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MP9943GQ-Z
MP9943GQ-Z – High-Efficiency 3A Peak, 36V Synchronous Step-Down Converter
📌 Product Overview
The MP9943GQ-Z is a high-frequency, synchronous, rectified, step-down switch-mode converter from Monolithic Power Systems (MPS). It integrates built-in power MOSFETs to deliver a very compact solution that achieves a 3A peak output current with excellent load and line regulation over a wide input supply range [citation:2]. The synchronous mode operation provides higher efficiency across the entire output current load range, while current-mode control ensures fast transient response and simplifies loop stabilization [citation:1][citation:11].
MP9943GQ-Z – High-Efficiency 3A Peak, 36V Synchronous Step-Down Converter
📌 Product Overview
The MP9943GQ-Z is a high-frequency, synchronous, rectified, step-down switch-mode converter from Monolithic Power Systems (MPS). It integrates built-in power MOSFETs to deliver a very compact solution that achieves a 3A peak output current with excellent load and line regulation over a wide input supply range [citation:2]. The synchronous mode operation provides higher efficiency across the entire output current load range, while current-mode control ensures fast transient response and simplifies loop stabilization [citation:1][citation:11].
⚙️ Key Specifications
| Parameter | Value |
|---|---|
| Input Voltage Range | 4V to 36V (36V transient tolerance) [citation:1][citation:2][citation:5] |
| Output Current (Peak) | 3A [citation:1][citation:2][citation:3] |
| Output Voltage Range | 0.8V to 28.5V (Adjustable) [citation:1][citation:3][citation:6] |
| Switching Frequency | 410kHz [citation:1][citation:2][citation:3] |
| External Clock Sync Range | 200kHz to 2.2MHz [citation:1][citation:2][citation:5] |
| Internal Power MOSFETs RDS(ON) | 85mΩ (High-Side) / 55mΩ (Low-Side) [citation:1][citation:2][citation:5] |
| Quiescent Current (Iq) | 500 µA [citation:1] |
| Operating Temperature | -40°C to +125°C (Junction) [citation:1][citation:3][citation:4] |
| Package | QFN-8 (3mm × 3mm) [citation:1][citation:2][citation:3] |
✨ Key Features
- Wide 4V-to-36V Continuous Input Range – Supports a broad range of applications, including 12V and 24V industrial power systems, with 36V transient tolerance [citation:2][citation:5]
- 85mΩ/55mΩ Low RDS(ON) Internal Power MOSFETs – Enhances efficiency and reduces external component count [citation:1][citation:2]
- High-Efficiency Synchronous Mode Operation – Delivers efficiency >90% across a wide load range [citation:1][citation:2][citation:11]
- Fixed 410kHz Switching Frequency – Synchronizable with an external clock from 200kHz to 2.2MHz for system flexibility [citation:1][citation:2][citation:5]
- High Duty Cycle for Automotive Cold-Crank – Ensures reliable operation during vehicle startup voltage dips [citation:2][citation:5]
- Internal Power-Save Mode & Soft-Start – Optimizes light-load efficiency and limits inrush current during startup [citation:2][citation:5]
- Power Good (PGOOD) Indicator – Provides real-time output voltage monitoring and status signaling [citation:1][citation:2][citation:11]
- Comprehensive Protection Features – Includes over-current protection with hiccup mode, thermal shutdown, and under-voltage lockout (UVLO) [citation:1][citation:2][citation:5]
- Output Adjustable from 0.8V – Enables flexible output voltage configuration for various loads [citation:1][citation:2][citation:11]
- Compact QFN-8 (3mm×3mm) Package – Space-saving design with excellent thermal performance for high-density PCBs [citation:2][citation:5][citation:11]
📦 Packaging & Ordering Information
| Part Number | MP9943GQ-Z [citation:2][citation:3] |
| Package Type | QFN-8 (3mm × 3mm) [citation:1][citation:2] |
| Standard Package Quantity | 5,000 (Tape & Reel) [citation:2][citation:3][citation:6] |
| Part Status | Active – In Production [citation:3][citation:4] |
| MSL Rating | Level-1 (Unlimited) [citation:3][citation:6] |
| Lead Finish | NiPdAu [citation:3] |
🔧 Key Applications
- General Consumer Power Supplies – Multi-function printers (MFP), set-top boxes, and digital TVs [citation:1]
- Distributed Power Systems – Industrial and telecom power distribution networks [citation:1]
- Automotive Systems – Cigarette lighter adapters and infotainment systems with cold-crank capability [citation:2][citation:5]
- High-Power Consumer Electronics – Notebooks, gaming consoles, and portable devices requiring 3A output [citation:6][citation:11]
⚡ Working Principle & Architecture
The MP9943GQ-Z is a fully-integrated synchronous step-down converter operating from a wide 4V-to-36V input range. It integrates 85mΩ high-side and 55mΩ low-side power MOSFETs to achieve high efficiency and minimize external components [citation:1][citation:2]. The device employs a fixed-frequency, peak-current mode control architecture at 410kHz for fast transient response and excellent stability across the full input and load range [citation:1][citation:2][citation:11].
Key differentiator: The MP9943GQ-Z features a Power-Good (PGOOD) indicator and offers a high duty cycle for automotive cold-crank applications, making it an ideal solution for space-constrained designs requiring robust 3A current delivery and reliable performance in automotive and industrial environments [citation:2][citation:5][citation:11].
📋 Compliance & Environmental
| RoHS Status | ROHS3 Compliant [citation:3][citation:6][citation:9] |
| REACH Status | REACH Unaffected [citation:3][citation:6][citation:9] |
| US ECCN | EAR99 [citation:3][citation:6][citation:9] |
| HTSUS | 8542.39.0070 [citation:3][citation:6][citation:9] |
For complete technical documentation including the full datasheet and application notes, please visit the Monolithic Power Systems product page or contact your authorized distributor. The EV9943-Q-00A evaluation board is available for development and testing [citation:2][citation:5].
