Monolithic Power Systems Inc. MPQ4569GN-Z

Overview

MPQ4569GN-Z from Monolithic Power Systems is a 75V, 0.3A AEC-Q100 Grade 1 qualified synchronous step-down DC/DC converter with integrated high-side (1.2Ω) and low-side (0.45Ω) MOSFETs, 1% FB reference accuracy at 25°C, 5μA shutdown current, and SOIC-8 EP packaging - designed for automotive front-end power rails supplying infotainment or ADAS domain controllers from 12V/24V/48V battery systems.

For engineers reviewing the MPQ4569GN-Z datasheet, MPQ4569GN-Z pinout, MPQ4569GN-Z application, or MPQ4569GN-Z equivalent, key selection criteria include its 4.5–75V input range, programmable soft-start via external capacitor, POK output for system sequencing, thermal shutdown at 175°C, and bias pin support for efficiency optimization in high-voltage industrial power supplies.

Technical Context

The MPQ4569GN-Z implements a current-mode PWM control scheme with zero-current detection (ZCD), enabling discontinuous conduction mode (DCM) operation across light loads to maintain high efficiency. Its internal 1V reference feeds the FB comparator, while the VREF pin (QFN only) is absent - confirming SOIC-8 EP lacks reference output capability.

It integrates a dedicated BIAS pin that, when supplied ≥2.9V, powers the internal regulator independently of VIN, reducing switching losses and improving full-load efficiency. The bootstrap driver charges via VIN-to-BST path during low-side FET conduction, requiring ≥2.4V BST–SW differential for proper high-side gate drive.

Key Specifications

Pinout & Package

MPQ4569GN-Z is housed in an SOIC-8 EP (exposed pad) package with thermal-enhanced construction. The exposed pad must be soldered to a PCB thermal plane for reliable 0.3A operation at ambient temperatures up to +105°C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4569GQ-Z, the GN-Z offers BIAS pin support for efficiency tuning and better thermal performance in SOIC-8 EP; versus LM5164QDGSRQ1, it delivers lower I_Q, integrated POK, and broader 75V input - making it optimal for AEC-Q100-compliant, thermally constrained, and sequenced-power automotive systems.

Availability

MPQ4569GN-Z is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial 48V power supplies, and battery-powered telematics requiring stable component supply, long-term lifecycle assurance, and AEC-Q100-compliant sourcing.

Supply support for MPQ4569GN-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 design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MPQ4569 belongs to MPS's automotive-grade DC/DC converter product line, engineered specifically for harsh-environment applications demanding AEC-Q100 qualification, wide-input voltage tolerance, and ultra-low quiescent current.

FAQ

What is the maximum allowable input voltage for MPQ4569GN-Z?

The absolute maximum input voltage is +80V, but the recommended operating range is 4.5V to 75V. Operation above 75V risks exceeding internal MOSFET breakdown limits and invalidates AEC-Q100 qualification - sustained use beyond 75V may cause premature failure even if within absolute ratings.

Can the BIAS pin be left unconnected?

Yes, the BIAS pin can be left floating or tied to GND without damage, but doing so forfeits efficiency gains. When unconnected, the internal regulator draws from VIN, increasing gate drive losses - especially at high input voltages. For best efficiency, connect BIAS to a stable 2.9–5.5V rail such as the regulated output.

Does MPQ4569GN-Z support adjustable switching frequency?

No, MPQ4569GN-Z does not offer user-adjustable switching frequency. Its frequency varies dynamically with load and input/output conditions - scaling down under light load to improve efficiency and limiting peak frequency during short-circuit events to prevent inductor saturation and current runaway.

Is the POK output active-high or open-drain?

The POK pin is an open-drain output requiring an external pull-up resistor (typically 10kΩ to VOUT or VCC). It pulls low during shutdown or when VOUT drops below 90% of the nominal value; it floats HIGH when regulation is stable - enabling wired-OR sequencing with other power rails.

How is thermal performance affected by the SOIC-8 EP exposed pad?

The exposed pad significantly lowers thermal resistance: θ_JA is 48°C/W (vs 50°C/W for QFN-10) when soldered to ≥1in² copper area. Full thermal benefit requires minimum 6 thermal vias (0.3mm diameter) connecting the pad to inner-layer ground planes - insufficient vias or undersized copper will raise junction temperature above 125°C at 0.3A continuous load.

What happens if the SS capacitor is omitted?

Omitting the SS capacitor disables soft-start, causing immediate full-duty-cycle startup and potential output overshoot or inrush current exceeding 1A. This may trip upstream fuses or damage downstream capacitors - the SS pin must be connected to GND via a capacitor (e.g., 100nF for ~20ms ramp) for reliable operation.

Does MPQ4569GN-Z require an external bootstrap diode?

No, MPQ4569GN-Z integrates a bootstrap charging circuit with internal PMOS pass transistor - no external diode is needed. A 0.1μF ceramic capacitor between BST and SW is mandatory to sustain high-side gate drive; incorrect placement or capacitance causes erratic switching or dropout at high duty cycles.