Monolithic Power Systems Inc. MP2303ADN-LF-Z

Overview

MP2303ADN-LF-Z from Monolithic Power Systems is a monolithic synchronous step-down DC/DC converter integrating 150mΩ high-side and 80mΩ low-side MOSFETs, delivering 3A continuous output current across 4.7V–28V input range with fixed 360kHz switching frequency and 0.80V feedback reference. It regulates down to 0.80V output voltage and supports notebook computers, distributed power systems, and pre-regulator applications.

For engineers reviewing the MP2303ADN-LF-Z datasheet, MP2303ADN-LF-Z pinout, MP2303ADN-LF-Z application, or MP2303ADN-LF-Z equivalent, key selection criteria include its integrated FETs, current-mode control architecture, programmable soft-start, cycle-by-cycle overcurrent protection, and thermal shutdown at 160°C - all critical for stable, compact buck designs in industrial and computing power rails.

Technical Context

The MP2303ADN-LF-Z employs current-mode control with an internal transconductance error amplifier (GEA = 550–1100 μA/V) and 360kHz oscillator (±10% over temperature), enabling fast transient response and inherent cycle-by-cycle current limiting. Its 0.80V ±2.5% feedback threshold and 1.2V internal reference support precise output regulation.

Operation requires a bootstrap capacitor between SW and BS pins to drive the high-side N-MOSFET gate above VIN; the IC integrates internal 5V rail charging for this function. Input under-voltage lockout (UVLO = 3.95V ±0.35V) and overvoltage protection (OVP = 0.95V ±0.05V at FB) provide robust fault handling without external circuitry.

Key Specifications

Pinout & Package

MP2303ADN-LF-Z is housed in an 8-pin SOIC-EP (SOIC8E) package with exposed thermal pad (Pin 4 connected to GND). The thermally enhanced layout supports 2.5W continuous power dissipation at +25°C ambient (θ_JA = 50°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2303ADN-LF-Z, MP2338DJ-LF-Z offers higher current capability and density but demands revised loop compensation and PCB layout, while LM2678SD-3.3/NOPB sacrifices integration and efficiency for legacy compatibility and lower unit cost.

Availability

MP2303ADN-LF-Z is available at Aetrix Electronics and suitable for notebook computers, distributed power systems, and industrial embedded controllers requiring stable component supply with full RoHS compliance and tape-and-reel packaging.

Supply support for MP2303ADN-LF-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 MP2300 series targets cost-sensitive, medium-power DC/DC conversion in computing, industrial, and consumer applications, emphasizing integration, thermal robustness, and ease of use in compact layouts.

FAQ

What is the maximum recommended output voltage for MP2303ADN-LF-Z?

The MP2303ADN-LF-Z supports output voltages up to 25V, set by the feedback resistor divider ratio and limited by the absolute maximum switch voltage rating of VIN + 0.3V. At 28V input, 25V output yields ~85% duty cycle, remaining within the 90% max duty spec. Higher outputs require verification of external component voltage ratings and thermal margin.

Can MP2303ADN-LF-Z operate with ceramic output capacitors only?

Yes - the MP2303ADN-LF-Z is explicitly designed for stability with low-ESR ceramic output capacitors (e.g., X5R/X7R 22–100μF). Its current-mode control and compensation architecture eliminate the need for tantalum or electrolytic caps, reducing size, cost, and aging-related drift in the output filter.

Is an external Schottky diode required for basic operation?

No - the MP2303ADN-LF-Z integrates both high-side and low-side MOSFETs, making an external Schottky diode optional. It may improve efficiency by ~1–2% at light loads or high duty cycles (e.g., 5V output from 12V input), but is not necessary for functional operation or stability.

How does the soft-start function interact with the EN pin?

The EN pin controls global on/off state, while the SS pin independently manages output voltage ramp rate after enable. When EN rises above 1.3V, the internal bias rails power up and the SS capacitor begins charging, initiating a controlled VOUT rise. If EN is toggled during soft-start, the SS capacitor discharges and restarts the ramp upon next enable.

What thermal considerations apply to the SOIC8E package?

The SOIC8E package features an exposed thermal pad (Pin 4) that must be soldered to a minimum 100mm² copper pour tied to internal/external GND planes. With proper layout, θ_JA is 50°C/W, allowing 2.5W dissipation at +25°C ambient. At 3A/12V→3.3V (75% efficiency), power dissipation is ~1.1W - well within safe operating limits.

Does MP2303ADN-LF-Z support output voltage sequencing?

No - MP2303ADN-LF-Z lacks dedicated tracking or sequencing pins. However, sequencing can be implemented externally using the EN pin: tie EN of downstream regulators to the MP2303ADN-LF-Z's output via a resistor divider or dedicated supervisor IC to enforce power-up order.

What is the purpose of the BS pin and how is it connected?

The BS (Bootstrap) pin supplies gate drive voltage to the high-side MOSFET. It must be connected to the SW node through a ≥0.01μF ceramic capacitor. During the low-side conduction phase, the capacitor charges from the internal 5V rail; during high-side conduction, it provides the boosted voltage needed to fully enhance the N-channel FET.