Monolithic Power Systems Inc. MP2420GF-Z

Overview

MP2420GF-Z from Monolithic Power Systems is a 75V, 0.3A synchronous step-down DC/DC converter with integrated high- and low-side MOSFETs (1.2Ω/0.45Ω R_DS(on)), programmable soft-start, and an integrated window watchdog for system-level fault detection. It operates across 4.5V–75V input, delivers adjustable output down to 1V, and features 5μA shutdown current-enabling use in automotive battery systems where wide VIN and ultra-low quiescent power are critical.

For engineers reviewing the MP2420GF-Z datasheet, MP2420GF-Z pinout, MP2420GF-Z application, or MP2420GF-Z equivalent, key selection criteria include its dual-function watchdog timing modes (short/long window), thermal shutdown at 175°C, FB voltage tolerance of ±2% over temperature, and TSSOP-16 EP package with exposed pad for thermal management.

Technical Context

The MP2420GF-Z implements a current-mode PWM control architecture with zero-current detection (ZCD) and precision 1V internal reference, enabling stable regulation across load transients and input variations. Its integrated 1.2Ω high-side and 0.45Ω low-side MOSFETs support up to 0.3A continuous output while minimizing conduction losses in high-voltage automotive rails.

The device embeds a fully autonomous window watchdog with external timer resistor (RTIMER) programming, MODE-selectable short/long window operation, and /WD_DIS disable functionality-providing hardware-level MCU supervision independent of the DC/DC regulation loop. Power-on reset (POR) and under-voltage lockout (UVLO) thresholds (4.2V rising / 3.75V falling) ensure robust startup sequencing in noisy 12V/24V/48V vehicle electrical systems.

Key Specifications

Pinout & Package

TSSOP-16 EP package with exposed thermal pad soldered to PCB ground plane for optimal junction-to-ambient thermal resistance (θ_JA = 45°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ2420GF-AEC1-Z, the MP2420GF-Z lacks AEC-Q100 qualification but matches all electrical and functional specs-making it ideal for cabin, telematics, or aftermarket applications. Versus LM5164QPWPRQ1, MP2420GF-Z integrates watchdog logic and MOSFETs, reducing external components and simplifying safety-critical supervision.

Availability

MP2420GF-Z is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC I/O power supplies, and battery-powered fleet trackers requiring stable component supply with guaranteed long-term availability.

Supply support for MP2420GF-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 mixed-signal ICs for power management, motion control, and automotive applications.

The MP2420 product line targets automotive and industrial DC/DC conversion with integrated protection and system supervision-designed to replace discrete power stages and external watchdogs in safety-conscious embedded systems.

FAQ

What is the maximum allowable input voltage for MP2420GF-Z?

The absolute maximum input voltage (VIN) is +80V, but the recommended operating range is 4.5V to 75V. Operation above 75V risks exceeding the UVLO hysteresis margin and may trigger premature shutdown during load-dump transients. The 75V upper limit ensures reliable regulation and thermal stability under sustained high-input conditions.

How does the watchdog timer period scale with RTIMER value?

The watchdog single-period time T (μs) is calculated as T = 15.75 × RTIMER(kΩ) + 73.5. For example, a 51kΩ resistor yields T ≈ 880μs. This linear relationship allows precise tuning of timeout windows for different MCU instruction cycle budgets without firmware changes.

Can MP2420GF-Z operate without connecting the BIAS pin?

Yes-the BIAS pin is optional. When left unconnected, the internal 2.6V regulator derives power from VIN. Connecting BIAS to a clean, regulated output (2.9V–5.5V) improves efficiency by reducing dropout losses and enhances LS-FET driver strength, especially at low VIN.

What is the purpose of the /WD_DIS pin, and what happens if it's 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 fail-safe behavior ensures supervision remains active unless explicitly disabled, supporting functional safety requirements in automotive designs.

Does MP2420GF-Z support adjustable switching frequency?

No-the MP2420GF-Z uses variable-frequency operation that automatically scales downward under light loads to reduce switching losses. The nominal frequency is not user-adjustable; instead, inductor value and load current determine actual fs, ranging from ~100kHz at full load to sub-100kHz at light loads.

How is thermal performance affected by the exposed pad connection?

The TSSOP-16 EP's exposed pad must be soldered to a minimum 100mm² copper area connected to GND. Without this, θ_JA degrades from 45°C/W to >70°C/W, risking thermal shutdown at ≤0.2A load. Proper pad connection lowers junction temperature by up to 35°C under full load at 85°C ambient.

What is the function of the POK output, and how is it used in system design?

POK is an open-drain "power good" signal that goes high when VOUT reaches ≥90% of its regulated value and remains high during normal operation. It is pulled low during startup, shutdown, or output undervoltage. System designers use POK to enable downstream logic or sequence multiple rails safely.