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Monolithic Power Systems Inc. MPQ2451DG-LF-Z
- Part No.:
- MPQ2451DG-LF-Z
- Manufacturer:
- Monolithic Power Systems Inc.
- Package:
- 6-VDFN Exposed Pad
- Datasheet:
-
MPQ2451DG-LF-Z.pdf
- Description:
- IC REG BUCK ADJ 600MA 6QFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,901
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Product details
Overview
MPQ2451DG-LF-Z from Monolithic Power Systems is an AEC-Q100 Grade 1 qualified, non-synchronous step-down DC/DC converter with integrated 500mΩ high-side MOSFET, delivering up to 0.6A output current at 2MHz fixed switching frequency. It operates across a 3.3V–36V input range, features 130µA quiescent current, internal soft-start, and precision current limit-designed for automotive body electronics and industrial power rails requiring robust thermal performance and wide VIN tolerance.
For engineers reviewing the MPQ2451DG-LF-Z datasheet, MPQ2451DG-LF-Z pinout, MPQ2451DG-LF-Z application, or MPQ2451DG-LF-Z equivalent, key selection criteria include its QFN-6L package thermal resistance (θJA = 80°C/W), 0.794V feedback reference accuracy (±2.5%), pulse-skipping light-load efficiency mode, and bootstrap capacitor charging behavior under high-duty-cycle conditions.
Technical Context
The MPQ2451DG-LF-Z implements current-mode control with a fixed 2MHz oscillator and internal compensation, eliminating external loop components. Its error amplifier compares FB voltage against a trimmed 0.794V reference, driving the COMP node to regulate peak switch current via a transconductance of 3A/V.
Startup uses a 0.5–1ms internal soft-start ramp that overrides the reference until VSS reaches VFB; shutdown is triggered by EN <1.35V, VIN UVLO (2.7–3.29V hysteresis), or junction temperature exceeding 150°C. Bootstrap charging relies on an external BST capacitor between BST and SW pins, regulated to ~5V by an internal PMOS pass device.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.3V to 36V - supports 12V/24V automotive batteries and industrial 24V/36V rails without pre-regulation. |
| Output Current | 0.6A continuous - limited cycle-by-cycle via internal current sense MOSFET; no external sense resistor required. |
| Switching Frequency | 2MHz (±30%) - enables compact 2.2–4.7µH inductors and reduces EMI fundamental below 10MHz. |
| Feedback Reference | 0.794V ±2.5% - sets output voltage via external resistor divider; enables 0.8V–0.9·VIN adjustable or fixed 3.3V/5V options. |
| Quiescent Current | 130µA typical - sustains >10-year battery life in always-on automotive modules (e.g., CAN gateway standby). |
| Shutdown Current | 3µA - ensures minimal leakage during vehicle ignition-off state. |
| Thermal Shutdown | 150°C activation - protects die during overload or poor PCB copper; auto-recovery at ~135°C. |
Pinout & Package
MPQ2451DG-LF-Z is housed in a thermally enhanced 2mm × 2mm QFN-6L package with exposed thermal pad (pin 6), optimized for low θJA (80°C/W) on 4-layer PCBs. Pin 1 is SW; pin 2 is EN; pin 3 is FB; pin 4 is GND; pin 5 is VIN; pin 6 is BST.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (SW) | Switch Node | Drain of internal high-side MOSFET; connects to inductor and freewheeling diode cathode; requires low-inductance layout to minimize ringing. |
| 2 (EN) | Enable Input | Logic-controlled startup/shutdown; 1.35–1.8V threshold; floating disables IC; 0V forces 3µA shutdown mode. |
| 3 (FB) | Feedback Input | Senses output voltage via resistive divider; referenced to 0.794V internal bandgap; sets regulation point and loop gain. |
| 4 (GND) | Power Ground | Return path for output capacitor, bootstrap capacitor, and internal regulator; must be connected directly to thermal pad. |
| 5 (VIN) | Input Supply | Powers internal regulator and gate driver; requires ≥4.7µF ceramic decoupling placed within 2mm of pin. |
| 6 (BST) | Bootstrap Supply | Provides floating gate drive for high-side MOSFET; requires 33pF ceramic capacitor to SW pin for charge recycling. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 500mΩ High-Side MOSFET | Eliminates external switch and driver; reduces BOM count and layout area while maintaining 90%+ efficiency at 0.6A. |
