Monolithic Power Systems Inc. MPQ9843GL-P

Overview

MPQ9843GL-P from Monolithic Power Systems is a 36V, 3A synchronous step-down DC/DC converter with AEC-Q100 Grade-1 qualification, 14μA no-load quiescent current, and programmable 350kHz–2.5MHz switching frequency. It integrates 125mΩ high-side and 55mΩ low-side MOSFETs in a QFN-16 (3mm×4mm) package and delivers regulated output for automotive infotainment power rails.

For engineers reviewing the MPQ9843GL-P datasheet, MPQ9843GL-P pinout, MPQ9843GL-P application, or MPQ9843GL-P equivalent, key selection criteria include its ultra-low IQ for battery-backed systems, AEC-Q100 compliance for under-hood use, 80ns minimum on-time for high-duty-cycle operation, and PG signal with ±5% accuracy for system sequencing.

Technical Context

The MPQ9843GL-P uses peak-current-mode control with internal error amplifier and PWM comparator to deliver fast transient response and stable loop behavior across wide input (3.3V–36V) and load (0–3A) ranges. Its architecture supports both forced CCM and Advanced Asynchronous Mode (AAM), selectable via SYNC pin logic state prior to startup.

It features integrated bootstrap refresh circuitry, precision 0.8V feedback reference (±1.5% over temperature), hiccup-mode over-current protection, and thermal shutdown at 170°C with 20°C hysteresis. The BIAS pin enables external 5–18V bias supply to reduce power loss and improve efficiency at high VIN.

Key Specifications

Pinout & Package

MPQ9843GL-P is housed in a thermally enhanced QFN-16 (3mm × 4mm, 0.5mm pitch) package with wettable flanks (AEC-Q100 qualified). Exposed thermal pad (Pin 4/9 PGND) must be soldered to PCB ground plane for optimal thermal performance (θJA = 48°C/W, θJC = 11°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4433GQ-AEC1 and TPS543B20RHLT, the MPQ9843GL-P uniquely balances AEC-Q100 Grade-1 compliance, 3A capability, 14μA IQ, and 3.3V–36V input range in a compact 3mm×4mm package-making it optimal for space-constrained, battery-sensitive automotive modules.

Availability

MPQ9843GL-P is available at Aetrix Electronics and suitable for automotive infotainment, ADAS camera power, and industrial telematics requiring stable component supply with AEC-Q100 assurance and long-lifecycle support.

Supply support for MPQ9843GL-P 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 over two decades of expertise in DC/DC conversion and automotive-grade power solutions.

The MPQ9843 belongs to MPS's AEC-Q100-qualified automotive buck converter family, designed specifically for demanding vehicle subsystems requiring ultra-low quiescent current, high input voltage tolerance, and robust EMI performance.

FAQ

What is the maximum allowable input voltage for MPQ9843GL-P?

The absolute maximum input voltage is 40V, but the recommended operating range is 3.3V to 36V. Operation above 36V risks exceeding the device's safe operating area during transients like load dump, even with external clamping. Designers should ensure transient suppression limits VIN to ≤36V under all conditions.

How does the BIAS pin improve efficiency?

When supplied with 5–18V, the BIAS pin powers the internal gate drivers and control circuitry directly, bypassing the internal LDO that would otherwise drop VIN to ~5V. This reduces power dissipation-especially at high VIN-and improves full-load efficiency by up to 3 percentage points compared to BIAS-floating operation.

Can MPQ9843GL-P operate with a 3.3V input and 3.3V output?

Yes-the 80ns minimum on-time enables 100% duty cycle operation, allowing dropout-free regulation at VIN = VOUT. In this case, the device operates in 100% synchronous rectification mode with the low-side MOSFET conducting continuously, maintaining regulation down to 3.3V input without external diode assistance.

What is the purpose of the PHASE pin?

The PHASE pin selects whether the internal switching waveform aligns in-phase or 180° out-of-phase with an external SYNC clock. This enables interleaving of multiple MPQ9843GL-P devices to reduce input/output ripple and EMI peaks-critical in multi-rail automotive systems where synchronized noise summation must be avoided.

Is the PG signal compatible with 1.8V logic systems?

Yes-the PG pin is open-drain and can be pulled up to any logic rail (1.8V, 3.3V, or 5V). Its VOL is guaranteed ≤0.4V at 2mA sink current, ensuring clean low-state recognition across all common I/O voltages. No level-shifting circuitry is required for interface with low-voltage MCUs.

Does MPQ9843GL-P support external frequency synchronization above 2.5MHz?

No-the SYNC input accepts only 350kHz to 2.5MHz clocks. Attempting to drive SYNC above 2.5MHz may cause erratic switching or failure to lock. For higher-frequency operation, use the internal FREQ resistor setting (e.g., 27kΩ yields 2.5MHz nominal) and rely on internal oscillator tolerance (±15%).

How is thermal performance affected by the wettable flank package?

The wettable flank feature enables automated optical inspection (AOI) of solder joints on the QFN perimeter, improving manufacturing yield and field reliability-but does not alter thermal resistance. θJA remains 48°C/W (JESD51-7, 4-layer board); thermal performance depends solely on PCB copper area, vias, and thermal pad solder coverage.