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Monolithic Power Systems Inc. MPQ4459DQT-LF-P
- Part No.:
- MPQ4459DQT-LF-P
- Manufacturer:
- Monolithic Power Systems Inc.
- Package:
- 10-WFDFN Exposed Pad
- Datasheet:
-
MPQ4459DQT-LF-P.pdf
- Description:
- IC REG BUCK ADJ 1.5A 10TQFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,330
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Product details
Overview
MPQ4459DQT-LF-P 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. It operates at up to 4MHz switching frequency, features 120µA quiescent current, and supports adjustable output voltage from 0.8V to 30V - optimized for automotive power rails, battery-powered industrial sensors, and high-voltage distributed systems.
For engineers reviewing the MPQ4459DQT-LF-P datasheet, MPQ4459DQT-LF-P pinout, MPQ4459DQT-LF-P application, or MPQ4459DQT-LF-P equivalent, key selection criteria include programmable 4MHz operation for EMI-sensitive AM/ADSL environments, internal soft-start and thermal shutdown for robust startup/fault handling, precision current limit without external sense resistor, and ceramic-capacitor stability in compact 3mm × 3mm TQFN-10 packaging.
Technical Context
The MPQ4459DQT-LF-P implements current-mode control with a transconductance error amplifier (GCS = 4.7 A/V) and cycle-by-cycle peak current limiting. Its oscillator frequency is externally set via a resistor on the FREQ pin, enabling precise 1.2MHz–4MHz tuning - critical for avoiding interference bands while maintaining loop stability.
It integrates a bootstrap driver for the high-side MOSFET, requiring an external BST–SW capacitor; internal UVLO (3.0V rising, 2.6V falling) and thermal shutdown (150°C trip, 135°C hysteresis) ensure safe operation across –40°C to +125°C junction temperature. The COMP pin serves as the error amplifier output for full-loop compensation using R/C networks.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.8V to 36V - supports direct connection to 12V/24V automotive batteries and industrial 24V/36V rails without pre-regulation. |
| Output Current | 1.5A continuous - sufficient for powering microcontrollers, CAN transceivers, and analog front-ends in embedded systems. |
| Switching Frequency | Up to 4MHz - enables use of small inductors (e.g., 2.2µH) and avoids AM radio band (0.53–1.71MHz) and ADSL upstream band (25.8–138kHz). |
| Quiescent Current | 120µA - extends battery life in always-on IoT nodes and remote sensors operating from Li-ion or coin cells. |
| Feedback Reference | 0.8V ±2.5% - allows accurate output regulation down to 0.8V and up to 30V using standard resistor dividers. |
| Internal MOSFET RDS(ON) | 150mΩ - minimizes conduction loss at 1.5A, supporting >90% efficiency at 5V/1.5A with 12V input. |
| Thermal Shutdown | 150°C with 15°C hysteresis - provides self-protecting operation under overload or poor PCB thermal design. |
Pinout & Package
MPQ4459DQT-LF-P is housed in a thermally enhanced 10-pin 3mm × 3mm TQFN package with exposed thermal pad on the underside for efficient heat dissipation in space-constrained industrial PCBs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2 SW | Switch Node | High-current output of internal MOSFET; connects directly to inductor and Schottky diode cathode - requires low-inductance layout to suppress ringing. |
| 3 EN | Enable Input | Positive-logic enable with 1.5V rising threshold and 1.2V falling threshold; internally pulled up to ~3V when floating. |
| 4 COMP | Compensation Node | Error amplifier output; accepts RC network to set pole-zero locations for stable current-mode control loop. |
| 5 FB | Feedback Input | Senses divided output voltage; compared to internal 0.8V reference to regulate VOUT - bias current <1µA minimizes divider error. |
| 6 GND | Power Ground | Reference for all internal circuitry; must be connected near output capacitor to avoid noise coupling into feedback path. |
| 7 FREQ | Frequency Set | Connects external resistor to GND to program fS from 0.2MHz to 4MHz - 45kΩ yields nominal 4MHz operation. |
| 8, 9 VIN | Input Supply | Primary power input for control circuitry and high-side driver; requires local 1µF ceramic decoupling close to pins. |
