Monolithic Power Systems Inc. MP2235GJ-Z

Overview

MP2235GJ-Z from Monolithic Power Systems is a synchronous step-down DC/DC converter IC delivering 3A continuous output current with fixed 800kHz switching frequency, 4.5V–16V input range, and adjustable 0.8V–VIN×90% output voltage. It integrates 80mΩ high-side and 30mΩ low-side MOSFETs, supports external clock synchronization (300kHz–2MHz), and features power-save mode for light loads - deployed in notebook I/O power rails and flat-panel display bias supplies.

For engineers reviewing the MP2235GJ-Z datasheet, MP2235GJ-Z pinout, MP2235GJ-Z application, or MP2235GJ-Z equivalent, key selection criteria include verified thermal shutdown (150°C), OCP hiccup recovery, EN/SYNC dual-function pin behavior, and TSOT-23-8 package layout constraints for high-frequency SW/BST routing.

Technical Context

The MP2235GJ-Z employs peak-current-mode control with internal compensation, enabling fast transient response and stable loop operation without external type-III network components in most designs. Its integrated 5V VCC LDO powers control circuitry across the full VIN range and regulates BST via internal bootstrap charging with UVLO (2.2V rising threshold).

It implements Advanced Asynchronous Modulation (AAM) for PFM light-load operation below ~0.9A inductor peak current, while cycle-by-cycle over-current protection triggers hiccup mode when FB drops below 50% of reference during sustained overload or short-circuit conditions.

Key Specifications

Pinout & Package

MP2235GJ-Z 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). Pin pitch is 0.65mm; recommended footprint follows MPS AN-107 guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2235GJ-Z, MP2333GJ-Z delivers measurable improvements in light-load efficiency and input voltage margin, while TPS54331DR trades integration and advanced protection for broader input capability - making MP2235GJ-Z optimal only for cost-sensitive, volume-manufactured legacy designs requiring exact footprint compatibility.

Availability

MP2235GJ-Z is available at Aetrix Electronics and suitable for notebook I/O power, digital set-top box SoC core supplies, and flat-panel display bias circuits requiring stable component supply and long-term industrial availability.

Supply support for MP2235GJ-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, and global manufacturing partnerships.

The MP2235 belongs to MPS's mainstream synchronous buck converter product line, engineered for space-constrained, high-efficiency DC/DC conversion in consumer and computing applications where thermal performance and minimal external component count are critical.

FAQ

What is the maximum allowable input voltage for MP2235GJ-Z, and what happens beyond that?

The absolute maximum input voltage is 17V. Exceeding this rating risks permanent damage to the internal MOSFETs and control circuitry. The device includes under-voltage lockout (UVLO) that disables operation below 3.7V rising threshold, but no over-voltage protection - external TVS or clamp circuits are required for transient surges above 17V.

Can MP2235GJ-Z operate without an external soft-start capacitor?

No - the SS pin must be connected to a capacitor (minimum 1nF) to ground. Leaving SS open causes uncontrolled inrush current and potential output overshoot or input rail collapse. Typical values range from 4.7nF (0.34ms) to 47nF (3.4ms), selected based on system inrush limits and load capacitance.

How does the EN/SYNC pin function when used for external clock synchronization?

When a clean 300kHz–2MHz square wave is applied to EN/SYNC, the internal oscillator synchronizes to its rising edge after a 2ms stabilization delay. The pin retains enable functionality: logic-high (>1.4V) enables regulation; logic-low (<1.2V) forces shutdown regardless of clock presence.

Is the MP2235GJ-Z RoHS-compliant and lead-free?

Yes - all MP2235GJ-Z units are fully RoHS-compliant and lead-free, meeting Directive 2011/65/EU requirements. MPS confirms green status via its Quality Assurance portal, and the TSOT-23-8 package uses matte tin (Sn) lead finish with no exemption claims.

What is the minimum output voltage achievable with MP2235GJ-Z, and how is it set?

The minimum regulated output is 0.8V, set by the internal 0.807V feedback reference. It is configured using an external resistor divider from VOUT to GND, where R2 = R1 × 0.807V / (VOUT − 0.807V). For 0.8V output, R2 must be open-circuit (FB tied directly to VOUT), though practical designs use ≥1V to ensure stability.

Does MP2235GJ-Z require an external bootstrap diode, and when is it beneficial?

An external bootstrap diode (e.g., IN4148) from VCC to BST is optional but recommended when duty cycle exceeds 65% - such as in 12V-to-5V or 12V-to-3.3V conversions - to improve high-side gate drive strength and boost efficiency by ~1–2% under heavy load.

What thermal derating applies to the 3A output current specification?

The 3A rating is valid up to +85°C ambient on a standard 4-layer JEDEC PCB (2oz Cu, 100°C/W θJA). At +105°C ambient, output current must be reduced to ~2.2A to maintain TJ ≤125°C; full 3A requires active cooling or enhanced thermal pads per MPS AN-107 layout guidance.