Monolithic Power Systems Inc. MP2235GJ-P

Overview

MP2235GJ-P from Monolithic Power Systems is a synchronous step-down DC-DC converter with integrated 80mΩ/30mΩ MOSFETs, delivering up to 3A continuous output current across a 4.5V–16V input range, fixed 800kHz switching frequency, and adjustable 0.8V–VIN×90% output voltage - used in notebook I/O power rails and flat-panel display bias supplies.

For engineers reviewing the MP2235GJ-P datasheet, MP2235GJ-P pinout, MP2235GJ-P application, or MP2235GJ-P equivalent, key selection criteria include its TSOT-23-8 package thermal resistance (θJA = 100°C/W), cycle-by-cycle over-current protection with hiccup mode, AAM light-load power-save operation, and external clock synchronization capability from 300kHz to 2MHz.

Technical Context

The MP2235GJ-P employs peak-current-mode control with an internal 0.807V reference and integrated compensation network, enabling fast transient response and simplified loop stability. Its error amplifier drives a COMP node that directly modulates high-side MOSFET on-time based on sensed inductor current and FB voltage deviation.

It integrates a 5V LDO (VCC) powered from VIN, a bootstrap driver with 2.2V UVLO for the high-side gate, and EN/SYNC pin supporting both enable control and external clock synchronization - with internal 1MΩ pull-down and 6.5V Zener clamping for robust interface design.

Key Specifications

Pinout & Package

MP2235GJ-P is housed in an 8-pin TSOT-23 package (2.9mm × 1.6mm × 0.85mm), optimized for high-density PCB layouts with exposed thermal pad (GND-connected) for enhanced thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2333GJ-Z, MP2235GJ-P offers identical pinout and basic functionality but trades 2% peak efficiency and higher light-load IQ for proven field reliability in mature designs; versus TPS563201DSGR, it provides superior EMI control via SYNC and tighter FB reference tolerance (±1.5% vs. ±2%), at the cost of requiring external compensation components.

Availability

MP2235GJ-P is available at Aetrix Electronics and suitable for notebook I/O power, digital set-top box SoC core supplies, and flat-panel display bias applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP2235GJ-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 MP2235 belongs to MPS's high-frequency synchronous buck converter product line, engineered for space-constrained, efficiency-critical applications in computing, consumer, and industrial power systems where integration, thermal performance, and EMI control are primary design drivers.

FAQ

What is the maximum recommended PCB temperature rise for MP2235GJ-P under 3A continuous load?

At 3A continuous output with 12V input and 3.3V output, MP2235GJ-P typically exhibits a junction-to-ambient temperature rise of ~55°C on a standard 4-layer board with 1-in² 2-oz copper pour. To maintain TJ ≤ 125°C, ambient temperature should be limited to ≤70°C with adequate airflow or thermal vias beneath the GND pad.

Can MP2235GJ-P operate without an external bootstrap capacitor?

No - the BST pin requires a 0.1μF to 1μF ceramic capacitor connected between BST and SW pins to generate the floating voltage needed to drive the high-side MOSFET gate. Omitting this capacitor will prevent high-side switching and cause immediate functional failure.

Is the feedback reference voltage internally trimmed, and what is its drift over temperature?

Yes - the 0.807V reference is laser-trimmed during final test and specified from −40°C to +125°C with ±1.5% total accuracy (including initial tolerance and tempco). Typical drift is <30ppm/°C, resulting in <±12mV variation across the full operating range.

How does the MP2235GJ-P handle startup into a pre-biased output?

MP2235GJ-P does not support true pre-bias start-up. If VOUT is held above the regulated value before enable, the low-side MOSFET may conduct continuously during soft-start, causing reverse current flow and potential instability. External circuitry (e.g., ideal diode or hold-up capacitor) is required for pre-biased applications.

What is the minimum output capacitance required for stable operation?

Stable operation requires ≥22μF of effective output capacitance with ≤10mΩ ESR. Ceramic capacitors (X5R/X7R) are preferred; for 3.3V/3A operation, two parallel 10μF/0805 ceramics meet both capacitance and ripple current requirements while ensuring phase margin >45°.

Does MP2235GJ-P support forced PWM mode, or is it limited to AAM at light loads?

MP2235GJ-P operates exclusively in AAM (PFM) mode below ~0.9A load and automatically transitions to fixed-frequency PWM above that threshold. It does not offer a pin-selectable forced PWM mode - unlike some newer MPS parts such as MP2333, which adds MODE pin control.

What failure modes trigger hiccup mode, and how long is the restart interval?

Hiccup mode activates only after sustained over-current causes VFB to fall below ~400mV (50% of reference), indicating output short or severe overload. The device disables for ~30ms, then attempts restart; if fault persists, it repeats the cycle. This limits average power dissipation to <150mW during fault conditions.