Monolithic Power Systems Inc. MP2236GJ-Z

Overview

MP2236GJ-Z from Monolithic Power Systems is a high-frequency, synchronous step-down DC/DC converter delivering 6A continuous output current with 3V–18V input range and adjustable 0.6V–8V output. It integrates 25mΩ/12mΩ high- and low-side MOSFETs, uses constant-on-time (COT) control for fast transient response, and features hiccup-mode over-current protection and thermal shutdown. It powers core rails in flat-panel TV power supplies and digital set-top boxes.

For engineers reviewing the MP2236GJ-Z datasheet, MP2236GJ-Z pinout, MP2236GJ-Z application, or MP2236GJ-Z equivalent, key selection criteria include its TSOT23-8 package footprint, 600kHz switching frequency, 600mV reference voltage tolerance (±1mV at 25°C), COT stability without external compensation, and bootstrap capacitor requirement for high-side gate drive.

Technical Context

The MP2236GJ-Z implements constant-on-time (COT) control with internal ramp compensation to ensure loop stability across wide input/output conditions without requiring external compensation components. Its valley-current sensing OCP uses the low-side MOSFET's R_DS(ON) as the current-sense element, eliminating the need for a discrete sense resistor.

It supports pre-biased start-up and extends on-time during low-input-dropout operation to maintain regulation down to ~260kHz minimum frequency. The integrated floating high-side driver relies on a 0.1µF BST capacitor between SW and BST pins, with internal UVLO (1.2V rising, 150mV hysteresis) protecting the bootstrap supply.

Key Specifications

Pinout & Package

MP2236GJ-Z is housed in a thermally enhanced TSOT23-8 package (2.9mm × 1.6mm × 0.85mm), optimized for high-current density PCB layouts with exposed thermal pad (GND-connected). Pin 4 (GND) and Pin 1 (AGND) must be tied to the same ground plane using short, wide copper traces and multiple vias.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2236GJ-Z, MP2238GJ-Z offers headroom for current growth but sacrifices efficiency at nominal 6A load, while RT7297CGJ8 reduces bill-of-materials cost at the expense of robustness in fault conditions and thermal management.

Availability

MP2236GJ-Z is available at Aetrix Electronics and suitable for flat-panel television power supplies, digital set-top box core rails, and distributed monitor power systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP2236GJ-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 power management ICs, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MP2236 belongs to MPS's high-current, high-efficiency synchronous buck converter product line, engineered for space-constrained consumer and industrial applications demanding low quiescent current, fast transient response, and robust fault protection.

FAQ

What is the minimum recommended output capacitance for stable operation?

The MP2236GJ-Z is designed for ceramic-only output capacitors and remains stable with ≥22µF total capacitance (e.g., three 10µF X7R 0805s). Its internal ramp compensation eliminates ESR dependency, so low-ESR ceramics are mandatory - electrolytic or tantalum caps alone will cause instability and oscillation.

Can MP2236GJ-Z operate with an input voltage below 3V?

No. The absolute minimum operating input voltage is 3V per datasheet specifications. Below this, the internal bias circuitry cannot sustain regulation, and UVLO prevents startup. Input voltages down to 2.7V may trigger the UVLO rising threshold but are outside guaranteed operating conditions and not recommended for production designs.

Is an external bootstrap diode required for normal operation?

An external bootstrap diode (e.g., 1N4148) is optional and only beneficial when VIN < 5V, VOUT = 3.3V, and duty cycle exceeds 65%. Under standard 12V-to-3.3V operation, the internal bootstrap charging circuit maintains sufficient BST voltage without it - adding the diode provides negligible efficiency gain and increases BOM cost.

How does the hiccup-mode OCP behave during a sustained short circuit?

Under sustained short, MP2236GJ-Z enters hiccup mode after either three cycles (if UV2 threshold is crossed) or 31 cycles (if only UV1 is triggered), disabling switching for ~80ms before attempting restart at 12.5% duty cycle. This limits average short-circuit current to ~0.8A and junction temperature rise to <30°C, preventing thermal damage.

What is the maximum allowable PCB trace length between BST and SW pins?

The BST-to-SW trace must be ≤2mm in length and ≥0.3mm wide, with no vias or bends. Longer or narrower traces increase inductance, causing BST voltage droop during high-side turn-on and risking driver under-voltage lockout - resulting in erratic switching or complete failure to regulate.

Does MP2236GJ-Z support forced PWM mode at light loads?

No. MP2236GJ-Z operates exclusively in automatic PFM/PWM transition mode - it cannot be forced into continuous PWM at light loads. At I_OUT < 100mA, it enters skip-mode PFM to maintain >85% efficiency; disabling PFM would require external circuitry and is not supported by the IC's architecture.