Monolithic Power Systems Inc. MPQ2451DT-AEC1-LF-Z

Overview

MPQ2451DT-AEC1-LF-Z from Monolithic Power Systems is an AEC-Q100 Grade 1 qualified, non-synchronous step-down DC/DC converter with integrated 500mΩ high-side MOSFET, delivering up to 0.6A output current at 2MHz fixed switching frequency across a 3.3V–36V input range. It features internal compensation, 0.794V feedback reference, and precision cycle-by-cycle current limiting-designed for automotive body control modules, infotainment power rails, and industrial sensor nodes requiring robust operation from cold-crank to load-dump conditions.

For engineers reviewing the MPQ2451DT-AEC1-LF-Z datasheet, MPQ2451DT-AEC1-LF-Z pinout, MPQ2451DT-AEC1-LF-Z application, or MPQ2451DT-AEC1-LF-Z equivalent, key selection criteria include its 3μA shutdown current, thermal shutdown at 150°C, 130μA operating quiescent current, and compatibility with ceramic output capacitors without external compensation components.

Technical Context

The MPQ2451 employs current-mode control with a fixed 2MHz oscillator and internal soft-start (0.5–1ms ramp), enabling fast transient response and stable regulation under dynamic load steps. Its pulse-skipping mode reduces gate-driving and switching losses at light loads, while frequency fold-back prevents inductor current runaway during startup.

Operation relies on a bootstrap-driven high-side MOSFET with dedicated BST-to-SW capacitor charging path, UVLO thresholds of 2.7V (rising) and 2.3V (falling), and EN pin logic with 1.35–1.8V enable threshold and 400mV hysteresis-ensuring reliable sequencing in automotive 12V/24V systems.

Key Specifications

Pinout & Package

MPQ2451DT-AEC1-LF-Z is packaged in RoHS-compliant, lead-free SOT23-6L (TSOT23-6L compatible) with 0.95mm pitch and exposed pad not connected internally. Thermal resistance θ_JA = 220°C/W on 4-layer JEDEC PCB.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM61480-Q1 and TPS62903-Q1, MPQ2451DT-AEC1-LF-Z offers optimal balance of AEC-Q100 Grade 1 compliance, 36V input capability, and minimal external component count-making it preferred for cost-sensitive, space-constrained automotive body electronics where 0.6A output suffices.

Availability

MPQ2451DT-AEC1-LF-Z is available at Aetrix Electronics and suitable for automotive body control units, industrial sensor transmitters, and telematics GPS modules requiring stable component supply with guaranteed AEC-Q100 qualification and long-term production continuity.

Supply support for MPQ2451DT-AEC1-LF-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 core expertise in DC/DC conversion, motor drivers, and LED lighting controllers.

The MPQ2451 belongs to MPS's automotive-grade buck converter product line, engineered specifically for harsh-environment applications demanding AEC-Q100 qualification, wide input voltage tolerance, and minimal external component count.

FAQ

What is the maximum recommended output current for MPQ2451DT-AEC1-LF-Z in SOT23-6L package?

The device is rated for 0.6A continuous output current. In SOT23-6L, thermal limits constrain practical operation to ≤0.45A at 85°C ambient without forced airflow or enhanced PCB copper; derating is required above 60°C ambient to maintain junction temperature below 125°C.

Can MPQ2451DT-AEC1-LF-Z operate with a 2.5V input voltage?

No. The absolute minimum operating input voltage is 3.3V per datasheet specifications. At 2.5V, the internal regulator fails to power control circuitry, and UVLO prevents startup. For sub-3.3V inputs, consider the MPQ2452 (2.5V min) or external LDO pre-regulation.

Is an external bootstrap diode required for reliable operation?

An external bootstrap diode (e.g., BAT54) is recommended when V_OUT/V_IN > 65% (e.g., 5V out from 7V in) or when VIN ≤ 5V, as internal BST charging may be insufficient. It improves bootstrap capacitor recharge margin and prevents driver dropout during high-duty-cycle operation.

How does the MPQ2451 handle short-circuit conditions?

It implements cycle-by-cycle current limiting with 0.65–1.0A threshold. During sustained short, the device enters hiccup mode: shuts down for ~500ms after current-limit trips, then attempts restart. This prevents thermal damage while enabling automatic recovery once fault clears.

What is the purpose of the BST pin, and what capacitor value is recommended?

BST supplies gate drive voltage to the internal high-side MOSFET. A 0.1µF X7R ceramic capacitor must be placed between BST and SW pins, with minimal trace length. This capacitor is charged to ~5V during SW low phase and sustains gate drive during high-side conduction.

Does MPQ2451DT-AEC1-LF-Z support adjustable output voltages below 0.8V?

No. The internal feedback reference is fixed at 0.794V, and the datasheet specifies operation only for outputs ≥0.8V. Attempting lower outputs violates regulation accuracy and may cause instability; for sub-0.8V rails, use a dedicated low-V_REF converter or post-regulation LDO.

How does pulse-skipping mode affect EMI performance?

In pulse-skipping mode, switching becomes irregular and bursty, increasing broadband EMI energy below 10MHz. For EMI-sensitive applications, force PWM mode using external resistor on MODE pin (if supported) or select a converter with spread-spectrum clocking-MPQ2451 lacks this feature.