Monolithic Power Systems Inc. MPQ5850GJ-Z

Overview

MPQ5850GJ-Z from Monolithic Power Systems is a 36V AEC-Q100 Grade 1 smart diode controller that replaces Schottky diodes with an external N-channel MOSFET for reverse input protection in automotive power rails. It delivers 20mV ultra-low dropout, 4μA shutdown current, and integrated boost converter for gate drive at cold-crank (0V VIN), enabling robust operation in ADAS camera and infotainment power supplies.

For engineers reviewing the MPQ5850GJ-Z datasheet, MPQ5850GJ-Z pinout, MPQ5850GJ-Z application, or MPQ5850GJ-Z equivalent, this device is selected for high-reliability reverse polarity protection where low quiescent current, ISO16750 transient compliance, and precise 20mV source-drain regulation are critical design requirements.

Technical Context

The MPQ5850GJ-Z implements dual-path gate control logic: fast pull-up (170mA) activates the external MOSFET when source-drain voltage exceeds +75mV, while fast pull-down (430mA) disables it within 1μs when reverse voltage drops below –4mV. Its internal boost converter operates in fixed peak-current mode (220mA limit) to sustain RES ≥12V even during 0V cold-crank events.

Regulation is achieved via real-time sensing of V_SD across SOURCE and DRAIN pins, with dedicated comparators for 20mV steady-state regulation, 75mV turn-on threshold, and –4mV reverse-turnoff threshold - all temperature-compensated across –40°C to +150°C.

Key Specifications

Pinout & Package

MPQ5850GJ-Z is housed in a thermally enhanced TSOT23-8 package (2mm × 3mm, 0.65mm pitch), optimized for high-density automotive PCB layouts with exposed pad thermal path.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar smart diode controller applications.

Compared with LM74700QDRRRQ1 and TPS26631PWPR, MPQ5850GJ-Z uniquely combines cold-crank operation (0V start), 20mV regulation, and 100kHz AC rectification - making it the only choice for high-frequency, low-dropout, battery-critical automotive systems without auxiliary bias rails.

Availability

MPQ5850GJ-Z is available at Aetrix Electronics and suitable for automotive ADAS camera power supplies, digital instrument clusters, infotainment head units, and telematics modules requiring stable component supply across extended temperature and transient stress conditions.

Supply support for MPQ5850GJ-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 power management ICs for automotive, industrial, and consumer applications.

The MPQ5850 product line targets AEC-Q100-compliant reverse protection in harsh automotive environments, emphasizing ultra-low dropout, cold-crank resilience, and integrated gate drive - specifically engineered for next-generation ADAS and infotainment power architectures.

FAQ

What external MOSFET parameters are critical for optimal MPQ5850GJ-Z performance?

The MPQ5850GJ-Z requires an N-channel MOSFET with R_DS(on) ≤ 5mΩ at V_GS = 10V and Q_g ≤ 30nC to ensure full enhancement at 20mV V_SD regulation and sub-2μs switching. Gate charge must be compatible with the 170mA/430mA drive strength to maintain <300ns rise/fall times under 10nF load.

How does the MPQ5850GJ-Z handle cold-crank events below 3V input?

During cold-crank, the MPQ5850GJ-Z remains functional by using its internal boost converter to generate ≥12V on the RES pin from DRAIN - even when DRAIN collapses to 0V. This sustains gate drive capability and maintains 20mV regulation without external bias, verified per ISO16750-2 Pulse 4a.

Can the MPQ5850GJ-Z be used for AC rectification, and what is the maximum frequency?

Yes - the MPQ5850GJ-Z supports AC rectification up to 100kHz, enabled by its fast 75mV turn-on and –4mV turn-off thresholds and 430mA pull-down strength. Performance is validated with 6V_PP, 1kHz sine wave input and 15nF gate capacitance, meeting ISO16750-2 transient immunity.

What is the role of the PG pin, and how should it be interfaced?

The PG pin is an open-drain indicator asserting low during RES undervoltage, fast pull-up timeout (>17μs), or chip disable. It must be pulled up externally (e.g., 10kΩ to 3.3V) and monitored by MCU GPIO. Floating PG causes undefined system fault reporting and violates AEC-Q100 diagnostic coverage requirements.

Is the TSOT23-8 package thermally sufficient for 5A continuous operation?

Yes - the TSOT23-8 package achieves θ_JA = 85°C/W on a 4-layer JEDEC board. At 5A with 20mV dropout (100mW dissipation), junction rise is ~8.5°C above ambient. For sustained 5A, a 25mm² copper pour under the exposed pad is recommended to maintain T_J < 125°C at 85°C ambient.

Does the MPQ5850GJ-Z require external compensation components?

No - all regulation loops (20mV V_SD, RES voltage, gate timing) are fully internal and factory-trimmed. Only mandatory external components are: 4.7μF DRAIN-to-GND ceramic capacitor, 1μF RES-to-DRAIN capacitor, and 68μH boost inductor between SW and DRAIN - no RC networks or feedback dividers needed.

How is reverse polarity protection implemented without a body diode?

The MPQ5850GJ-Z senses negative V_SD across SOURCE and DRAIN. When V_SD < –4mV, its 430mA pull-down rapidly discharges the MOSFET gate, turning off the channel before reverse current exceeds 100mA - effectively eliminating body diode conduction and preventing reverse battery drain.