Monolithic Power Systems Inc. MP1479GTF-Z

Overview

MP1479GTF-Z from Monolithic Power Systems is a fully integrated, synchronous step-down DC/DC converter with internal 140mΩ/60mΩ MOSFETs, delivering 1A continuous output current across a 4.2V–18V input range, operating at 800kHz fixed switching frequency, and supporting adjustable output voltages down to 0.8V - deployed in security cameras and digital set-top boxes for compact, high-efficiency local power regulation.

For engineers reviewing the MP1479GTF-Z datasheet, MP1479GTF-Z pinout, MP1479GTF-Z application, or MP1479GTF-Z equivalent, key selection criteria include COT control for fast transient response, thermal shutdown at 150°C, 190μA quiescent current, SOT563 package footprint constraints, and valley-current OCP with hiccup recovery.

Technical Context

The MP1479GTF-Z employs constant-on-time (COT) control architecture to maintain stable output voltage under dynamic load changes without external compensation, achieving sub-100ns minimum on-time and 180ns minimum off-time for wide VIN/VOUT ratios. Its integrated high-side and low-side N-channel MOSFETs enable synchronous rectification, eliminating external diode losses.

Internal bootstrap charging sustains gate drive for the high-side switch using a 1μF BST capacitor; EN pin logic enables direct system-level power sequencing with 1.2V rising threshold and 100mV hysteresis, while FB pin monitors output via resistor divider with 805mV reference and 10nA bias current.

Key Specifications

Pinout & Package

SOT563 package: ultra-compact 1.6mm × 1.6mm, 0.5mm pitch, thermally enhanced 6-pin surface-mount package with exposed pad (not electrically connected).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2451DT-LF-Z and TPS561201DRCT, the MP1479GTF-Z uniquely balances 1A capability, 800kHz frequency, SOT563 size, and COT control in a single package - making it optimal for cost-sensitive, space-constrained 12V-input consumer electronics where fast transient response and thermal resilience are mandatory.

Availability

MP1479GTF-Z is available at Aetrix Electronics and suitable for security cameras, digital set-top boxes, flat-panel monitors, and industrial HMIs requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for MP1479GTF-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, headquartered in Kirkland, WA, with global design and support centers.

The MP1479 belongs to MPS's MP14xx family of compact synchronous buck converters, designed specifically for cost-sensitive, space-constrained consumer and industrial applications demanding high efficiency, fast transient response, and minimal external components.

FAQ

What is the recommended input capacitor configuration for MP1479GTF-Z?

Use two parallel capacitors: a 22μF X5R/X7R ceramic placed within 1mm of VIN and GND pins, plus a 0.1μF high-frequency ceramic for high-frequency noise suppression. Total RMS current rating must exceed 0.5×IOUT (500mA), and voltage rating must be ≥20V to handle absolute maximum VIN transients.

Can MP1479GTF-Z operate with a pre-biased output?

Yes - the MP1479GTF-Z supports monotonic pre-bias start-up. During startup into a pre-charged output, the internal soft-start circuit and bootstrap refresh logic coordinate to prevent reverse current flow, ensuring the output voltage rises smoothly without undershoot or oscillation.

How does the valley-current OCP behave under sustained overload?

Under sustained overload, the MP1479GTF-Z enters hiccup mode: it disables switching, discharges the soft-start capacitor, waits ~10ms, then attempts restart. This cycle repeats until fault clears. Hiccup duty cycle is ~25%, limiting average power dissipation and preventing thermal damage during extended shorts.

What is the maximum allowable output capacitance for stable soft-start?

The maximum output capacitance is constrained by soft-start time and average start-up current. For 1.4ms soft-start and 1A load, Co_max ≈ 1.4mF assuming ILIM_AVG ≈ 1A. In practice, stay ≤220μF per rail when using standard 22μF ×2 configurations to ensure VOUT reaches regulation before SS completes.

Is the SOT563 package thermally adequate for 1A continuous operation at 12V input?

Yes - with proper PCB layout (2-layer board, 2-in² 2oz copper GND pour, 4+ thermal vias under exposed pad), θJA drops to ~55°C/W. At 1A/3.3V output, power dissipation is ~0.5W, resulting in ~30°C rise above ambient - well below the 125°C max junction temperature.

Does MP1479GTF-Z require an external bootstrap diode?

No - the MP1479GTF-Z integrates a bootstrap charging circuit with internal diode and regulator. Only a 1μF ceramic capacitor between BST and SW pins is required; adding an external diode degrades efficiency and violates the recommended layout.

How does FB pin voltage accuracy affect output regulation at light loads?

FB reference is trimmed to 805mV ±16mV over –40°C to +125°C. With 10nA bias current, a 100kΩ top resistor adds only 1mV error - maintaining ±1.5% total output accuracy even at 10mA load, critical for sensor biasing and ADC reference stability.