Monolithic Power Systems Inc. MP44019GS-Z

Overview

MP44019GS-Z from Monolithic Power Systems is a CrM/DCM multi-mode active PFC controller in SOIC-8, delivering valley-switching control, dual OVP (OVP/OVP2), and <50mW no-load power loss. It regulates 400V boost output with 2.5V reference feedback, supports 85–265VAC input, and achieves <5% THD at full load for IEC 61000-3-2 Class C compliance in high-power AC/DC supplies.

For engineers reviewing the MP44019GS-Z datasheet, MP44019GS-Z pinout, MP44019GS-Z application, or MP44019GS-Z equivalent, key selection criteria include second OVP fault redundancy, mains-sense brown-in/brownout timing (50ms), COMP-based burst-mode thresholds (60mV/120mV), and ZCD/CS dual-function pin behavior for cycle-by-cycle OCL (500mV) and OCP (750mV).

Technical Context

The MP44019 operates in critical conduction mode (CrM) under heavy loads and transitions seamlessly to discontinuous conduction mode (DCM) at light loads using dead-time extension (tDEAD_MAX = 23.5µs) and internal COMP voltage tracking (VCOMPI_BOFF = 60mV, VCOMPI_BON = 120mV). Its valley-switching logic relies on ZCD/CS pin detection with 0.3µs leading-edge blanking and 150ns turn-on delay after zero-current crossing.

It implements dual over-voltage protection: primary OVP triggered at FB ≥ 2.7V (22µs blanking), and independent second OVP at OVP2 ≥ 2.7V (23µs blanking) with 0.1V hysteresis. Mains compensation uses MAINSIN pin with 1V brown-in and 0.9V brownout thresholds, enabling feed-forward line-voltage regulation and dynamic on-time adjustment (tON_LL = 24µs, tON_HL = 2.1µs).

Key Specifications

Pinout & Package

MP44019GS-Z is housed in an industry-standard SOIC-8 package (5.0mm × 6.0mm, 1.27mm pitch) with exposed pad optional per MPS design guidelines. Pin functions are validated per MP44019 Rev. 1.0 datasheet Figure 4 and Pin Functions table (p.4).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar CrM/DCM PFC controller applications.

Compared with UCC28056DR and FAN9612M, MP44019GS-Z uniquely delivers dual OVP hardware redundancy, sub-50mW standby loss via burst-mode control, and mains-compensated variable on-time DCM-making it the only option qualified for IEC 62368-1 Annex G and ENERGY STAR 8.0 high-power lighting/server applications.

Availability

MP44019GS-Z is available at Aetrix Electronics and suitable for LCD/OLED TV power supplies, server front-end PFC stages, and industrial open-frame SMPS requiring stable component supply, long lifecycle support, and RoHS-compliant sourcing.

Supply support for MP44019GS-Z 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-efficiency power management ICs, with over 20 years of expertise in PFC, DC/DC, and motor drivers.

The MP44019 belongs to MPS's CrM/DCM multi-mode PFC controller product line, designed specifically for high-power (>200W), low-standby-loss AC/DC conversion in consumer, computing, and industrial applications demanding IEC 61000-3-2 compliance.

FAQ

What is the purpose of the OVP2 pin, and how does it differ from the FB OVP function?

The OVP2 pin provides independent, hardware-redundant over-voltage protection for the 400V DC bus. Unlike FB-based OVP-which shares the same pin used for regulation and UVP-OVP2 accepts a separate voltage divider directly from the bus, triggering shutdown at 2.7V with 23µs blanking and 0.1V hysteresis. This meets IEC 62368-1 Annex G requirements for dual-fault tolerance, ensuring bus safety even if the FB divider fails open or short.

How does the MP44019 achieve <50mW no-load power loss?

MP44019 achieves ultra-low standby loss through three integrated mechanisms: (1) 0.25mA quiescent current in active mode, (2) burst-mode entry when internal COMP voltage drops below 60mV-shutting down most analog blocks, and (3) soft-off sequencing that disables gate drive before entering deep sleep. These features are validated at 230VAC input with 400V output and confirmed in Figure 9 and Table 1 of the datasheet.

Can the MP44019 operate without an auxiliary winding for ZCD sensing?

No-the ZCD/CS pin requires an auxiliary winding on the boost inductor to detect valley conditions. The winding ratio must satisfy Equation (3) in the datasheet: N ≤ (VOUT − √2 × VAC_MAX) / (2 × VZCD_H + VF). Without this winding, the controller defaults to fixed-frequency operation with degraded efficiency and increased THD; valley switching and DCM mode are disabled.

What is the significance of the nonlinear transconductance (GM) amplifier in dynamic response?

The nonlinear GM amplifier boosts error amplifier gain up to 8× during large output deviations: 4× gain increase for 4% undershoot (pulling COMP up faster) and 8× for 4% overshoot (pulling COMP down faster). This reduces output voltage dip during 0→240W load steps by 65% and prevents OVP triggering during transients-verified in Figure 3 and Load Transient waveforms on page 13.

How does the MAINSIN pin enable brown-in and brownout detection?

MAINSIN senses the peak rectified AC voltage via a resistor divider. When its voltage exceeds 1V (VMAINS_BI), the IC initiates COMP soft-start and begins switching (brown-in). If the voltage remains below 0.9V (VMAINS_BO) for 50ms (tBO), a brownout is confirmed and switching stops-COMP is pulled to 0V. Recovery occurs only after MAINSIN again exceeds 1V, ensuring clean restart after grid disturbances.

Is the SOIC-8 package thermally sufficient for 400W PFC designs?

Yes-the SOIC-8 package has θJA = 90°C/W on a 4-layer JEDEC PCB (JESD51-7). At 3mA operating current and 13V gate drive, total dissipation is <40mW. Even with worst-case 1.4W absolute max rating, junction temperature rise stays below 126°C at 25°C ambient-well within the 125°C max operating limit. Thermal derating is unnecessary for ≤400W designs with standard copper pour.