Monolithic Power Systems Inc. MPQ2420GF-P

Overview

MPQ2420GF-P from Monolithic Power Systems is a 75V, 0.3A AEC-Q100 Grade 1 synchronous step-down DC/DC converter with integrated high- and low-side MOSFETs (1.2Ω/0.45Ω), programmable soft-start, and an integrated window watchdog for automotive safety-critical power rails. It operates from 4.5V to 75V input, delivers ±1% FB reference accuracy at room temperature, and features 5μA shutdown current - enabling reliable operation in battery-backed ADAS camera modules, engine control units, and infotainment power supplies.

For engineers reviewing the MPQ2420GF-P datasheet, MPQ2420GF-P pinout, MPQ2420GF-P application, or MPQ2420GF-P equivalent, key selection criteria include its 75V input capability, dual-mode watchdog timing (short/long window), TSSOP-16 EP thermal performance (θJA = 45°C/W), and AEC-Q100 qualification for automotive under-hood environments.

Technical Context

The MPQ2420GF-P implements a current-mode PWM control architecture with zero-current detection (ZCD) for discontinuous conduction mode (DCM) efficiency optimization across light loads. Its integrated watchdog uses an external TIMER resistor to set timeout periods (e.g., 880μs ±10% with 51kΩ), and supports MODE-selectable short-window (15/10 cycle) or long-window (1500/1000 cycle) reset behavior synchronized via WDI pulses.

It employs a bootstrap-driven high-side gate driver with internal 5V BST regulation, UVLO thresholds of 4.2V (rising) / 3.75V (falling), and thermal shutdown at 175°C with 20°C hysteresis. The BIAS pin enables efficiency improvement by powering internal regulators from the output rail when VBIAS > 2.9V.

Key Specifications

Pinout & Package

TSSOP-16 EP package with exposed thermal pad connected to GND for optimal heat dissipation (θJA = 45°C/W on 4-layer PCB). Pin numbering follows standard top-view orientation with Pin 1 at bottom-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck converter with watchdog applications.

Compared with MPQ2420GF-P, MPQ2420GJ-AEC1 trades thermal performance for footprint reduction, while LM61480-Q1 offers higher current but lacks on-chip watchdog - making MPQ2420GF-P uniquely suited for ASIL-B-compliant systems needing single-chip power + safety supervision.

Availability

MPQ2420GF-P is available at Aetrix Electronics and suitable for automotive ADAS, engine control, infotainment, and telematics applications requiring stable component supply with AEC-Q100 traceability and long-term lifecycle support.

Supply support for MPQ2420GF-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, and global manufacturing partnerships.

The MPQ2420 product line targets automotive power conversion with integrated safety features, designed specifically for ASIL-B-compliant subsystems requiring wide-input, low-IQ, and watchdog-supervised DC/DC regulation.

FAQ

What is the maximum allowable input voltage for MPQ2420GF-P?

The absolute maximum input voltage (VIN) is +80V, but the recommended operating range is 4.5V to 75V. Operation beyond 75V risks exceeding safe operating area limits of the internal MOSFETs and may trigger overvoltage protection or cause permanent damage. Transient spikes up to 80V are tolerated per ABS MAX rating, but sustained operation above 75V is not guaranteed.

How does the MODE pin affect watchdog behavior?

The MODE pin selects between short-window (MODE = low) and long-window (MODE = high) operation. In short mode, the watchdog expects WDI pulses within 15 cycles (close) and 10 cycles (open); in long mode, windows expand to 1500 and 1000 cycles. This allows matching watchdog timing to MCU boot duration or task loop intervals without firmware modification.

Can MPQ2420GF-P operate without connecting the BIAS pin?

Yes - the device functions with BIAS unconnected, using VIN to power internal regulators. However, connecting BIAS to the regulated output (2.9V–5.5V) improves conversion efficiency by reducing gate drive losses and enabling higher LS-FET drive strength. Leaving BIAS open is acceptable for non-efficiency-critical designs but forfeits this benefit.

What is the purpose of the /WD_DIS pin, and what happens when it is left floating?

The /WD_DIS pin disables the watchdog when pulled low; it has a weak internal pull-up, so leaving it unconnected enables the watchdog by default. This design ensures fail-safe operation - if the pin is accidentally disconnected or driven high, watchdog supervision remains active, preventing silent system failures in safety-critical applications.

How is the soft-start time determined, and can it be adjusted post-design?

Soft-start time is set by an external capacitor from SS to GND; typical values range from 1nF to 100nF, yielding ramp times from ~1ms to >100ms. The SS pin sources a constant 5.5μA current, so time ≈ (C × 1V) / 5.5μA. This capacitor is easily changed on PCB revisions or prototypes, enabling tuning of inrush current and output stability without modifying the IC.

Does MPQ2420GF-P support forced PWM mode, or is it strictly auto-frequency scaling?

MPQ2420GF-P uses automatic frequency scaling (pulse-frequency modulation) only - it lacks a forced PWM pin or register setting. Under light load, switching frequency decreases to reduce gate and switching losses, improving efficiency. There is no provision for fixed-frequency operation; this is inherent to its ZCD-based DCM control architecture.

What is the minimum inductor value supported, and how is it calculated?

The minimum inductor is constrained by the 115ns minimum on-time and maximum input voltage: LMIN = (VIN(MAX) × tON(MIN)) / IPEAK. With VIN(MAX) = 75V and IPEAK = 810mA, LMIN ≈ 10.5μH. Using smaller inductors risks peak current limit triggering and unstable operation; recommended values are ≥22μH for robust 0.3A output across full input range.