Monolithic Power Systems Inc. MP4313GRE-Z

Overview

MP4313GRE-Z from Monolithic Power Systems is a 45V, 3A synchronous step-down DC/DC converter with integrated 48mΩ/20mΩ high-side and low-side MOSFETs, frequency spread spectrum (FSS), and 18μA sleep-mode quiescent current. It supports automotive cold-crank operation via low-dropout mode and delivers stable 3.3V/5V outputs in battery-powered radios and industrial power systems.

For engineers reviewing the MP4313GRE-Z datasheet, MP4313GRE-Z pinout, MP4313GRE-Z application, or MP4313GRE-Z equivalent, key selection criteria include its 350–1000kHz configurable switching frequency, 100ns minimum on-time, AAM/FCCM mode selectability, and QFN-20 wettable flank package for automated optical inspection.

Technical Context

The MP4313GRE-Z employs current-mode control with fast loop response and integrates both power MOSFETs to eliminate external discrete switches. Its internal architecture includes a programmable frequency oscillator with FSS modulation, symmetric VIN routing for EMI reduction, and dual-mode operation (AAM for light-load efficiency or FCCM for fixed-frequency noise predictability).

It features dedicated pins for synchronization (SYNCIN/SYNCO), soft-start timing (SS), output voltage feedback (FB), and power-good monitoring (PG), all operating within –40°C to +125°C junction temperature range. Thermal shutdown at 170°C and hiccup-mode over-current protection ensure fault-tolerant operation in automotive and industrial environments.

Key Specifications

Pinout & Package

MP4313GRE-Z is housed in a QFN-20 (4mm × 4mm) wettable flank package, enabling solder joint inspection and improved thermal performance (θJA = 44°C/W on standard PCB). The exposed thermal pad must be connected to PGND for optimal power dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4313-AEC1, MP4313GRE-Z offers identical performance at lower qualification cost, while LM61480RQR trades EMI robustness and voltage range for higher current - making MP4313GRE-Z optimal for space-constrained, EMI-sensitive 45V applications.

Availability

MP4313GRE-Z is available at Aetrix Electronics and suitable for automotive infotainment, portable medical devices, and industrial PLC I/O modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP4313GRE-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.

The MP4313 belongs to MPS's automotive-grade DC/DC converter product line, engineered specifically for harsh-environment applications demanding wide VIN range, low EMI, and high reliability under thermal stress.

FAQ

What is the maximum allowable input voltage for MP4313GRE-Z?

The absolute maximum VIN rating is +50V, but the recommended operating range is 3.3V to 45V per datasheet specifications. Exceeding 45V may trigger overvoltage protection or degrade long-term reliability, even if within absolute ratings. For 48V battery systems, external clamping or pre-regulation is advised.

Does MP4313GRE-Z require an external bootstrap diode?

No - the MP4313GRE-Z integrates an internal bootstrap circuit and does not require an external diode. A ceramic capacitor (typically 0.1µF) must be placed between BST and SW pins to provide gate drive charge; incorrect placement or value causes HS-FET turn-on failure.

How is the switching frequency set, and what tolerance should be expected?

fSW is set by a resistor (RFREQ) from pin 20 (FREQ) to AGND, with typical values ranging from 62kΩ (470kHz) to 12kΩ (1000kHz). The fSW vs. RFREQ curve shows ±10% variation across temperature and process; for tight EMI control, use 1% tolerance resistors and validate in final layout.

Can MP4313GRE-Z operate without connecting the NC pin (pin 15)?

No - pin 15 (NC) must be connected to VCC or VOUT (≥3V); leaving it floating violates the absolute maximum ratings and may cause erratic enable behavior or latch-up. This requirement is explicitly stated in the Pin Functions table and differs from typical "no-connect" pins.

What is the purpose of the SYNCO pin, and how is it used in multi-rail designs?

SYNCO outputs a clock signal 180° out-of-phase with the internal oscillator or inverted relative to SYNCIN. In dual-MP4313 configurations, SYNCO from one device can drive SYNCIN of another to achieve interleaved operation, reducing input capacitor RMS current and improving thermal distribution.

Is the PG signal active-high or open-drain, and what pull-up voltage is supported?

PG is an open-drain output requiring an external pull-up resistor. It sinks current when VOUT is out-of-regulation (≤93% or ≥106.5% of VREF) and floats when in-spec. Pull-up voltage must match the monitored rail's logic level (e.g., 3.3V or 5V), with typical resistor values between 10kΩ and 100kΩ.

How does the MP4313GRE-Z handle thermal overload, and is recovery automatic?

At 170°C junction temperature, thermal shutdown disables switching until die temperature falls by 20°C (hysteresis). Recovery is fully automatic and does not require cycling EN or VIN; however, sustained overload will cause repeated shutdown cycles until root cause (e.g., insufficient heatsinking) is resolved.