Monolithic Power Systems Inc. MP2315GJ-P

Overview

MP2315GJ-P from Monolithic Power Systems is a synchronous step-down DC-DC converter IC with integrated 90mΩ/40mΩ MOSFETs, delivering 3A continuous output current across 4.5V–24V input range, fixed 500kHz switching frequency, and adjustable 0.8V–VIN output voltage. It operates in current-mode control with AAM power-save mode, OCP hiccup protection, and thermal shutdown-used in notebook I/O power rails where compact size and high efficiency at light-to-heavy loads are critical.

For engineers reviewing the MP2315GJ-P datasheet, MP2315GJ-P pinout, MP2315GJ-P application, or MP2315GJ-P equivalent, key selection criteria include its TSOT23-8 package footprint, EN/SYNC dual-function pin for enable and external clock synchronization (200kHz–2MHz), BST bootstrap requirement, and FB voltage accuracy of 779–803mV at 25°C.

Technical Context

The MP2315GJ-P employs peak current-mode control with internal 0.8V reference and optimized compensation, enabling fast transient response and stable loop behavior without external compensation components. Its AAM (Advanced Asynchronous Modulation) logic dynamically transitions between PFM and CCM based on COMP voltage versus externally set VAAM threshold.

It integrates a 5V internal VCC regulator powered from VIN, bootstrap driver with UVLO (2.2V rising threshold), and cycle-by-cycle over-current protection that triggers hiccup mode upon sustained short-circuit conditions-ensuring robust operation under fault conditions while minimizing thermal stress.

Key Specifications

Pinout & Package

MP2315GJ-P is housed in an 8-pin TSOT23 package (2.9mm × 1.6mm × 0.85mm), optimized for space-constrained applications. The exposed pad is not electrically connected and must be thermally anchored to PCB copper for improved heat dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2315GJ-P, MP2393GQ-P offers higher current capability and broader input range for future-proofing, while RT7295BGSP trades light-load efficiency for simpler control and guaranteed CCM-making it suitable for noise-sensitive constant-frequency applications where efficiency at <100mA is secondary.

Availability

MP2315GJ-P is available at Aetrix Electronics and suitable for notebook I/O power, digital set-top box core supplies, and flat panel display logic rails requiring stable component supply and long-term obsolescence management.

Supply support for MP2315GJ-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.

The MP2315 belongs to MPS's high-density synchronous buck converter product line, engineered for space-constrained computing and consumer electronics where integration, efficiency, and thermal performance are prioritized over ultra-low quiescent current.

FAQ

What is the minimum recommended input capacitance for MP2315GJ-P?

A 22μF X5R/X7R ceramic capacitor is recommended at the IN pin, placed as close as possible to Pins 2 and 4. This value ensures adequate RMS current handling (≥1.5A) and limits input ripple to <100mV under 3A load at 24V input. A 0.1μF ceramic should be added in parallel if using bulk tantalum or electrolytic input caps.

Can MP2315GJ-P operate without an external bootstrap diode?

Yes-MP2315GJ-P uses internal bootstrap charging via VIN through an internal diode and RC network. An external Schottky diode (e.g., IN4148) from VCC to BST is optional and only beneficial when VOUT ≥ 3.3V and duty cycle exceeds 65%, improving high-load efficiency by ~1–2%.

How does the AAM pin affect light-load efficiency and stability?

The AAM pin sets the COMP voltage threshold that triggers PFM entry. Lower AAM voltage improves stability and reduces output ripple but degrades light-load efficiency and transient response. Optimal setting balances these trade-offs-typically 200–400mV for 5V output-using a resistor calculated as R = VAAM / 6.2μA.

Is MP2315GJ-P pin-compatible with MP2393GQ-P?

No-while both are 8-pin TSOT23 buck converters, MP2393GQ-P has a different pinout: Pin 1 is EN/SYNC (not AAM), Pin 5 is GND (not BST), and Pin 6 is BST (not EN/SYNC). Layout redesign and schematic updates are required for migration.

What happens during thermal shutdown, and how does recovery work?

When junction temperature exceeds 150°C, MP2315GJ-P disables switching and holds all drivers off. Recovery occurs only after die temperature falls below ~130°C (20°C hysteresis), at which point soft-start reinitiates. No external reset is needed, but repeated cycling indicates insufficient PCB copper or airflow.

Does MP2315GJ-P support output voltages below 0.8V?

No-the internal reference is fixed at 0.8V, and the FB pin is designed for resistive divider configurations yielding VOUT ≥ 0.8V. Attempting sub-0.8V regulation violates the error amplifier's common-mode input range and causes instability or regulation failure.

What is the maximum allowable EN pin voltage, and why is current limiting necessary?

The EN pin is clamped internally to ~6.5V. To prevent exceeding the 100μA absolute maximum input current rating when pulled up to VIN > 6.5V, a series resistor ≥100kΩ is required. Without it, excessive current flows into the clamp diode, causing self-heating and potential reliability degradation.