Monolithic Power Systems Inc. MPQ2420GF

Overview

MPQ2420GF 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 watchdog timer, and 5μA shutdown current - designed for automotive power rails requiring functional safety redundancy in engine control units, ADAS camera modules, and battery management systems.

For engineers reviewing the MPQ2420GF datasheet, MPQ2420GF pinout, MPQ2420GF application, or MPQ2420GF equivalent, key selection criteria include its 4.5–75V input range, 1% FB reference tolerance at room temperature, TSSOP-16 EP thermal performance (θJA = 45°C/W), watchdog window mode configurability (short/long), and integrated power-on reset functionality.

Technical Context

The MPQ2420GF implements a current-mode PWM control architecture with zero-current detection (ZCD) and precision 1V internal reference (±2% over full temperature). Its adaptive frequency scaling reduces switching losses at light load while maintaining stable regulation across 1V–0.9×VIN output range.

Integrated watchdog logic operates independently of the DC/DC core, using external TIMER resistor (e.g., 51kΩ sets ~880μs period) to monitor MCU synchronization via WDI; MODE pin selects between short-window (t2=15 cycles, t3=10 cycles) or long-window (t4=1500 cycles, t5=1000 cycles) operation, with /WD_DIS enabling hardware disable.

Key Specifications

Pinout & Package

TSSOP-16 EP package with exposed thermal pad soldered to GND plane; 4.4mm × 5.0mm footprint, 1.2mm height, 0.65mm pitch; RoHS-compliant, halogen-free, AEC-Q100 Grade 1 qualified.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ2420GJ-AEC1, the MPQ2420GF offers superior thermal performance (45 vs. 60°C/W) and larger creepage for 75V isolation, while LM61480-Q1 trades integrated safety features for higher current and different reference architecture - making GF optimal for AEC-Q100 systems needing self-contained watchdog supervision.

Availability

MPQ2420GF is available at Aetrix Electronics and suitable for automotive ECU power rails, ADAS camera modules, telematics gateways, and battery-powered diagnostic tools requiring stable component supply with AEC-Q100 qualification and long-term lifecycle support.

Supply support for MPQ2420GF 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 delivers AEC-Q100-qualified DC/DC converters with integrated functional safety features - specifically engineered for automotive subsystems requiring robust 75V input handling, low IQ, and hardware-based MCU supervision.

FAQ

What is the maximum allowable input voltage for MPQ2420GF, and how does it handle load dump?

The absolute maximum input voltage is +80V, exceeding ISO 7637-2 Pulse 5a (75V/350ms) requirements. Its 4.5–75V operating range and internal 80V ABS MAX rating allow direct connection to automotive battery rails without external TVS clamping in most cases. The integrated UVLO (rising threshold 4.2V, hysteresis 0.45V) ensures clean startup after cranking dips.

How does the watchdog function interact with the DC/DC converter's power rails?

The watchdog operates from dedicated VCC and TIMER pins, electrically isolated from the main DC/DC output. VCC must be supplied with a stable 5V ±10% rail - typically derived from the MPQ2420GF's own output or a separate LDO - ensuring supervision remains active even if the main output fails or enters hiccup mode.

Can the MPQ2420GF be used without the BIAS pin connection?

Yes. When BIAS is left unconnected, the internal 2.6V regulator powers all circuitry from VIN. However, connecting BIAS to a 2.9–5.5V source (e.g., the regulated output) improves light-load efficiency by 2–3% and reduces thermal stress on the high-side MOSFET driver, especially at VIN > 24V.

What is the minimum inductor value required for stable operation at 75V input?

Per Equation (4) in the datasheet, L_MIN = (V_IN(MAX) × t_ON(MIN)) / I_PEAK. With V_IN(MAX) = 75V, t_ON(MIN) = 115ns, and I_PEAK = 720mA (typ), L_MIN = 11.9μH. A 15μH or higher inductor is recommended to maintain CCM operation and avoid subharmonic oscillation.

How is the power-good (POK) signal debounced, and what output voltage tolerance does it indicate?

POK uses an internal 40μs deglitch timer to reject noise-induced false triggers. It asserts high when V_OUT reaches ≥90% of the nominal value set by the FB divider and remains high until V_OUT drops below 85% (5% hysteresis), providing robust sequencing for downstream processors and memory.

Does the MPQ2420GF support adjustable switching frequency, or is it fixed?

Switching frequency is not user-adjustable but dynamically scales with load: it decreases under light load to reduce switching losses, then increases toward ~500kHz at full 0.3A output. This adaptive behavior is inherent to the current-mode ZCD control architecture and requires no external components.

What is the role of the /WD_DIS pin during functional safety validation testing?

/WD_DIS provides hardware-level watchdog disable for test modes - pulling it low suspends all watchdog functions (WDO, WDI monitoring, window timing) while leaving DC/DC regulation fully operational. This enables deterministic firmware debugging and ISO 26262 ASIL decomposition without safety mechanism interference.