Monolithic Power Systems Inc. MP3209DGU-LF-P

Overview

MP3209DGU-LF-P from Monolithic Power Systems is a current-mode 1.4MHz boost converter with integrated 0.5Ω MOSFET, supporting 2.5V–6V input and up to 22V output at 350mA peak switch current. It features internal soft-start, UVLO (2.45V turn-on), thermal shutdown (160°C), and operates in ultra-thin 2mm × 2mm 8-pin UTQFN. Used in OLED drivers and compact LCD displays where height <1mm is critical.

For engineers reviewing the MP3209DGU-LF-P datasheet, MP3209DGU-LF-P pinout, MP3209DGU-LF-P application, or MP3209DGU-LF-P equivalent, key selection factors include fixed 1.4MHz switching frequency, 1.25V feedback reference, 80% max duty cycle, thermal protection behavior, and package-specific thermal resistance (θJA = 80°C/W).

Technical Context

The MP3209DGU-LF-P implements fixed-frequency peak-current-mode control with an internal ramp compensation to suppress subharmonic oscillation above 50% duty cycle. Its error amplifier compares FB voltage against a 1.25V bandgap reference and drives PWM comparator via stabilized current-sense signal.

Operation relies on internal MOSFET switching between GND and up to 22V at SW pin, with EN-controlled startup and automatic soft-start ramping current limit over 120µs. Protection includes cycle-by-cycle current limiting (350mA typical), UVLO with 92mV hysteresis, and thermal shutdown at 160°C with automatic recovery.

Key Specifications

Pinout & Package

MP3209DGU-LF-P uses a 2 mm × 2 mm, 0.6 mm max height, 8-pin ultra-thin QFN (UTQFN) with exposed thermal pad. Pin 1 marked by top-side dot; pins 3 and 7 are NC (no connect).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar boost converter applications.

Compared with TPS610992DRCR and RT9013-33GJ5, MP3209DGU-LF-P uniquely combines 22 V output capability, integrated thermal protection, and 1.4 MHz operation in a 2 mm × 2 mm UTQFN - making it optimal for compact, high-voltage, battery-powered displays and modems requiring reliability under variable load.

Availability

MP3209DGU-LF-P is available at Aetrix Electronics and suitable for cell phones, OLED drivers, and external modems requiring stable component supply, RoHS-compliant packaging, and consistent lead-time performance across production volumes.

Supply support for MP3209DGU-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.

The MP3209 belongs to MPS's low-profile DC-DC boost converter product line, engineered specifically for space-constrained portable electronics needing efficient, high-voltage rail generation from single-cell batteries.

FAQ

What is the maximum recommended output voltage for MP3209DGU-LF-P?

The absolute maximum SW pin voltage is 25 V, but the device is characterized and specified for reliable operation up to 22 V output. Exceeding 22 V risks violating the 85% max duty cycle limit and may cause regulation loss or thermal stress under load. Designers should verify loop stability and inductor saturation margin when targeting outputs near 22 V.

Can MP3209DGU-LF-P operate with input voltage below 2.5 V?

No - the device incorporates under-voltage lockout (UVLO) with a 2.45 V turn-on threshold and 92 mV hysteresis. Below 2.25 V, the IC remains disabled. Attempting to force operation below 2.5 V will result in no switching activity and undefined behavior; it is not rated for sub-UVLO operation.

Is the exposed thermal pad on the UTQFN package electrically connected?

Yes - the exposed pad is internally connected to GND (pins 1 and 5). It must be soldered to a PCB thermal pad tied to the main ground plane to achieve the specified θJA = 80°C/W and ensure reliable thermal performance under 350 mA peak load conditions.

Does MP3209DGU-LF-P require external compensation components?

No - the error amplifier and PWM comparator are internally compensated. No external RC network is needed on the FB pin or elsewhere. This simplifies layout and eliminates tuning effort while maintaining stability across the full 2.5–6 V input and 3–22 V output ranges.

How does the EN pin behave during power-up?

The EN pin has a 1.3 V typical threshold with 100 mV hysteresis. When pulled high above 1.3 V, the device initiates soft-start after ~1 µs delay. If left floating, EN is indeterminate and may cause erratic startup; datasheet mandates tying unused EN to VIN for automatic enable or to GND for disable.

What is the purpose of the NC pins (3 and 7) in the UTQFN package?

Pins 3 and 7 are designated "No Connect" - they have no internal bond wire or silicon connection. They must remain unconnected on the PCB. Routing traces or applying solder paste to these pins violates the validated layout and may compromise thermal performance or EMI behavior.

Can MP3209DGU-LF-P drive a 350 mA continuous load?

No - the 350 mA rating is peak switch current, not continuous output current. Continuous output depends on input/output voltage ratio, efficiency, and thermal limits. At 5 V → 12 V conversion, typical continuous output is ~150 mA with 25°C ambient and proper thermal pad layout; higher loads require derating per θJA and ambient temperature.