Monolithic Power Systems Inc. MP2348GTL-Z

Overview

MP2348GTL-Z from Monolithic Power Systems is a synchronous step-down DC/DC converter with integrated 75mΩ/40mΩ MOSFETs, delivering up to 4A continuous output current across a 4.2V–24V input range. It operates at 650kHz fixed switching frequency with Constant-On-Time (COT) control, supports forced PWM, PFM, and ultrasonic modes, and features thermal shutdown, OCP, SCP, and pre-biased start-up-used in flat-panel displays for stable 3.3V/4A local power rails.

For engineers reviewing the MP2348GTL-Z datasheet, MP2348GTL-Z pinout, MP2348GTL-Z application, or MP2348GTL-Z equivalent, key selection criteria include input voltage range compatibility, SOT583 package layout constraints, MODE pin configuration for light-load efficiency tuning, and FB resistor divider design for precise output voltage setting.

Technical Context

The MP2348GTL-Z employs a constant-on-time (COT) control architecture with internal high-side and low-side N-channel MOSFETs, enabling fast transient response without external compensation. Its valley-current sensing enables over-current protection with hiccup-mode recovery, while bootstrap charging sustains gate drive for the high-side switch across the full input range.

Three operating modes-forced PWM, PFM with ultrasonic mode (USM), and PFM without USM-are selected via the MODE pin using open-drain, grounded, or resistor-to-GND configurations. Soft-start is externally programmable via capacitor on SS pin, and feedback uses a precision 802mV reference with <50nA bias current for tight regulation.

Key Specifications

Pinout & Package

SOT583 (1.6mm × 2.1mm) thermally enhanced 8-pin package with exposed pad for improved PCB heat dissipation and compact footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2348GTL-Z, MP2338GTL-Z reduces output capability but maintains identical feature set and footprint for cost-sensitive 3A designs, while TPS54340DDAR trades integration for extended input range and design flexibility at the expense of layout complexity and component count.

Availability

MP2348GTL-Z is available at Aetrix Electronics and suitable for flat-panel televisions, game consoles, digital set-top boxes, and industrial HMIs requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP2348GTL-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 over two decades of innovation in DC/DC converters, LED drivers, and motor drivers.

The MP2348 belongs to MPS's high-efficiency synchronous buck converter product line, designed specifically for space-constrained consumer and industrial applications demanding high current density, low quiescent power, and robust protection in miniature packages.

FAQ

What is the minimum recommended BST capacitor value for MP2348GTL-Z?

A 1µF X5R/X7R ceramic capacitor rated ≥10V is required between BST and SW pins. This value ensures sufficient charge storage to maintain high-side gate drive during maximum duty cycle operation, especially at low input voltages (e.g., 4.2V). Lower values risk shoot-through due to insufficient bootstrap voltage, triggering intermittent dropout or thermal shutdown.

Can MP2348GTL-Z operate with a 3.3V input supply?

No. The absolute minimum input voltage is 4.2V per datasheet specifications. At 3.3V, the internal regulator cannot establish stable VCC, preventing proper gate drive and causing startup failure or erratic switching. For sub-4.2V inputs, consider the MP2318 (2.5V–6V range) or MP2308 (2.5V–6V, 2A) as functional alternatives.

How does pre-biased start-up function in MP2348GTL-Z?

During pre-biased start-up, the MP2348GTL-Z detects existing output voltage at the FB pin and delays high-side switching until the BST capacitor is refreshed and the soft-start voltage exceeds the sensed output. This prevents reverse current flow through the low-side MOSFET and ensures monotonic VOUT rise-even when the output is already charged to 3.3V prior to enable assertion.

What is the purpose of the 499kΩ resistor on the MODE pin?

The 499kΩ resistor from MODE to GND configures the MP2348GTL-Z for PFM operation with ultrasonic mode (USM), forcing minimum switching frequency >20kHz during light loads. This avoids audible coil whine in sensitive audio/display environments while maintaining >85% efficiency at 10–50mA loads-unachievable in forced PWM mode.

Does MP2348GTL-Z support output voltages below 0.8V?

No. The internal reference is fixed at 802mV, and the FB pin is designed for resistive divider configurations yielding VOUT ≥ 0.8V. Attempting sub-0.8V outputs violates the error amplifier's common-mode input range and results in regulation loss. For <0.8V applications, use the MP2335 (0.6V reference) or MP2315 (0.6V, 3A) with compatible feedback architecture.

What thermal derating applies to MP2348GTL-Z in a 2-layer PCB layout?

On a standard 2-layer JEDEC board (64mm×48mm), θJA is 130°C/W. At 25°C ambient, maximum continuous power dissipation before thermal shutdown is 0.96W. With 4A output at 3.3V (13.2W out), typical losses are ~0.8W at 12V input-well within limit. However, above 3A load or >19V input, copper pour and thermal vias under the exposed pad are mandatory to sustain full rating.