Monolithic Power Systems Inc. MP2228GJ-Z

Overview

MP2228GJ-Z from Monolithic Power Systems is a high-frequency synchronous step-down DC/DC converter with integrated 100mΩ/40mΩ MOSFETs, delivering up to 2A continuous output current across a 6V–16V input range, fixed 800kHz switching frequency, and adjustable 0.8V–VIN×90% output voltage. It targets compact I/O power rails in notebook systems and flat-panel displays.

For engineers reviewing the MP2228GJ-Z datasheet, MP2228GJ-Z pinout, MP2228GJ-Z application, or MP2228GJ-Z equivalent, key selection criteria include its TSOT-23-8 package footprint, AAM-programmable light-load mode, thermal shutdown at 150°C, and feedback reference voltage of 807mV ±16mV.

Technical Context

The MP2228 operates in fixed-frequency peak-current-mode control with internal 5V LDO (VCC) powering gate drivers and analog circuitry. Its error amplifier compares FB voltage against an 807mV reference and drives COMP to regulate inductor current via cycle-by-cycle current limiting.

Bootstrap charging uses an external capacitor between SW and BST pins to sustain high-side driver operation; the floating driver includes UVLO (2.2V rising threshold). Under short-circuit conditions, frequency fold-back (25% of fSW when VFB < 400mV) and hiccup-mode OCP prevent thermal runaway.

Key Specifications

Pinout & Package

MP2228GJ-Z is housed in an 8-pin TSOT-23 package (JEDEC MO-193BA), with 0.65mm pitch, exposed thermal pad, and pin 1 identified by dot marking. The package supports high-density layout and moderate power dissipation (θJA = 100°C/W on 4-layer board).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2228GJ-Z, MP2238GJ-Z offers headroom for current growth while maintaining drop-in compatibility, whereas TPS562201DDCR trades AAM flexibility and thermal performance for lower unit cost and smaller footprint-making it suitable only for non-thermally constrained, fixed-load designs.

Availability

MP2228GJ-Z is available at Aetrix Electronics and suitable for notebook I/O power, digital set-top box SoC core supplies, and flat-panel monitor logic rails requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP2228GJ-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-performance analog and power ICs, with design centers in the US, China, and Taiwan.

The MP2228 belongs to MPS's high-efficiency synchronous buck converter product line, engineered for space-constrained consumer and computing applications demanding minimal external components and robust thermal behavior.

FAQ

What is the minimum recommended output capacitor value for stable operation?

The MP2228 requires ≥22μF ceramic output capacitance with low ESR for stable regulation and acceptable ripple. For 3.3V/2A operation, a 47μF X5R 0805 ceramic capacitor is typical; ESR should be ≤10mΩ to avoid loop instability. Layout proximity to FB and GND pins is critical-place capacitor within 3mm of FB and use dedicated ground vias.

Can the MP2228GJ-Z operate with an input voltage below 6V?

No. The MP2228GJ-Z has a guaranteed operating input range of 6V to 16V, with VIN UVLO rising threshold at 5.3V (typical). Operation below 6V is not characterized or supported; attempting to power it at 5V will result in erratic startup, failure to regulate, or thermal shutdown due to insufficient VCC regulation and weak gate drive.

How does the AAM pin affect efficiency versus load current?

At light loads (<300mA), pulling AAM low (e.g., 0.3V) forces discontinuous conduction mode (AAM), reducing switching losses and improving efficiency by ~3–5% versus CCM. At full load, AAM mode degrades efficiency due to increased RMS current; thus, AAM voltage must be tuned per application using the resistor divider network shown in Figure 4 of the datasheet.

Is an external bootstrap diode required for reliable operation?

An external bootstrap diode (e.g., 1N4148) is optional but recommended when duty cycle exceeds 65% (e.g., 12V→5V or 12V→3.3V), as it improves BST capacitor recharge efficiency and prevents driver dropout. Without it, BST voltage may sag under heavy load, causing high-side FET turn-off delay and increased conduction loss.

What is the maximum achievable output voltage accuracy over temperature?

Over –40°C to +125°C junction temperature, the FB reference voltage drifts ±10mV (±1.2%) around its 807mV nominal value. Combined with resistor divider tolerance (e.g., 1% R1/R2), total output voltage error remains within ±2.5% across full temperature and line/load conditions-sufficient for non-precision logic and interface supplies.

Does the MP2228GJ-Z support parallel operation for higher current?

No. The MP2228GJ-Z lacks current-sharing features such as current-monitor outputs, phase synchronization inputs, or master/slave configuration pins. Parallel operation is not supported and risks uneven current distribution, thermal imbalance, and potential device failure due to timing mismatch and circulating currents.

What PCB layout practices prevent noise coupling into the FB pin?

To prevent noise coupling, route the FB trace as a short, direct connection from the resistor divider tap to the FB pin-avoid vias, stubs, or proximity to SW/BST traces. Use a guard ring tied to GND around the FB trace and place R1/R2 within 2mm of the IC. Also, isolate the FB node from high-dv/dt nodes using ground pour gaps ≥0.5mm.