Monolithic Power Systems Inc. MP4420HGJ-P

Overview

MP4420HGJ-P from Monolithic Power Systems is a synchronous step-down DC/DC converter IC with integrated 90mΩ/55mΩ MOSFETs, delivering 2A continuous output current across a 4V–36V input range and adjustable 0.8V–32.4V output. It operates at 410kHz (default), supports external synchronization up to 2.2MHz, and includes power-good signaling, thermal shutdown, and hiccup-mode over-current protection. Used in automotive cold-crank and industrial distributed power systems.

For engineers reviewing the MP4420HGJ-P datasheet, MP4420HGJ-P pinout, MP4420HGJ-P application, or MP4420HGJ-P equivalent, key selection criteria include its wide VIN range, internal MOSFET R_DS(ON), TSOT23-8 thermal performance (θ_JA = 100°C/W), soft-start timing (1.5ms typ), and PG threshold accuracy (±3.5% of V_FB).

Technical Context

The MP4420HGJ-P employs peak-current-mode control with an internal 0.8V reference and optimized compensation, enabling stable regulation without external loop components. Its current-mode architecture delivers fast transient response and inherent cycle-by-cycle over-current limiting.

It integrates a floating high-side gate driver powered by a bootstrap circuit with dedicated UVLO (2.2V rising), and features a programmable EN/SYNC pin that accepts 200kHz–2.2MHz external clocks for EMI reduction. The internal 5V VCC regulator tracks VIN down to 5V and powers all internal circuitry.

Key Specifications

Pinout & Package

MP4420HGJ-P is housed in a thermally enhanced TSOT23-8 package (2.9mm × 2.8mm × 1.0mm), optimized for high-power density and manual or automated assembly. Its exposed pad (not electrically connected) improves thermal dissipation on standard 4-layer PCBs (θ_JA = 100°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM61480RQWR and TPS54202HDDCR, the MP4420HGJ-P uniquely balances 2A capability, TSOT23-8 compactness, automotive-grade cold-crank support, and full-feature integration (PG, SYNC, hiccup OCP) - making it optimal for space- and reliability-constrained 12V/24V embedded systems.

Availability

MP4420HGJ-P is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC I/O modules, distributed telecom power supplies, and portable medical diagnostics requiring stable component supply across extended temperature and lifecycle demands.

Supply support for MP4420HGJ-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, and global manufacturing partnerships.

The MP4420H product line targets high-efficiency, wide-input DC/DC conversion for automotive, industrial, and telecom applications - emphasizing compact integration, robust protection, and ease of use in thermally constrained environments.

FAQ

What is the minimum input voltage required for MP4420HGJ-P to start switching?

The MP4420HGJ-P has an under-voltage lockout (UVLO) with a rising threshold of 3.5V. It begins switching only after VIN exceeds this level and EN is asserted high. Below 3.5V, the device remains fully disabled, drawing only 8μA shutdown current. This ensures reliable startup in automotive systems where battery voltage may dip during cranking.

Can MP4420HGJ-P operate with a 3.3V output and 36V input?

Yes - with a 36V input and 3.3V output, the MP4420HGJ-P achieves ~92% duty cycle, well within its 95% maximum limit. However, efficiency drops due to higher conduction loss and reduced thermal margin; ensure adequate PCB copper and airflow, and verify junction temperature stays below 125°C under full 2A load using θ_JA = 100°C/W.

How does the hiccup-mode over-current protection work?

Hiccup mode activates when output voltage collapses (FB < 84% of 0.792V) due to sustained overload or short circuit. The IC shuts down, waits ~30ms, then attempts restart. If fault persists, it repeats the cycle - limiting average short-circuit current to ~1A and preventing thermal damage. Recovery is automatic once load returns to safe levels.

Is an external bootstrap diode required for MP4420HGJ-P?

No - the MP4420HGJ-P uses an internal bootstrap charging circuit. An external diode (e.g., 1N4148) is optional and only beneficial at very high duty cycles (>65%) to improve efficiency by reducing BST capacitor charging losses. For most 12V→3.3V or 24V→5V applications, the internal circuit suffices.

What is the recommended layout practice for the FB pin?

The FB pin must be routed as a short, direct trace from the resistor divider's tap to the IC, shielded from SW and GND noise. Place the top feedback resistor (R1) and bottom resistor (R2) adjacent to the IC, with the FB connection landing directly on the R2–GND node. Avoid vias or long traces - even 2mm of added length can induce instability or ripple sensitivity.

Does MP4420HGJ-P support power-save mode at light loads?

Yes - it automatically enters power-save mode below ~200mA load, skipping switching cycles to maintain regulation while reducing quiescent current to ~0.5mA. This improves light-load efficiency (e.g., >85% at 10mA) without external control, ideal for always-on subsystems in automotive or IoT edge devices.

What is the maximum allowable RMS current for the input capacitor?

For worst-case conditions (VIN = 2×VOUT), the input capacitor RMS current equals half the output load current - so at 2A output, select a capacitor rated for ≥1A RMS. Ceramic capacitors (X5R/X7R) with 22µF total capacitance and 0.1µF high-frequency bypass meet this requirement while minimizing voltage ripple and EMI.