My Inquiry
My Account
Monolithic Power Systems Inc. MP28251GD-Z
- Part No.:
- MP28251GD-Z
- Manufacturer:
- Monolithic Power Systems Inc.
- Package:
- 14-PowerVFQFN
- Datasheet:
-
MP28251GD-Z.pdf
- Description:
- IC REG BUCK ADJ 4A 14QFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,947
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MP28251GD-Z from Monolithic Power Systems is a synchronous step-down DC-DC converter with integrated 60 mΩ high-side and 30 mΩ low-side MOSFETs, delivering up to 4A continuous output current across a 4.75V–20V input range. It features programmable switching frequency (400–600 kHz typical), external soft-start, and full protection including over-current and thermal shutdown. Used in DSL/cable modems and set-top boxes for compact, efficient 3.3V/5V local power rails.
For engineers reviewing the MP28251GD-Z datasheet, MP28251GD-Z pinout, MP28251GD-Z application, or MP28251GD-Z equivalent, key selection criteria include its 2×3 mm QFN14 package, current-mode control architecture, 0.815V feedback reference, EN delay timing via external capacitor, and compatibility with external clock synchronization from 300 kHz to 2 MHz.
Technical Context
The MP28251 operates in fixed-frequency peak-current-mode control with an internal 5V bias regulator powered from VIN. Its error amplifier compares FB voltage against a precise 0.815V reference and drives COMP to regulate inductor current via PWM duty cycle.
It supports three operational modes: continuous conduction mode (CCM), pulse-skipping mode (PSM), and discontinuous conduction mode (DCM), selected via the LPM pin. Bootstrap charging uses an internal floating driver with UVLO (2.2V rising threshold) and external BST capacitor between SW and BST pins.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.75V to 20V - supports wide industrial and broadband power rails without pre-regulation |
| Output Current | 4A continuous - sufficient for powering SoCs, FPGAs, and multi-rail subsystems in networking equipment |
| Feedback Reference | 0.815V ±15mV - enables accurate output voltage setting down to 0.8V with minimal resistor divider error |
| Switching Frequency | 400–600 kHz (RFREQ=30.1kΩ) - balances efficiency, size, and EMI for mid-power applications |
| HS/LS RDS(on) | 60 mΩ / 30 mΩ - reduces conduction loss and thermal stress at full load, enabling compact thermal design |
| Soft-Start Current | 8 μA - sets linear ramp time with external capacitor; e.g., 22 nF yields ~2.3 ms soft-start duration |
| Thermal Shutdown | 150°C with 30°C hysteresis - protects die during overload or poor PCB heatsinking; auto-recovery at ~120°C |
Pinout & Package
MP28251GD-Z is housed in a thermally enhanced 2 mm × 3 mm, 14-pin QFN package with exposed thermal pad (pin 15 not used; pins 1,12,13,14 are GND). The package supports high-current routing and efficient PCB heat dissipation via multiple GND vias.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 12, 13, 14 | GND | Power and signal ground return paths; must connect to large copper pour for thermal and EMI performance |
| 2, 11 | SW | Switch node - high di/dt path requiring short, wide traces and tight layout to minimize ringing and EMI |
| 3, 15 | IN | Main input supply (4.75–20V); requires local 22 µF ceramic decoupling near IN/GND pins |
| 4 | EN | Enable control with 2.3 µA internal pull-up; capacitor-to-GND adds programmable startup delay |
| 5 | LPM | Low-power mode select - logic-high enables PSM/DCM; grounded forces CCM operation |
| 6 | FB | Feedback input referenced to 0.815V - connects to resistor divider tap for output voltage programming |
| 7 | SS | Soft-start node - 8 µA current source charges external capacitor to control output voltage ramp rate |
| 8 | FREQ/SYNC | Frequency programming or external clock sync input - accepts 300 kHz–2 MHz square wave or resistor-set oscillator |
| 9 | VCC | Internal 5V bias rail output - requires 0.1 µF ceramic capacitor placed adjacent to pin for noise immunity |
| 10 | BST | Bootstrap supply for high-side gate driver - requires 0.1–1 µF capacitor between BST and SW pins |
Key Features
| Feature | Design Value |
|---|---|
| Integrated Power Stage | 60 mΩ HS + 30 mΩ LS MOSFETs eliminate external switch losses and simplify BOM |
| Programmable Frequency | Resistor- or clock-synchronized operation from 300 kHz to 2 MHz enables EMI tuning and inductor optimization |
| External Soft-Start | Capacitor-programmable ramp prevents inrush current and output overshoot during power-up |
| Multi-Mode Efficiency Control | LPM pin selects between CCM (high-load), PSM, or DCM (light-load) to maintain >85% efficiency down to 10 mA |
| Robust Protection Suite | Hiccup-mode OCP and thermal shutdown with auto-recovery ensure safe operation under fault or overload conditions |
Applications
| DSL Modem Power Supply | Cable Modem Core Rail |
|---|---|
|
Use Scenario: Provides stable 3.3V/4A power to DSL line interface ICs and PHY processors in residential gateways. IC Role / Device Role / Timing Role: Primary buck regulator converting 12V adapter input to low-noise digital core rail. Use Value: High efficiency (>92% at 2A) and small 2×3 mm footprint reduce board area and thermal management complexity. |
Use Scenario: Generates 5V/3A for DOCSIS-compliant cable modem SoCs and RF front-end circuitry. IC Role / Device Role / Timing Role: Main DC-DC converter with SYNC input locked to system clock to suppress beat frequencies. Use Value: Programmable soft-start prevents brownout during hot-plug insertion of cable modules. |
| Set-Top Box AV Processor Rail | Home Gateway Baseband Subsystem |
|
Use Scenario: Supplies clean 1.2V/2A to video decoder ASICs and HDMI transceivers in IPTV set-top boxes. IC Role / Device Role / Timing Role: Secondary buck stage following primary 12V-to-5V conversion; uses FB divider with T-network for low-VOUT accuracy. Use Value: 0.815V reference and tight VFB tolerance (±15 mV) ensure <±1% output regulation under dynamic load steps. |
