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Monolithic Power Systems Inc. MPQ4559DQ-LF-Z
- Part No.:
- MPQ4559DQ-LF-Z
- Manufacturer:
- Monolithic Power Systems Inc.
- Package:
- 10-VFDFN Exposed Pad
- Datasheet:
-
MPQ4559DQ-LF-Z.pdf
- Description:
- IC REG BUCK ADJ 1.5A 10QFN
- Quantity:
- Payment:
- Shipping:
Inventory:5,000
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Product details
Overview
MPQ4559DQ-LF-Z from Monolithic Power Systems is an AEC-Q100 qualified, non-synchronous step-down DC/DC converter with integrated 250mΩ high-side MOSFET, delivering 1.5A output current across a 3.8V–55V input range and adjustable 0.8V–52V output. It operates at up to 2MHz switching frequency, features 140μA quiescent current, and supports automotive and industrial power rails requiring high-voltage buck conversion.
For engineers reviewing the MPQ4559DQ-LF-Z datasheet, MPQ4559DQ-LF-Z pinout, MPQ4559DQ-LF-Z application, or MPQ4559DQ-LF-Z equivalent, key selection criteria include its 2MHz programmable oscillator, thermal shutdown protection, frequency foldback during startup, bootstrap-driven high-side gate drive, and compatibility with ceramic-output-capacitor stability.
Technical Context
The MPQ4559DQ-LF-Z implements current-mode control with a transconductance error amplifier (120µA/V) and fast peak-current sensing for stable loop response. Its programmable oscillator uses an external resistor on the FREQ pin to set switching frequency from 0.7MHz to 1.3MHz (typ), with internal scaling down to zero under light load to minimize switching losses.
It integrates a floating high-side driver powered by a bootstrap capacitor charged via an internal regulator; BST-SW UVLO (2.2V, 150mV hysteresis) ensures reliable gate drive. Short-circuit protection reduces current limit to ~50% when FB ≈ 0V, and soft-start ramps internal reference from 0V to 2.6V to prevent output overshoot.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.8V to 55V - supports wide-range industrial and automotive battery/supply rails including 12V, 24V, and 48V systems. |
| Output Current | 1.5A continuous - sufficient for powering microcontrollers, sensors, and interface ICs in distributed power architectures. |
| Switching Frequency | Up to 2MHz (programmable via FREQ pin resistor) - enables compact magnetics and avoids AM radio/ADSL EMI bands. |
| Quiescent Current | 140µA - enables long battery life in always-on automotive modules and remote IoT nodes. |
| Feedback Reference | 0.800V ±20mV - precise voltage setting with <±2.5% tolerance over –40°C to +125°C for stable regulation. |
| High-Side RDS(ON) | 250mΩ (typ) - limits conduction loss at 1.5A, enabling >90% efficiency at mid-load in 12V→3.3V conversion. |
| Shutdown Current | 12µA - ultra-low off-state draw for system-level power gating in safety-critical applications. |
Pinout & Package
MPQ4559DQ-LF-Z is housed in a thermally enhanced 3mm × 3mm QFN-10 package with exposed pad for optimal PCB heat dissipation (θJA = 50°C/W on 4-layer board). Pin functions are validated per Monolithic Power Systems' official datasheet Rev. 1.01.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2 (SW) | Switch Node | Drives external Schottky diode; requires low-inductance layout to suppress ringing and ensure reliable bootstrap charging. |
| 3 (EN) | Enable Input | Positive logic control with 1.55V rising threshold; internal 1µA pull-up allows floating-enable operation. |
| 4 (COMP) | Error Amplifier Output | Interface for RC compensation network; sets loop bandwidth and phase margin for transient stability. |
| 5 (FB) | Voltage Feedback Input | Senses resistive divider output; compares to 0.8V internal reference to regulate VOUT. |
| 6 (GND) | Power Ground | Primary return path; exposed pad must be soldered to solid GND plane for thermal and EMI performance. |
| 7 (FREQ) | Frequency Programming | Connects to ground via resistor (e.g., 95kΩ → 1MHz); enables EMI optimization and layout flexibility. |
| 8, 9 (VIN) | Input Supply | Supplies internal regulators and high-side driver; requires local 4.7µF ceramic decoupling. |
| 10 (BST) | Bootstrap Supply | Charged from VIN through internal PMOS; requires 0.1µF ceramic capacitor between BST and SW. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 Grade 1 qualification | Validated for automotive ambient temperatures (–40°C to +125°C junction), supporting engine bay and ADAS subsystems. |
