Monolithic Power Systems Inc. MP9928GL-P

Overview

MP9928GL-P from Monolithic Power Systems is a high-voltage synchronous step-down controller IC designed for industrial and PoE power supply applications. It operates from 4V to 60V input, delivers up to 99.5% duty cycle, supports programmable 100–1000kHz switching frequency, integrates dual N-channel MOSFET drivers, and features precision 0.800V ±12mV feedback reference with cycle-by-cycle current limiting.

For engineers reviewing the MP9928GL-P datasheet, MP9928GL-P pinout, MP9928GL-P application, or MP9928GL-P equivalent, key selection considerations include its 60V max input rating, AAM/CCM mode selectability via CCM/AAM pin, 180° out-of-phase SYNCO output for multi-phase coordination, and dual independent current sense inputs (SENSE+/SENSE−) enabling accurate valley-current limiting in high-efficiency buck converters.

Technical Context

The MP9928GL-P implements a PWM current-mode control architecture with slope-compensated error amplifier output driving a comparator against sensed inductor current. Its internal oscillator supports resistor-programmed or external clock synchronization, and the 180° SYNCO output enables interleaved operation with a second MP9928 or compatible controller.

It features three configurable current limit thresholds (25mV/50mV/75mV) selected by ILIM pin state, integrated VCC1 LDO powered from VIN or external VCC2 (5–12V), and a floating high-side gate driver with bootstrap UVLO (3.05V rising threshold). The device enters hiccup-mode overcurrent protection when FB drops below 62.5% of reference, reducing thermal stress during sustained short-circuit conditions.

Key Specifications

Pinout & Package

MP9928GL-P is housed in a thermally enhanced QFN-20 package (3mm × 4mm, 0.5mm pitch) with exposed thermal pad. Pin numbering follows standard QFN top-view layout; pin 1 is marked by dot or notch orientation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous step-down controller applications.

Compared with LM5116PWPR and RT7297BZSP, MP9928GL-P uniquely combines dual-N-FET drive, selectable current limit thresholds, AAM/CCM mode flexibility, and 180° SYNCO - making it optimal for high-efficiency, multi-phase, or thermally constrained industrial buck converters.

Availability

MP9928GL-P is available at Aetrix Electronics and suitable for industrial control systems, Power-over-Ethernet (PoE) powered devices, and USB dedicated charging port (DCP) implementations requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP9928GL-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 mixed-signal ICs for power management, motion control, and automotive applications.

The MP9928 product line targets high-voltage DC-DC conversion in harsh environments - engineered for reliability across −40°C to +125°C, with emphasis on efficiency optimization, thermal resilience, and system-level integration in industrial and infrastructure power supplies.

FAQ

What is the minimum input voltage required for MP9928GL-P startup?

The MP9928GL-P requires ≥5V at the IN pin to initiate startup due to its 4.5–5.0V UVLO rising threshold. Once operational, it sustains regulation down to 4V input (UVLO falling threshold ~3.95V), supporting automotive cold-crank scenarios where battery voltage dips transiently.

How does the ILIM pin configure current limit thresholds?

The ILIM pin selects one of three fixed current sense voltage thresholds: connecting to GND sets 25mV, to VCC1 sets 50mV, and leaving floating sets 75mV. These correspond to peak inductor current limits scaled by external sense resistor value - e.g., 75mV across 10mΩ yields 7.5A peak current.

Can MP9928GL-P operate without an external bootstrap capacitor?

No. The TG (top gate) driver requires a bootstrap capacitor between BST and SW pins to generate the floating high-side gate drive voltage. Omitting this capacitor disables high-side switching, preventing normal buck operation. A 0.1µF X7R ceramic capacitor is recommended.

What is the purpose of the CCM/AAM pin?

The CCM/AAM pin configures operating mode: floating or tied to VCC1 enables continuous conduction mode (CCM); pulling low via resistor enables advanced asynchronous mode (AAM) for light-load efficiency optimization. AAM voltage must be ≥480mV to activate pulse-skipping behavior.

Does MP9928GL-P support external synchronization above 1MHz?

No. The EN/SYNC pin accepts external clock signals only within 100kHz–1000kHz, as specified in absolute maximum ratings and electrical characteristics. Attempting synchronization above 1MHz may cause erratic switching or failure to lock, and is outside guaranteed operating conditions.

How is power good (PG) functionality implemented?

The open-drain PG pin pulls low when output voltage falls outside ±10% of the nominal setpoint (e.g., 85–96.5% on rise, 81–92.5% on fall of V_FB). It features 25µs delay and self-driving capability - remaining functional even when MP9928GL-P is disabled, provided PG is externally pulled up to ≤5V.

What thermal derating applies to the QFN-20 package?

The QFN-20 (3mm×4mm) package has θ_JA = 48°C/W and θ_JC = 10°C/W on a 4-layer JEDEC PCB. At 25°C ambient, maximum continuous power dissipation is 2.6W. Derate linearly above 25°C: e.g., at 75°C ambient, max power drops to 1.3W to maintain T_J ≤ 125°C.