Monolithic Power Systems Inc. MPQ2420GF-Z

Overview

MPQ2420GF-Z from Monolithic Power Systems is a 75V, 0.3A AEC-Q100 Grade 1 synchronous step-down converter with integrated high- and low-side MOSFETs (R_DS(on) = 1.2Ω / 0.45Ω), programmable watchdog timer, and 5μA shutdown quiescent current. It delivers regulated DC output in automotive power rails, battery-powered telematics modules, and industrial distributed supplies where input transients up to 80V must be tolerated.

For engineers reviewing the MPQ2420GF-Z datasheet, MPQ2420GF-Z pinout, MPQ2420GF-Z application, or MPQ2420GF-Z equivalent, key selection criteria include its 4.5–75V input range, integrated window watchdog with MODE-selectable timing windows, FB reference tolerance (±2% over temperature), soft-start capacitor control, and TSSOP-16 EP thermal performance (θ_JA = 45°C/W).

Technical Context

The MPQ2420GF-Z implements a current-mode PWM controller with zero-current detection (ZCD) for valley switching, enabling discontinuous conduction mode (DCM) operation at light loads to maintain efficiency. Its internal 1V reference (±2% over –40°C to +125°C) feeds an error amplifier that compares FB voltage against VREF to regulate output via duty-cycle adjustment of the 1.2Ω/0.45Ω integrated MOSFET pair.

The watchdog subsystem operates independently using TIMER pin resistor programming (e.g., 51kΩ sets ~880μs period), supports short-window (t₂/t₃) or long-window (t₄/t₅) modes via MODE pin logic level, and asserts WDO reset on timeout or WDI stall-ensuring fail-safe MCU supervision without external components.

Key Specifications

Pinout & Package

TSSOP-16 EP package with exposed thermal pad (pin 13 SW connects to internal switch node; exposed pad must be soldered to GND plane for θ_JA = 45°C/W performance).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ2420-AEC1, MPQ2420GF-Z offers identical performance in a tape-and-reel format optimized for SMT production, while LM5164QPWPRQ1 lacks integrated watchdog capability-requiring additional components and validation effort to meet automotive functional safety targets.

Availability

MPQ2420GF-Z is available at Aetrix Electronics and suitable for automotive infotainment power supplies, ADAS camera module bias rails, and industrial telematics gateways requiring stable component supply with AEC-Q100 Grade 1 assurance and long-term lifecycle support.

Supply support for MPQ2420GF-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 automotive-grade power management.

The MPQ2420 product line delivers integrated high-voltage buck regulators with safety features (watchdog, POR, POK) specifically designed for automotive and industrial applications demanding robustness, low quiescent current, and AEC-Q100 qualification.

FAQ

What is the maximum input voltage rating for MPQ2420GF-Z?

The absolute maximum input voltage (VIN) is +80V, with recommended operating range from 4.5V to 75V. This rating enables reliable operation during automotive load-dump events per ISO 7637-2 Pulse 5a, where transient voltages can reach 75V for 400ms. Exceeding 80V risks permanent damage to the integrated MOSFETs.

How does the watchdog timer period get set on MPQ2420GF-Z?

The watchdog period is set by an external resistor (RTIMER) connected between TIMER pin and GND. Using RTIMER = 51kΩ yields a nominal period of 880μs, calculated as T = 15.75 × RTIMER + 73.5 μs. The resistor value directly determines window timing for both short and long modes, with no calibration required.

Can MPQ2420GF-Z operate without the BIAS pin connected?

Yes - the device operates with BIAS unconnected, powered solely from VIN. However, connecting BIAS to the regulated output (2.9–5.5V) improves efficiency by reducing gate driver losses and enabling stronger LS-FET drive. Leaving BIAS floating increases quiescent current slightly but maintains full functionality.

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

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 behavior: if the pin is accidentally disconnected or floats, the watchdog remains active to supervise MCU operation.

Does MPQ2420GF-Z support adjustable output voltage, and how is it configured?

Yes - output voltage is adjustable via a resistive divider from VOUT to FB. With a 1.0V internal reference, VOUT = 1V × (1 + R1/R2). For example, R1 = 1200kΩ and R2 = 523kΩ sets 3.3V output. Feedback resistors in the MΩ range minimize no-load current draw and improve light-load efficiency.

What thermal derating applies to MPQ2420GF-Z in a standard 4-layer PCB layout?

With JEDEC-standard 4-layer board (2 oz copper, 1-in² GND plane), θJA = 45°C/W. At TA = 85°C, maximum continuous power dissipation is PD(MAX) = (150°C − 85°C) / 45°C/W = 1.44W. Exceeding this causes thermal shutdown at 175°C junction temperature, with 20°C hysteresis ensuring safe restart after cooling.

Is MPQ2420GF-Z pin-compatible with other members of the MPQ2420 family?

Yes - all MPQ2420 variants (including MPQ2420GF, MPQ2420-AEC1, and MPQ2420GJ) share identical TSSOP-16 EP pinout, electrical characteristics, and thermal behavior. Differences are limited to top marking, packaging format (tape-and-reel vs tray), and qualification grade documentation - not hardware compatibility.