance of the 18µs minimum off-time specification?

The 18µs minimum off-time prevents sub-harmonic oscillation in continuous conduction mode (CCM) and ensures stable regulation at full load. During startup, it ramps down from 72µs to 18µs over 384 cycles-providing controlled inrush limiting and avoiding output overshoot into large capacitive loads.

How does MP150GJ-P handle short-circuit conditions?

When sensed peak current exceeds 450mA, MP150GJ-P immediately disables the MOSFET and enters auto-restart mode. The internal 16µA current source discharges the VCC capacitor until it reaches 2.4V, then re-enables the HV start-up source to recharge VCC-repeating the cycle until the fault clears.

Is MP150GJ-P RoHS-compliant and halogen-free?

Yes. MP150GJ-P is lead-free, halogen-free, and fully compliant with the EU RoHS directive. MPS confirms green status via its Quality Assurance portal, and the device carries no exemptions under Annex XIV of REACH.