| Internal soft-start | 0.19–0.5ms ramp time prevents output overshoot and inrush current during cold start or fault recovery. |
| Ceramic capacitor stable | No minimum ESR requirement on output capacitor - simplifies design and improves reliability vs. electrolytic alternatives. |
| Frequency foldback | Reduces switching frequency during startup and short-circuit events to limit inductor current runaway and thermal stress. |
| Thermal shutdown with hysteresis | Triggers at 150°C junction temperature and re-enables at 130°C - prevents latch-up and enables self-recovery after overload. |
Applications
| Automotive Body Control Module | Industrial PLC I/O Power |
|---|---|
Use Scenario: Powering CAN transceivers, LIN drivers, and sensor interfaces in vehicle door modules and lighting controllers. IC Role / Device Role / Timing Role: Primary 5V/3.3V buck converter supplying MCU peripherals and communication ICs from 12V battery rail. Use Value: AEC-Q100 qualification and 55V input withstand capability ensure robust operation during load-dump transients (ISO 7637-2 Pulse 5a). | Use Scenario: Generating isolated 5V and 12V rails for digital I/O expansion cards in modular automation controllers. IC Role / Device Role / Timing Role: High-efficiency point-of-load regulator converting 24V field bus to logic-level supplies with minimal heatsinking. Use Value: 2MHz operation allows use of ≤10µH inductors, reducing board area and magnetic cross-talk in dense backplane layouts. |
| Battery-Powered Telematics Unit | Distributed Telecom Power |
Use Scenario: Power management in GPS/GLONASS tracking devices operating from 3.6V Li-ion or 12V vehicle auxiliary ports. IC Role / Device Role / Timing Role: Always-on buck converter maintaining RTC, cellular modem standby, and wake-up circuitry. Use Value: 140µA quiescent current extends battery runtime beyond 6 months in sleep mode without compromising startup responsiveness. | Use Scenario: Secondary 3.3V supply for FPGA configuration and SerDes bias in remote radio units (RRUs) fed from 48V telecom rectifiers. IC Role / Device Role / Timing Role: High-input-voltage step-down stage preceding LDOs or POL converters in multi-rail power trees. Use Value: 55V absolute max input rating accommodates 48V +20% surge conditions while maintaining regulated output without external clamping. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MPQ4572DQ-LF-Z | Successor device with improved 1.2A current limit, lower 100mΩ RDS(ON), and extended 60V input rating. | Designed for new designs requiring higher efficiency and longer lifetime; pin-compatible but not drop-in due to updated EN threshold and soft-start timing. | Select for production releases post-2023 where long-term availability and reduced thermal stress are prioritized. |
| LM5164QPWPRQ1 | TI part with 1A output, 65V input, and integrated bootstrap diode - eliminates external Schottky requirement but lacks AEC-Q100 Grade 1. | Targeted at cost-sensitive industrial applications; no automotive qualification, different compensation architecture (voltage mode). | Consider only if AEC-Q100 is not required and board space savings from integrated bootstrap diode outweigh loop stability trade-offs. |
Compared with MPQ4559DQ-LF-Z, MPQ4572DQ-LF-Z offers higher efficiency and longer product lifecycle but requires minor schematic updates; LM5164QPWPRQ1 trades automotive qualification for simplified layout and broader input range, making it suitable only for non-automotive industrial use cases.
Availability
MPQ4559DQ-LF-Z is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC power supplies, and battery-powered telematics requiring stable component supply despite its "Not Recommended for New Designs" status.
Supply support for MPQ4559DQ-LF-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 analog and power ICs, with core expertise in DC/DC conversion, motor drivers, and LED lighting controllers.
The MPQ45xx series targets high-voltage industrial and automotive power conversion, emphasizing AEC-Q100 compliance, wide input range, and integration of critical functions like bootstrap drivers and thermal protection.
