Monolithic Power Systems Inc. MPQ4475GR-E-AEC1-Z

Overview

MPQ4475GR-E-AEC1-Z from Monolithic Power Systems is an AEC-Q100 Grade 1 qualified synchronous step-down converter with integrated USB charging port identification and current-limit switch. It delivers 2.5A continuous output at fixed 5V with programmable line drop compensation, operates from 7V–36V input, and supports BC1.2 DCP, Divider, and 1.2V/1.2V auto-detection modes for automotive USB smart charging applications.

For engineers reviewing the MPQ4475GR-E-AEC1-Z datasheet, MPQ4475GR-E-AEC1-Z pinout, MPQ4475GR-E-AEC1-Z application, or MPQ4475GR-E-AEC1-Z equivalent, key selection considerations include its triple-frequency selectability (120/250/350 kHz), ±8kV HBM ESD rating on DP/DM/USB pins, hiccup-mode over-current protection, thermal shutdown at 165°C, and QFN-25 (4mm×4mm) package with exposed thermal pad.

Technical Context

The device integrates a peak-current-mode controlled buck regulator with internal 40mΩ/32mΩ HS/LS MOSFETs and a dedicated 24mΩ USB power switch. Its control logic implements frequency dithering at 120kHz, dynamic OVP threshold adjustment based on load current, and intelligent line drop compensation using sensed USB current to maintain terminal voltage within 4.75–5.25V across cable impedance variations.

Auto-detection uses a state machine to identify BC1.2 DCP, Divider, and 1.2V/1.2V charging protocols without external components. The EN pin features 7.6V Zener clamping and 1MΩ internal pull-down, while soft-start time is fixed at 1.65ms and hiccup off-time is 0.5s for sustained overloads.

Key Specifications

Pinout & Package

MPQ4475GR-E-AEC1-Z is housed in a thermally enhanced QFN-25 (4mm × 4mm) package with exposed thermal pad (Pin 25). The package supports high-power dissipation (θ_JA = 44°C/W) and requires PCB layout with multiple vias to internal ground planes for thermal management.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar USB-integrated buck converter applications.

Compared with MPQ4475GR-E-AEC1-Z, MPQ4475GR-AEC1-Z omits critical USB protocol logic and cannot autonomously detect BC1.2 devices, while TPS65987D targets USB-C infrastructure and lacks integrated power conversion-neither offers drop-in replacement capability.

Availability

MPQ4475GR-E-AEC1-Z is available at Aetrix Electronics and suitable for automotive infotainment systems, ADAS camera modules, telematics control units, and commercial vehicle fleet trackers requiring stable component supply with AEC-Q100 assurance.

Supply support for MPQ4475GR-E-AEC1-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 MPQ4475 product line delivers integrated power management solutions for automotive USB charging, combining buck conversion, USB port control, and AEC-Q100 reliability in a single QFN package for space-constrained in-vehicle systems.

FAQ

What is the purpose of the VDROP pin and how does it affect output regulation?

The VDROP pin selects line drop compensation amplitude (130mV/GND, 400mV/float, 280mV/VCC) to counteract voltage loss across PCB traces or cables. It scales the output voltage rise proportionally to load current, ensuring 5V ±2.5% is maintained at the USB connector rather than at the IC's OUT pin-critical for long-harness automotive installations.

Does MPQ4475GR-E-AEC1-Z support USB-C or only USB-A charging protocols?

MPQ4475GR-E-AEC1-Z supports only legacy USB-A charging protocols: BC1.2 Dedicated Charging Port (DCP), Divider Mode, and 1.2V/1.2V Mode. It does not implement USB-C, Power Delivery (PD), or Alternate Mode signaling-those require separate controllers like TPS65987D or CYPD3177.

How is thermal performance managed in the QFN-25 package during 2.5A operation?

Thermal management relies on the exposed thermal pad (Pin 25) soldered to a large internal ground plane with ≥6 thermal vias. With proper PCB layout per MPS AN-107, junction-to-ambient thermal resistance is 44°C/W, allowing continuous 2.5A operation at +85°C ambient when θ_JA is reduced to ≤35°C/W via board-level heatsinking.

Can the FREQ pin be left floating for EMC-sensitive automotive applications?

Yes-floating FREQ configures 120kHz switching with built-in frequency dithering (triangular spread spectrum), reducing peak EMI by up to 10dB compared to fixed-frequency operation. This mode is explicitly recommended in automotive EMI-critical zones such as instrument clusters and HUD power supplies.

What happens during a USB output short-circuit event?

At >2.75A, the USB switch enters foldback current limit (70% of limit), then triggers hiccup mode after 5ms: 5ms on-time followed by 500ms off-time. This limits average power dissipation to <1.5W, preventing thermal damage while maintaining visibility of the fault condition to system monitoring circuitry.

Is the EN pin compatible with direct connection to automotive 12V battery rail?

Yes-EN has a 7.6V Zener clamp and accepts up to 10V. To connect directly to 12V, use a pull-up resistor ≥113kΩ (calculated as (36V − 10V)/230µA) to limit current below 230µA and prevent Zener overstress during load-dump transients.

How does the device handle pre-biased output conditions during startup?

When OUT is pre-biased above the soft-start ramp voltage, the MPQ4475GR-E-AEC1-Z disables both HS and LS switches until the internal SS capacitor voltage exceeds the feedback reference (1V). This prevents reverse current flow and ensures monotonic startup without output voltage undershoot or overshoot.