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Monolithic Power Systems Inc. MPQ4459DQT-LF-Z
- Part No.:
- MPQ4459DQT-LF-Z
- Manufacturer:
- Monolithic Power Systems Inc.
- Package:
- 10-WFDFN Exposed Pad
- Datasheet:
-
MPQ4459DQT-LF-Z.pdf
- Description:
- IC REG BUCK ADJ 1.5A 10TQFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,833
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Product details
Overview
MPQ4459DQT-LF-Z from Monolithic Power Systems is an industrial-grade, non-synchronous step-down DC/DC converter with integrated 150mΩ high-side MOSFET, delivering up to 1.5A output current across a 3.8V–36V input range, programmable 4MHz switching frequency, and 0.8V–30V adjustable output voltage - deployed in automotive power rails and industrial distributed supplies.
For engineers reviewing the MPQ4459DQT-LF-Z datasheet, MPQ4459DQT-LF-Z pinout, MPQ4459DQT-LF-Z application, or MPQ4459DQT-LF-Z equivalent, key selection criteria include quiescent current (120µA), thermal shutdown threshold (150°C), frequency foldback behavior, and bootstrap capacitor charging constraints in high-duty-cycle operation.
Technical Context
The MPQ4459DQT-LF-Z implements peak current-mode control with internal 0.8V reference and transconductance error amplifier (GCS = 4.7 A/V, AEA = 200 V/V), enabling fast transient response and stable loop compensation via external R-C network on COMP pin. Its oscillator uses resistor-programmed frequency (RFREQ) with ±20% tolerance at 4MHz (RFREQ = 18kΩ).
It integrates UVLO (3.0V rising / 2.6V falling), precision enable logic (1.5V rising / 1.2V falling threshold), internal soft-start (1.5ms ramp), and thermal shutdown with 15°C hysteresis. The floating high-side driver relies on BST–SW bootstrap capacitor charged during SW low phase, requiring ≥2.2V UVLO margin and sufficient VIN–VOUT headroom.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.8V to 36V - supports 12V/24V automotive batteries and industrial 24V/36V rails without pre-regulation. |
| Output Current | 1.5A continuous - limited by internal 150mΩ MOSFET RDS(ON) and thermal design (θJA = 50°C/W in TQFN10). |
| Switching Frequency | Up to 4MHz (programmable via RFREQ) - enables compact LC filtering and avoids AM band EMI (0.53–1.7 MHz). |
| Quiescent Current | 120µA - sustains >1-year battery life in always-on industrial sensors with 100mAh coin cell. |
| Feedback Voltage | 0.8V ±2.5% - sets output accuracy; allows 0.8V–30V regulation using standard resistor divider (e.g., 40.2kΩ + 127kΩ for 3.3V). |
| Current Limit | 2.5A typical - cycle-by-cycle overcurrent protection prevents inductor saturation during short-circuit or startup. |
| Operating Temp | –40°C to +125°C junction - qualified for under-hood automotive and factory-floor industrial environments. |
Pinout & Package
MPQ4459DQT-LF-Z is housed in a thermally enhanced 10-pin 3mm × 3mm TQFN package with exposed pad (EP) for PCB heat sinking. Pin numbering follows top-view layout with EP electrically connected to GND.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2 SW | Switch Node | Drain of internal high-side MOSFET; connects to inductor and Schottky diode cathode - requires low-inductance routing to minimize ringing. |
| 3 EN | Enable Input | Positive-logic control: >1.5V enables, <1.2V disables; internal 1µA pull-up allows floating-enable operation. |
| 4 COMP | Compensation Node | Error amplifier output; external RC network (e.g., 68.1kΩ + 220pF) sets loop stability and transient response. |
| 5 FB | Feedback Input | Senses divided output voltage; compared to 0.8V internal reference to regulate VOUT. |
| 6 GND | Power Ground | Main return path for switch current and control circuitry; must tie to EP and output capacitor ground with minimal impedance. |
| 7 FREQ | Frequency Set | Connects external resistor to GND (e.g., 18kΩ → 4MHz); open or short causes undefined frequency or failure. |
| 8, 9 VIN | Input Supply | Primary power input (3.8–36V); requires local 100nF ceramic decoupling close to pins to suppress switching noise. |