| AEC-Q100 Grade 1 Qualification | Validated for -40°C to +125°C ambient operation - meets automotive reliability requirements for engine bay and chassis modules. |
| Frequency Fold-Back at Startup | Prevents inductor current runaway during soft-start by temporarily lowering fSW - avoids saturation and overshoot. |
| Internal Soft-Start (0.5–1ms) | Controls output voltage ramp rate to prevent inrush into downstream capacitors and avoid false overcurrent triggering. |
| Ceramic-Capacitor Stable | No external compensation needed - supports low-ESR ceramic output caps (≥10µF) without oscillation risk. |
Applications
| Automotive Body Control Module (BCM) | Industrial PLC I/O Power Rail |
|---|---|
Use Scenario: Powers microcontroller, CAN transceiver, and sensor interface circuitry in door module with 12V battery input. IC Role / Device Role / Timing Role: Primary 5V/0.6A buck regulator; provides clean, regulated supply independent of battery voltage sag during cranking (6V–16V). Use Value: 130µA IQ extends sleep-mode battery life; AEC-Q100 qualification ensures operation at 105°C under dashboard heat. |
Use Scenario: Generates isolated 3.3V rail for digital logic and ADC reference in DIN-rail mounted programmable logic controller. IC Role / Device Role / Timing Role: Secondary step-down stage after front-end 48V-to-12V conversion; delivers stable 3.3V at full load across 36V max input. Use Value: 2MHz switching allows small 3.3µH inductor; QFN-6L package enables dense board layout in space-constrained enclosures. |
| Battery-Powered Telematics Unit | Distributed Automotive Lighting Driver |
Use Scenario: Supplies 5V to GPS/GSM modem and MCU in fleet tracking device powered by Li-ion pack (3.6V–4.2V nominal). IC Role / Device Role / Timing Role: Wide-input buck converter enabling direct battery connection without LDO pre-regulator; handles cold-cranking dips to 3.3V. Use Value: 3µA shutdown current preserves battery during multi-week idle periods; internal current limit prevents over-discharge damage. |
Use Scenario: Powers LED driver ICs in adaptive front-lighting system (AFS) with 24V vehicle supply and PWM dimming control. IC Role / Device Role / Timing Role: Local 5V rail generator for LED controller logic and communication interface; withstands load-dump transients up to 36V. Use Value: 36V absolute max rating absorbs ISO 7637-2 Pulse 5a; thermal shutdown prevents failure during prolonged high-brightness operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MPQ2451DG-AEC1 | Same silicon, identical electrical specs; differs only in top marking (V7 vs. AML) and AEC-Q100 certification documentation level. | No functional difference; used interchangeably in production where full AEC-Q100 test reports are required. | Select MPQ2451DG-LF-Z for RoHS-compliant tape-and-reel delivery; MPQ2451DG-AEC1 when certified test data submission is mandatory. |
| MPQ2451GG-5 | Fixed 5V output version (no FB divider); same QFN-6L package, but top marking BP and different enable threshold (1.5V typ). | Reduces BOM count in 5V-only designs but eliminates output adjustability; not suitable for 3.3V or variable-VOUT systems. | Choose MPQ2451GG-5 only if fixed 5V is sufficient and layout space for FB resistors must be eliminated. |
Compared with MPQ2451DG-LF-Z, MPQ2451DG-AEC1 offers identical performance with formal AEC-Q100 reporting, while MPQ2451GG-5 trades flexibility for reduced component count in fixed-output applications-neither provides higher current or wider VIN than the base part.
Availability
MPQ2451DG-LF-Z is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC power rails, and battery-powered telematics requiring stable component supply, AEC-Q100 compliance, and QFN-6L thermal performance.
Supply support for MPQ2451DG-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-efficiency analog and power ICs, with design centers in the US, China, and Taiwan, and manufacturing partners in Asia.
The MPQ2451 belongs to MPS's automotive-grade DC/DC converter product line, engineered specifically for harsh-environment applications demanding extended temperature operation, transient immunity, and long-term reliability in safety-critical subsystems.
