Monolithic Power Systems Inc. MPQ9846GL-AEC1-Z

Overview

MPQ9846GL-AEC1-Z from Monolithic Power Systems is a 36V, 0.6A synchronous step-down DC/DC converter with AEC-Q100 Grade 1 qualification, integrated 125mΩ high-side and 115mΩ low-side MOSFETs, 14μA no-load quiescent current, and programmable 350kHz–2.5MHz switching frequency. It delivers regulated output in automotive infotainment and ADAS power rails where wide input range (3.3V–36V) and low IQ are critical.

For engineers reviewing the MPQ9846GL-AEC1-Z datasheet, MPQ9846GL-AEC1-Z pinout, MPQ9846GL-AEC1-Z application, or MPQ9846GL-AEC1-Z equivalent, key selection criteria include its AEC-Q100 qualification, ultra-low 14μA quiescent current in no-load operation, 80ns minimum on-time for high-duty-cycle regulation, hiccup-mode over-current protection, and QFN-16 (3mm×4mm) package with exposed thermal pad.

Technical Context

The MPQ9846GL-AEC1-Z employs peak current mode control with internal compensation, enabling fast transient response and stable loop behavior across wide VIN and load ranges. Its AAM (Auto-Audio Mode) light-load efficiency enhancement and low-dropout mode extend operational range into high-duty-cycle scenarios (e.g., VOUT > 90% of VIN).

It supports external synchronization via the SYNC pin (350kHz–2.5MHz), phase alignment control via PHASE pin (in-phase or 180° out-of-phase), and bias supply optimization via BIAS pin (5V–18V). The open-drain PG signal asserts when VOUT is within ±10% of nominal, with deglitch timing of 30µs (rising) and 50µs (falling).

Key Specifications

Pinout & Package

MPQ9846GL-AEC1-Z is housed in a thermally enhanced QFN-16 (3mm × 4mm, 0.5mm pitch) package with exposed thermal pad (EP) for PCB-level heat dissipation. Pin 1 is marked by a dot; top marking includes "MP", year/week code, "9846", and lot number.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4420AGL-AEC1-Z and LM61460QPWRQ1, MPQ9846GL-AEC1-Z uniquely balances ultra-low IQ (14μA), fine-grained frequency control (350kHz–2.5MHz), and phase-synchronization capability in a compact 3mm×4mm footprint-making it optimal for space-constrained, EMI-sensitive, and battery-conscious automotive subsystems.

Availability

MPQ9846GL-AEC1-Z is available at Aetrix Electronics and suitable for automotive infotainment, digital instrument clusters, ADAS camera modules, and industrial telematics requiring stable component supply with AEC-Q100 compliance and long-term production continuity.

Supply support for MPQ9846GL-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 power management ICs, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MPQ9846 belongs to MPS's automotive-grade DC/DC converter product line, engineered specifically for AEC-Q100-compliant power conversion in safety-critical vehicle subsystems where low IQ, wide VIN, and EMI robustness are mandatory.

FAQ

What is the minimum input voltage required for MPQ9846GL-AEC1-Z to regulate a 3.3V output?

The MPQ9846GL-AEC1-Z supports dropout operation: it can maintain regulation with VIN as low as 3.3V for a 3.3V output (100% duty cycle), enabled by its low-dropout mode and 80ns minimum on-time. This is validated per Figure 23 in the datasheet under cold-crank conditions.

Does MPQ9846GL-AEC1-Z require an external bootstrap capacitor?

Yes. A 0.1μF X7R ceramic capacitor must be placed between BST and SW pins to provide gate-drive voltage for the internal high-side MOSFET. This capacitor charges during low-side conduction and is essential for proper high-side switching.

How is power-good (PG) functionality implemented, and what external components are needed?

PG is an open-drain output that pulls low when VOUT deviates >±10% from nominal. An external pull-up resistor (e.g., 100kΩ to 3.3V or 5V) is required. The PG signal has 30µs rising and 50µs falling deglitch timers to reject noise-induced false assertions.

Can MPQ9846GL-AEC1-Z synchronize to an external clock while also using the PHASE pin for phase alignment?

Yes. When SYNC is driven with a valid clock (350kHz–2.5MHz), the PHASE pin selects whether the internal switching waveform aligns in-phase or 180° out-of-phase with the SYNC edge. Pulling PHASE high selects in-phase; pulling low selects 180° out-of-phase.

What is the thermal performance difference between using the BIAS pin versus relying solely on VCC?

Connecting BIAS to a 5V–18V external supply reduces power dissipation in the internal VCC LDO, improving full-load efficiency by up to 2% and lowering die temperature by ~5°C at 0.6A - especially beneficial in sealed enclosures or high-ambient environments.

Is the MPQ9846GL-AEC1-Z compatible with ceramic output capacitors only, or can electrolytic types be used?

Ceramic output capacitors are strongly recommended due to their low ESR and stability across temperature. Electrolytic capacitors are not advised: their high ESR degrades transient response and may destabilize the current-mode control loop, risking oscillation or poor PG accuracy.

How does Auto-Audio Mode (AAM) affect electromagnetic emissions at light loads?

AAM reduces switching frequency at light loads (<10mA) to minimize switching losses, but it also spreads energy across a wider spectrum - lowering peak conducted/radiated EMI compared to fixed-frequency operation. This is confirmed by CISPR25 Class 5 test data in Figures 27–32 of the datasheet.