| 10 BST | Bootstrap Supply | Charges internal high-side gate driver; requires 100nF ceramic capacitor between BST and SW to sustain gate drive above VIN. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 150mΩ High-Side MOSFET | Eliminates external switch and driver, reducing BOM count and board area in space-constrained modules. |
| 120µA Quiescent Current | Enables direct connection to vehicle battery without auxiliary LDO, preserving runtime in always-on telematics units. |
| Programmable 4MHz Switching | Permits use of sub-3mm inductors (e.g., 2.2µH) and 0805/0603 ceramics, cutting solution size by >40% vs. 500kHz converters. |
| Precision Current Limit (No Sense Resistor) | Uses internal current-sense MOSFET - avoids 1–2% efficiency loss and layout sensitivity of external RSENSE. |
| Ceramic Capacitor Stable | Operates with zero-ESR MLCCs on input/output - removes need for bulk tantalum/electrolytic, improving reliability and temperature range. |
| Internal Soft-Start (1.5ms) | Prevents output overshoot and inrush current into downstream loads (e.g., FPGA core rails or ADC references). |
Applications
| Automotive Body Control Module | Industrial PLC I/O Power |
|---|---|
|
Use Scenario: Powering microcontroller, CAN transceiver, and sensor interface circuits in door module or lighting controller. IC Role / Device Role / Timing Role: Primary 5V/3.3V point-of-load regulator converting 12V battery to stable logic rail with load dump immunity. Use Value: 36V max input withstands ISO 7637-2 pulse 5a (±60V); 4MHz switching avoids interference with AM radio band in cabin electronics. |
Use Scenario: Generating isolated 24V-to-5V/12V rails for analog input conditioning and digital isolation in modular I/O cards. IC Role / Device Role / Timing Role: Non-isolated buck stage supplying isolated DC/DC controllers and signal chain components. Use Value: –40°C to +125°C operation ensures reliability in uncooled control cabinets; 1.5A output supports multiple isolated channels per module. |
| Battery-Powered Test Equipment | Distributed Telecom Power |
|
Use Scenario: Portable multimeter or handheld oscilloscope requiring ultra-low standby power and wide input range from Li-ion or alkaline packs. IC Role / Device Role / Timing Role: Main system regulator managing battery-to-3.3V conversion with dynamic load steps (display backlight, ADC sampling). Use Value: 120µA IQ extends 2000mAh battery life to >1000 hours in sleep mode; programmable frequency optimizes efficiency across 3.0–4.2V battery discharge curve. |
Use Scenario: Remote radio unit (RRU) power management where 48V backplane feeds multiple 5V/12V subsystems in outdoor base stations. IC Role / Device Role / Timing Role: Secondary buck converter stepping down intermediate 24V rail to processor and FPGA core voltages. Use Value: 4MHz operation reduces filter size in constrained RF enclosure; thermal shutdown protects against ambient +70°C derating in sealed enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MPQ4423AGQ-A | Lower 2.5A rating, fixed 2.2MHz frequency, no FREQ pin - lacks programmability and higher current headroom. | Targeted at cost-sensitive consumer power; not rated for full industrial temp range (only –20°C to +85°C). | Select when fixed-frequency design simplifies EMI filtering and 2.5A peak suffices for burst loads. |
| LM61480QRNXTQ1 | Automotive AEC-Q100 Grade 1, 3.5A output, integrated BOOT diode - eliminates external Schottky but increases package size (12-pin WQFN). | Qualified for engine bay deployment; includes spread-spectrum clocking and enhanced fault reporting not present in MPQ4459. | Choose for automotive safety-critical systems requiring AEC-Q100 compliance and diagnostic capability. |
Compared with MPQ4459DQT-LF-Z, MPQ4423AGQ-A trades programmability and industrial temperature for lower cost and simpler layout, while LM61480QRNXTQ1 adds automotive qualification and higher current at the expense of footprint and design flexibility.
Availability
MPQ4459DQT-LF-Z is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC power supplies, battery-powered instrumentation, and distributed telecom systems requiring stable component supply across extended temperature and long product lifecycles.