| 10 BST | Bootstrap Supply | Provides gate drive voltage for high-side MOSFET; requires 0.1µF ceramic capacitor between BST and SW pins. |
Key Features
| Feature | Design Value |
|---|---|
| Industrial Temperature Range | Guaranteed operation from –40°C to +125°C junction temperature - suitable for under-hood automotive and factory-floor applications. |
| Ceramic Capacitor Stability | Stable with zero-ESR ceramic output capacitors - eliminates need for tantalum/electrolytic parts, improving reliability and lifetime. |
| Precision Current Limit | 2.5A typical cycle-by-cycle limit without external sense resistor - simplifies BOM and improves accuracy vs. discrete sensing. |
| Internal Soft-Start | 1.5ms built-in ramp - prevents output overshoot during power-up and reduces inrush stress on input capacitors and diodes. |
| Frequency Foldback | Reduces fS during startup and overload - prevents inductor saturation and maintains control loop stability under transient conditions. |
Applications
| Automotive Body Control Module | Industrial PLC I/O Power |
|---|---|
|
Use Scenario: Powering 3.3V logic and CAN transceivers in door modules or lighting controllers supplied from 12V battery with cold-crank dips to 3.8V. IC Role / Device Role / Timing Role: Primary step-down regulator providing regulated 3.3V rail with fast load transient response and fault tolerance during load dump events. Use Value: 4MHz operation avoids interference with vehicle AM/FM receivers; 36V absolute max rating withstands ISO 7637-2 pulse 5a (75V/100ms). |
Use Scenario: Generating 5V/1.5A for digital I/O isolation and sensor interface circuits in DIN-rail mounted programmable logic controllers. IC Role / Device Role / Timing Role: High-efficiency, wide-input buck converter replacing linear regulators to reduce thermal load in enclosed enclosures. Use Value: 120µA quiescent current enables low-power standby modes; TQFN-10 package fits dense PCB layouts with minimal footprint. |
| Battery-Powered Telematics Unit | Distributed Telecom Power |
|
Use Scenario: Converting 8.4V LiPo (2S) to 1.8V for RF SoC and 3.3V for MCU in GPS/GSM trackers with multi-year battery life requirements. IC Role / Device Role / Timing Role: Dual-rail power source with independent feedback paths (via resistor dividers), leveraging ultra-low IQ for extended sleep cycles. Use Value: 0.8V reference enables precise low-VOUT regulation; internal current limit protects against shorted antenna or SIM card faults. |
Use Scenario: Point-of-load conversion in remote radio units (RRUs) where 24V/48V backplane supplies must be stepped down to 5V/3.3V for FPGA and ADCs. IC Role / Device Role / Timing Role: Compact, high-frequency buck regulator minimizing filter component size and board area in thermally constrained RF enclosures. Use Value: 4MHz switching allows sub-3mm inductors; thermal shutdown ensures safe operation during ambient temperature excursions above 85°C. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MPQ4423AGU-AEC1-P | AEC-Q100 qualified, 2.5A output, 2.2MHz fixed frequency, 100mΩ RDS(ON), same 3.8–36V input. | Designed for automotive safety-critical systems requiring qualification; lacks programmable frequency and has higher IQ (250µA). | Select when AEC-Q100 compliance is mandatory and higher current headroom is needed; not drop-in due to different pinout and frequency behavior. |
| LM61480RQR | TI part, 8A output, 2.1MHz fixed frequency, 12mΩ RDS(ON), 1.5µA IQ in shutdown, but 150µA operating IQ. | Higher power tier targeting server/industrial PSU; larger 16-pin WQFN package, no FREQ pin, requires external current sense. | Choose for >3A loads or where TI ecosystem support is preferred; incompatible pinout and compensation architecture limit interchangeability. |
Compared with MPQ4459DQT-LF-P, the MPQ4423AGU-AEC1-P offers automotive qualification and higher current but sacrifices frequency flexibility and quiescent efficiency, while the LM61480RQR delivers much higher output capability at the cost of size, complexity, and lack of programmability - making MPQ4459DQT-LF-P optimal for compact, EMI-aware 1.5A industrial and automotive auxiliary rails.