FAQ
What is the maximum recommended PCB copper area for the thermal pad of MPQ2451DG-LF-Z?
The QFN-6L thermal pad (pin 6) must be soldered to a minimum 25mm² exposed copper area on the PCB's inner layer, connected via ≥4 thermal vias (0.3mm diameter) to internal ground planes. This achieves the specified θJA = 80°C/W on a 4-layer board per JESD51-7; reducing copper area increases junction temperature linearly.
Can MPQ2451DG-LF-Z operate with a 2.5V input voltage?
No. The absolute minimum operating input voltage is 3.3V per datasheet specifications. At 2.5V, the internal 2.6V regulator cannot sustain bias, causing UVLO lockout and preventing startup. For sub-3.3V inputs, a pre-regulator or alternative converter like MPQ4420A is required.
Is an external bootstrap diode necessary for reliable operation?
An external bootstrap diode (e.g., BAT54) is recommended only when VIN ≤ 5V and VOUT > 3.3V, or when duty cycle exceeds 65% (VOUT/VIN > 0.65). Under standard 12V→5V operation, the internal bootstrap regulator and 33pF BST capacitor provide sufficient gate drive without added components.
How does pulse-skipping mode affect output voltage ripple?
In pulse-skipping mode, the MPQ2451DG-LF-Z reduces switching frequency dynamically, increasing low-frequency ripple amplitude (10–100kHz range) but lowering RMS ripple energy. Output capacitor ESR dominates ripple magnitude; ceramic caps with <10mΩ ESR keep peak-to-peak ripple below 20mV even at 100µA load.
What is the minimum output capacitor value for stable 5V operation?
For 5V output with 3.3µH inductor and 2MHz switching, the minimum recommended output capacitance is 10µF ceramic (X5R/X7R, 10V rating). Lower values risk loop instability and excessive ripple; using <4.7µF may cause audible switching noise and marginal phase margin below 45°.
Does MPQ2451DG-LF-Z support synchronous rectification?
No. The MPQ2451DG-LF-Z is a non-synchronous buck converter with an integrated high-side MOSFET and external Schottky freewheeling diode. It lacks a low-side driver or synchronous control logic; synchronous alternatives include MPQ4420A or MPQ4470.
How is the current limit threshold set internally?
The current limit is set by an internal current-sense MOSFET and comparator with a fixed 0.65A–1A trip range (typ. 0.8A at 25°C). No external resistor adjusts this threshold; it scales with temperature and is factory-trimmed - enabling precise cycle-by-cycle protection without sensing resistor losses.
MPQ2451DG-LF-Z Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Monolithic Power Systems Inc.
- Series:
- -
- Package/Case:
- 6-VDFN 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):
- 3.3V
- Voltage - Input (Max):
- 36V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 32.4V
- Current - Output:
- 600mA
- Frequency - Switching:
- 2MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 6-QFN (2x2)
MPQ2451DG-LF-Z FAQ
1.How can I place an order for MPQ2451DG-LF-Z through Aetrix?
Please submit a Request for Quotation (RFQ) for MPQ2451DG-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 MPQ2451DG-LF-Z reliable?
The price and inventory of MPQ2451DG-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 MPQ2451DG-LF-Z is usually 5 days.
3.What payment methods are accepted for MPQ2451DG-LF-Z?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MPQ2451DG-LF-Z transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MPQ2451DG-LF-Z?
MPQ2451DG-LF-Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MPQ2451DG-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 MPQ2451DG-LF-Z?
For technical support, including MPQ2451DG-LF-Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MPQ2451DG-LF-Z requirements.
6.How does Aetrix verify that MPQ2451DG-LF-Z is sourced from the original manufacturer or authorized distributors?
All MPQ2451DG-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 MPQ2451DG-LF-Z meets industry standards.
7.What is the process for return or replacement of MPQ2451DG-LF-Z?
All MPQ2451DG-LF-Z units undergo pre-shipment inspection (PSI). If there is an issue with MPQ2451DG-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 MPQ2451DG-LF-Z part is unused and in its original packaging.
Return procedure for MPQ2451DG-LF-Z:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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