Supply support for MPQ4459DQT-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 design centers in the US, China, and Taiwan, and global manufacturing partnerships.
The MPQ4459 belongs to MPS's industrial-grade DC/DC converter product line, engineered for robustness in harsh environments - emphasizing wide VIN range, low IQ, and thermal resilience for automotive and factory automation applications.
FAQ
What is the minimum input voltage required for reliable startup?
The MPQ4459DQT-LF-Z features under-voltage lockout (UVLO) with a rising threshold of 3.0V and hysteresis of 0.35V. Reliable startup occurs only when VIN exceeds 3.0V; operation below 2.6V disables the device. This ensures stable biasing of internal regulators before enabling the power stage.
Can the MPQ4459DQT-LF-Z operate without an external bootstrap capacitor?
No. The BST pin requires a 100nF ceramic capacitor connected between BST and SW to charge the internal high-side gate driver. Omitting it prevents proper gate drive, causing immediate failure to regulate and potential thermal shutdown due to prolonged MOSFET conduction.
How does frequency foldback improve startup reliability?
During startup, frequency foldback reduces switching frequency when output voltage is low, limiting peak inductor current and preventing runaway conditions. This avoids excessive current stress on the internal MOSFET and output rectifier before feedback loop stabilization.
Is the MPQ4459DQT-LF-Z RoHS and REACH compliant?
Yes. The "-LF" suffix denotes lead-free, RoHS-compliant packaging per Directive 2011/65/EU. MPS confirms full REACH SVHC compliance and provides material declarations upon request through authorized distributors.
What is the maximum recommended output capacitance for stability?
The MPQ4459DQT-LF-Z supports ceramic, tantalum, and low-ESR electrolytic capacitors. For ceramic outputs, stability is maintained up to 100µF; beyond that, additional compensation (e.g., C6 pole) may be needed per Table 4 in the datasheet to counteract ESR-zero effects.
Does the EN pin support logic-level interfacing with 1.8V microcontrollers?
Yes. With a rising threshold of 1.5V and hysteresis of 300mV, the EN pin reliably accepts 1.8V GPIO signals. A 1µA internal pull-up ensures default-enable behavior when left unconnected, simplifying interface with low-voltage MCUs without level-shifting.
How is thermal performance affected by the exposed pad soldering?
The exposed pad (EP) is electrically GND and thermally critical. Full-solder coverage to a 4-layer PCB with ≥4 thermal vias (0.3mm diameter, filled) reduces θJA from 50°C/W to ~35°C/W, enabling full 1.5A output at +85°C ambient without derating.
MPQ4459DQT-LF-Z Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Monolithic Power Systems Inc.
- Series:
- -
- Package/Case:
- 10-WFDFN 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):
- 36V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 30V
- Current - Output:
- 1.5A
- Frequency - Switching:
- Up to 4MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-TQFN (3x3)
MPQ4459DQT-LF-Z FAQ
1.How can I place an order for MPQ4459DQT-LF-Z through Aetrix?
Please submit a Request for Quotation (RFQ) for MPQ4459DQT-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 MPQ4459DQT-LF-Z reliable?
The price and inventory of MPQ4459DQT-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 MPQ4459DQT-LF-Z is usually 5 days.
3.What payment methods are accepted for MPQ4459DQT-LF-Z?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MPQ4459DQT-LF-Z transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MPQ4459DQT-LF-Z?
MPQ4459DQT-LF-Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MPQ4459DQT-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 MPQ4459DQT-LF-Z?
For technical support, including MPQ4459DQT-LF-Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MPQ4459DQT-LF-Z requirements.
6.How does Aetrix verify that MPQ4459DQT-LF-Z is sourced from the original manufacturer or authorized distributors?
All MPQ4459DQT-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 MPQ4459DQT-LF-Z meets industry standards.
7.What is the process for return or replacement of MPQ4459DQT-LF-Z?
All MPQ4459DQT-LF-Z units undergo pre-shipment inspection (PSI). If there is an issue with MPQ4459DQT-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 MPQ4459DQT-LF-Z part is unused and in its original packaging.
Return procedure for MPQ4459DQT-LF-Z:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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