MP9943GQ-Z (MPS) | MPS High-Frequency Synchronous Step-Down DC-DC (Buck) Power IC

Description: MPS high-frequency synchronous step-down DC-DC (Buck) power IC. Integrated high-side and low-side MOSFETs, compact QFN-8 (3×3mm) package, with Power Good (PG) signal, 3A peak output.

## Key Specifications

- Input Voltage: 4V~30V continuous operation, 36V maximum transient voltage

- Output: 0.8V~28.5V adjustable, 3A peak

- Switching Frequency: Fixed at 410kHz, supports external clock synchronization (200kHz~2.2MHz)

- Integrated MOSFETs: 85mΩ high-side / 55mΩ low-side on-resistance

- Junction Temperature Range: -40℃ ~ +125℃, industrial grade

- Package: QFN-8, 3×3mm

- Quiescent Current: 500μA (Power Save Mode at light load)

## Features

1. Synchronous Step-Down Conversion: Converts high-voltage DC to low-voltage DC. Synchronous rectification architecture delivers high efficiency and low heat generation.

2. Power Good (PG) Signal: Indicator signal triggered when output voltage stabilizes, used by host MCU for power-up sequence control.

3. Internal Soft-Start: Gradually ramps up output voltage at power-on to suppress inrush current and protect downstream loads.

4. Power Save Mode (PSM) at Light Load: Reduces power consumption under light load conditions to improve standby efficiency.

5. Frequency Synchronization: Supports external clock synchronization to reduce system EMI.

6. Comprehensive Protections

   - Over-current Protection (hiccup mode, auto-retry after fault)

   - Thermal Shutdown Protection: Automatically shuts down when temperature exceeds threshold

   - Short-circuit Protection

## Applications

- Industrial Control: PLCs, industrial controllers, industrial boards, sensor power supplies

- Communication Equipment: Optical modules, small distributed power supplies

- Smart Home & Smart Hardware Power

- Automotive Auxiliary Systems: Supports cold-start high-duty-cycle scenarios (auxiliary power, non-AEC-Q100 automotive grade)

- Printers, small embedded systems, robot control boards

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> Advantages: Wide input voltage range to withstand 24V industrial power surges; minimal external components, small PCB footprint, ideal for compact board designs.