Availability
MPQ4459DQT-LF-P is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC power supplies, battery-powered telematics, and distributed telecom point-of-load applications requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.
Supply support for MPQ4459DQT-LF-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 core expertise in DC/DC conversion, motor drivers, and LED lighting controllers.
The MPQ4459 belongs to MPS's industrial-grade buck converter product line, designed specifically for ruggedized power delivery in automotive, industrial automation, and infrastructure equipment where wide input range, high frequency, and thermal resilience are essential.
FAQ
What is the minimum recommended input voltage for reliable startup?
The MPQ4459DQT-LF-P has a guaranteed UVLO rising threshold of 3.0V, but stable operation begins at 3.8V per datasheet specifications. Below 3.8V, output regulation may degrade or fail to initiate due to insufficient headroom for internal regulators and bootstrap charging - design for ≥4.0V minimum input in production systems.
Can the MPQ4459DQT-LF-P operate without an external bootstrap diode?
Yes - the MPQ4459DQT-LF-P uses an internal bootstrap regulator that charges the BST–SW capacitor directly from VIN during low-duty-cycle operation. An external diode is only required if duty cycle exceeds ~85% or if VIN approaches VOUT, where internal charging becomes marginal; most designs at ≤5V output and ≤12V input function reliably without it.
How does the frequency foldback feature behave during overload?
During overload or short-circuit, the MPQ4459DQT-LF-P automatically reduces switching frequency to prevent inductor current runaway and thermal runaway. This foldback lowers fS below the programmed value - e.g., from 4MHz to ~1MHz - extending off-time to limit peak switch current while maintaining regulation attempt until thermal shutdown activates.
Is the 0.8V feedback reference trimmed over temperature?
Yes - the internal 0.8V reference has ±2.5% tolerance over –40°C to +125°C junction temperature, as confirmed by electrical characteristics table. This ensures stable output voltage regulation across full industrial temperature range without external calibration.
What is the maximum allowable output capacitance for stable operation?
No hard upper limit exists, but stability depends on ESR and zero placement. With ceramic capacitors (low ESR), stability is maintained up to 100µF using standard compensation (e.g., 100pF + 105kΩ). For >100µF or high-ESR electrolytics, add a third pole (C6) per Table 4 to counteract ESR zero - verified in MPS AN-107 application note.
Does the EN pin support partial enable functionality?
No - the EN pin is strictly binary: voltages ≥1.5V enable full operation; voltages ≤1.2V force complete shutdown with 12µA quiescent current. Between 1.2V and 1.5V, the device remains latched in shutdown mode with slightly elevated IQ (~18µA), but no intermediate states or analog control are supported.
What layout guidance is critical for EMI performance at 4MHz?
Minimize SW node copper area and keep SW–diode–inductor loop <3mm²; place input capacitor <2mm from VIN/GND pins; use solid ground plane under IC; avoid routing sensitive traces (FB, COMP) near SW or inductors; and ensure BST capacitor is placed directly between BST and SW pins with shortest possible traces.
MPQ4459DQT-LF-P 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-P FAQ
1.How can I place an order for MPQ4459DQT-LF-P through Aetrix?
Please submit a Request for Quotation (RFQ) for MPQ4459DQT-LF-P 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-P reliable?
The price and inventory of MPQ4459DQT-LF-P 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-P is usually 5 days.
3.What payment methods are accepted for MPQ4459DQT-LF-P?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MPQ4459DQT-LF-P transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MPQ4459DQT-LF-P?
MPQ4459DQT-LF-P orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MPQ4459DQT-LF-P 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-P?
For technical support, including MPQ4459DQT-LF-P datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MPQ4459DQT-LF-P requirements.
6.How does Aetrix verify that MPQ4459DQT-LF-P is sourced from the original manufacturer or authorized distributors?
All MPQ4459DQT-LF-P 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-P meets industry standards.
7.What is the process for return or replacement of MPQ4459DQT-LF-P?
All MPQ4459DQT-LF-P units undergo pre-shipment inspection (PSI). If there is an issue with MPQ4459DQT-LF-P, 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-P part is unused and in its original packaging.
Return procedure for MPQ4459DQT-LF-P:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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