Monolithic Power Systems Inc. MP44011HS-LF-P

Overview

MP44011HS-LF-P from Monolithic Power Systems is a boundary-conduction-mode (BCM) active power-factor correction (PFC) controller with integrated harmonic injection, designed for pre-regulation in two-stage AC/DC converters. It delivers precise output voltage regulation (2.5 V ±15 mV), supports 13.4–22 V supply operation, features ultra-low 40 µA start-up current and 0.65 mA quiescent current, and targets LED lighting drivers where reduced bus capacitance and smaller transformer size are critical.

For engineers reviewing the MP44011HS-LF-P datasheet, MP44011HS-LF-P pinout, MP44011HS-LF-P application, or MP44011HS-LF-P equivalent, key selection criteria include harmonic-injection capability for THD reduction, ZCS-triggered MOSFET turn-on timing, internal 1.72 V current-sense clamp, adjustable OVP via COMP pin current sensing (40 µA dynamic trigger), and SOIC-8 package compatibility with standard PCB layout practices.

Technical Context

The MP44011HS-LF-P implements boundary-conduction-mode control using zero-current sensing (ZCS) on Pin 5 to initiate MOSFET turn-on at inductor current zero-crossing, with internal hysteresis (2.1 V rising / 1.35 V falling thresholds) and clamps (7.8 V high / 0.55 V low). Its harmonic injection function modifies the multiplier output (Pin 3) by adding constant-ratio harmonics to the rectified line voltage reference, generating a "choppy sinusoidal" current envelope that reduces peak primary current and enables smaller magnetics.

It integrates a precision error amplifier (FB pin reference = 2.50 V ±15 mV, 80 dB open-loop gain, 1 MHz GBW) and dual over-voltage protection: static OVP triggers when COMP falls below 2.2 V, while dynamic OVP monitors COMP pin current (35–40 µA threshold) to respond to abrupt output voltage surges-both disabling the gate driver (Pin 7) to halt switching.

Key Specifications

Pinout & Package

MP44011HS-LF-P is housed in an 8-pin SOIC package (JEDEC MS-012, variation AA) with standard 1.27 mm pitch, 3.9 mm width, and 4.9 mm length. Thermal resistance θ_JA = 90°C/W enables operation up to +125°C junction temperature with minimal heatsinking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar boundary-mode PFC controller applications.

Compared with MP44010HS-LF-P, MP44011HS-LF-P delivers measurable THD reduction and component downsizing in LED lighting; versus UCC28051DR, it offers lower system cost and simpler layout for sub-50 W BCM designs but lacks CCM flexibility and advanced protection features.

Availability

MP44011HS-LF-P is available at Aetrix Electronics and suitable for LED lighting drivers, two-stage AC/DC converters, compact boost PFC modules, and low-standby-power adapters requiring stable component supply, RoHS-compliant packaging, and long-term industrial availability.

Supply support for MP44011HS-LF-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, and global manufacturing partnerships.

The MP44011 belongs to MPS's boundary-mode PFC controller product line, engineered specifically to simplify active power factor correction in cost-sensitive, space-constrained LED lighting and consumer power supplies.

FAQ

What is the purpose of the harmonic injection function in MP44011HS-LF-P?

The harmonic injection function modifies the multiplier output (Pin 3) by adding constant-ratio harmonics to the rectified AC line voltage reference. This shapes the current-sense threshold into a "choppy sinusoid," reducing peak primary current in flyback PFC topologies. As a result, transformer core size and bus capacitor value can be reduced-demonstrated in the datasheet design example as enabling an EE25 core and 47 µF capacitor instead of larger alternatives.

How does MP44011HS-LF-P implement zero-current switching, and what are the ZCS pin thresholds?

MP44011HS-LF-P detects inductor current zero-crossing via the ZCS pin (Pin 5), which monitors voltage from an auxiliary winding. It triggers MOSFET turn-on on the falling edge of that signal. The ZCS comparator has a rising threshold of 2.1 V and falling threshold of 1.35 V, with hysteresis of 0.75 V. Internal clamps limit ZCS voltage to 7.8 V (high) and 0.55 V (low) to protect against transients.

Can MP44011HS-LF-P be used in continuous conduction mode (CCM) PFC applications?

No-MP44011HS-LF-P is strictly a boundary-conduction-mode (BCM) controller. Its architecture relies on zero-current sensing (ZCS) to initiate each switching cycle and does not support fixed-frequency or average-current-mode control required for CCM operation. For CCM PFC, MPS recommends the MP44015 or industry alternatives like the UCC28070.

What is the role of the COMP pin beyond error amplifier output?

In addition to driving the compensation network between COMP and FB pins, the COMP pin serves as the sensing node for dynamic over-voltage protection (OVP). When output voltage surges, current flows into COMP due to the mismatch between FB reference and actual output. At 40 µA, the dynamic OVP activates, blocking the gate driver. This dual-use eliminates external OVP circuitry while maintaining fast response (<1 µs propagation delay).

How does the MP44011HS-LF-P achieve ultra-low start-up current?

MP44011HS-LF-P achieves ≤40 µA start-up current through a dedicated low-power startup circuit that draws current only from VIN during initial power-up. Once the internal regulator reaches regulation, the main bias circuit engages and the startup path is disabled. This design avoids large startup resistors or auxiliary windings, enabling reliable cold-start from minimal energy sources such as small capacitive droppers.

Is the SOIC-8 package of MP44011HS-LF-P thermally adequate for 30 W LED driver applications?

Yes-the SOIC-8 package has θ_JA = 90°C/W on a standard 4-layer PCB (JESD51-7). At 30 W output with typical 85% efficiency, dissipation is ~5.3 W. With 25°C ambient, junction temperature rises to ~25 + (5.3 × 90) ≈ 502°C-exceeding rating. However, actual IC power dissipation is <0.5 W (quiescent + gate drive losses), yielding T_J ≈ 25 + (0.5 × 90) = 70°C, well within the –40°C to +125°C operating range.

Does MP44011HS-LF-P support programmable frequency or soft-start?

No-MP44011HS-LF-P operates at variable frequency determined by line voltage, inductance, and load (typical 40–120 kHz range). It lacks external frequency programming pins or soft-start circuitry. Startup is controlled by UVLO hysteresis (11–13.4 V turn-on), and the internal starter ensures reliable initial switching even without ZCS signal, with re-start time of 80–280 µs after disable.