FAQ
What is the recommended external bootstrap capacitor value for MPQ4559DQ-LF-Z?
A 0.1µF X7R ceramic capacitor rated for ≥16V must be placed directly between BST and SW pins. This value ensures stable gate drive under 2MHz operation and full-duty-cycle conditions. Larger values (>0.22µF) may cause startup delay or oscillation due to increased charging time and parasitic resonance.
Can MPQ4559DQ-LF-Z operate with an input voltage below 3.8V?
No - the absolute minimum operating input voltage is 3.8V per datasheet specifications. Below this, internal regulation fails and the device enters UVLO (undervoltage lockout) with 2.6V falling threshold. Attempting operation at 3.3V or lower will result in no switching and unregulated output.
Is the MPQ4559DQ-LF-Z pin-compatible with MPQ4559DN-LF-Z (SOIC8E)?
No - QFN10 (MPQ4559DQ-LF-Z) and SOIC8E (MPQ4559DN-LF-Z) packages have different pin counts, layouts, and thermal characteristics. The QFN version integrates SW on pins 1–2 and VIN on pins 8–9, while SOIC8E consolidates SW to pin 1 and VIN to pin 7. Layout redesign is mandatory for substitution.
Does MPQ4559DQ-LF-Z support synchronous rectification?
No - it is a non-synchronous buck converter requiring an external Schottky diode for freewheeling current path. The datasheet explicitly specifies use of low-VF Schottky diodes (e.g., B290-13-F) and does not provide a low-side driver or control signals for synchronous MOSFETs.
How does frequency foldback improve reliability during startup?
During startup, frequency foldback reduces switching frequency to prevent inductor current runaway when output capacitance is uncharged. By limiting peak current per cycle and extending off-time, it avoids saturation, thermal stress, and potential damage to the internal MOSFET or external diode - especially critical with large output capacitors.
What is the maximum allowable output voltage adjustment range?
The output voltage is adjustable from 0.8V to 52V using an external resistive divider on the FB pin. This range is guaranteed across the full input range (3.8V–55V) and operating temperature (–40°C to +125°C), provided the feedback resistor network maintains ≥10kΩ total resistance to limit leakage-induced error.
Why is MPQ4559DQ-LF-Z marked "Not Recommended for New Designs"?
MPS issued this designation because MPQ4572DQ-LF-Z supersedes it with improved specs (lower RDS(ON), higher input rating, tighter tolerances) and ongoing long-term supply assurance. MPQ4559DQ-LF-Z remains fully functional and supported for legacy production, but new designs should adopt the MPQ4572 for future-proofing.
MPQ4559DQ-LF-Z Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Monolithic Power Systems Inc.
- Series:
- -
- Package/Case:
- 10-VFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3.8V
- Voltage - Input (Max):
- 55V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 52V
- Current - Output:
- 1.5A
- Frequency - Switching:
- Up to 2MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-QFN (3x3)
MPQ4559DQ-LF-Z FAQ
1.How can I place an order for MPQ4559DQ-LF-Z through Aetrix?
Please submit a Request for Quotation (RFQ) for MPQ4559DQ-LF-Z on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MPQ4559DQ-LF-Z reliable?
The price and inventory of MPQ4559DQ-LF-Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MPQ4559DQ-LF-Z is usually 5 days.
3.What payment methods are accepted for MPQ4559DQ-LF-Z?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MPQ4559DQ-LF-Z transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MPQ4559DQ-LF-Z?
MPQ4559DQ-LF-Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MPQ4559DQ-LF-Z order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MPQ4559DQ-LF-Z?
For technical support, including MPQ4559DQ-LF-Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MPQ4559DQ-LF-Z requirements.
6.How does Aetrix verify that MPQ4559DQ-LF-Z is sourced from the original manufacturer or authorized distributors?
All MPQ4559DQ-LF-Z products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MPQ4559DQ-LF-Z meets industry standards.
7.What is the process for return or replacement of MPQ4559DQ-LF-Z?
All MPQ4559DQ-LF-Z units undergo pre-shipment inspection (PSI). If there is an issue with MPQ4559DQ-LF-Z, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MPQ4559DQ-LF-Z part is unused and in its original packaging.
Return procedure for MPQ4559DQ-LF-Z:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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