Use Scenario: Powers baseband processor, memory, and USB PHY in Wi-Fi 6 home gateways with bursty traffic loads. IC Role / Device Role / Timing Role: Adaptive-efficiency regulator using LPM pin to switch between CCM and PSM based on traffic activity. Use Value: Light-load efficiency >87% in PSM extends standby runtime while maintaining fast transient response. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous step-down converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MP2384GQ-P | Higher 6A rating, 2.5V–18V input, 500kHz fixed frequency, no SYNC or LPM pin | Lacks frequency synchronization and low-power mode control; suited for simpler, higher-current designs | Select when needing higher output current and fixed-frequency simplicity outweighs programmability needs |
| RT7297CGJ8F | 4A, 4.5V–18V, 600kHz fixed, integrated compensation, no external soft-start or SYNC | No programmable soft-start or external clock sync; lower BOM count but less flexibility in EMI-sensitive systems | Prefer for cost-sensitive consumer applications where layout space is constrained and EMI filtering is handled externally |
Compared with MP28251GD-Z, MP2384GQ-P offers higher current headroom but sacrifices frequency agility and light-load efficiency control, while RT7297CGJ8F reduces component count at the expense of design adaptability for variable load profiles and noise-critical environments.
Availability
MP28251GD-Z is available at Aetrix Electronics and suitable for DSL modems, cable modems, and set-top boxes requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for MP28251GD-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.
The MP28251 belongs to MPS's high-density DC-DC converter product line, engineered for space-constrained broadband and home networking applications demanding high efficiency, small footprint, and robust protection.
FAQ
What is the recommended input capacitor value and type for MP28251GD-Z?
A 22 µF X5R/X7R ceramic capacitor placed directly at the IN and GND pins is recommended. It must handle RMS current ≥2A and be located within 2 mm of the IC. For electrolytic/tantalum use, add a 0.1 µF ceramic in parallel close to the IC to suppress high-frequency noise.
Can MP28251GD-Z operate with a 3.3V input supply?
No. The absolute minimum input voltage is 4.75V per datasheet specifications. Operation below this threshold violates the guaranteed operating conditions and may cause erratic behavior or failure to start due to VCC regulator undervoltage lockout.
How is the output voltage set, and what is the tolerance impact of resistor selection?
Output voltage is set by a resistor divider from VOUT to GND connected to FB, using VFB = 0.815V. With 1% resistors, typical output error is ±0.8% for 3.3V output. For outputs ≤1.2V, a T-network (R1/R2/R8) is recommended to minimize divider current error and improve accuracy.
Does MP28251GD-Z support forced PWM mode, and how is it configured?
No. MP28251GD-Z does not offer forced PWM mode. It operates in CCM by default and automatically transitions to PSM or DCM under light load when LPM is asserted. There is no pin or register to disable light-load efficiency modes.
What is the maximum allowable BST capacitor value, and why is it limited?
The BST capacitor should be 0.1 µF to 1 µF. Larger values increase charge time and risk violating the bootstrap UVLO (2.2V) during startup or high-duty-cycle operation, potentially causing high-side gate drive failure and reduced efficiency.
Is MP28251GD-Z pin-compatible with MP2384GQ-P?
No. MP28251GD-Z uses a 14-pin QFN2×3 with dedicated LPM, SS, and FREQ/SYNC pins, while MP2384GQ-P uses an 8-pin QFN2×2 with different pin assignment and no LPM or SS functionality. Layout and schematic redesign is required for substitution.
What thermal derating applies above 85°C ambient temperature?
At TA = 100°C, maximum continuous output current drops to ~3.2A due to θJA = 70°C/W and TJ(MAX) = 150°C. Derating follows PDMAX = (150 – TA) / 70 W; PCB copper area and airflow significantly affect actual performance.
MP28251GD-Z Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Monolithic Power Systems Inc.
- Series:
- -
- Package/Case:
- 14-PowerVFQFN
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Not For New Designs
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4.75V
- Voltage - Input (Max):
- 20V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 17V
- Current - Output:
- 4A
- Frequency - Switching:
- 500kHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-QFN (2x3)
MP28251GD-Z FAQ
1.How can I place an order for MP28251GD-Z through Aetrix?
Please submit a Request for Quotation (RFQ) for MP28251GD-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 MP28251GD-Z reliable?
The price and inventory of MP28251GD-Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MP28251GD-Z is usually 5 days.
3.What payment methods are accepted for MP28251GD-Z?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MP28251GD-Z transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MP28251GD-Z?
MP28251GD-Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MP28251GD-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 MP28251GD-Z?
For technical support, including MP28251GD-Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MP28251GD-Z requirements.
6.How does Aetrix verify that MP28251GD-Z is sourced from the original manufacturer or authorized distributors?
All MP28251GD-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 MP28251GD-Z meets industry standards.
7.What is the process for return or replacement of MP28251GD-Z?
All MP28251GD-Z units undergo pre-shipment inspection (PSI). If there is an issue with MP28251GD-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 MP28251GD-Z part is unused and in its original packaging.
Return procedure for MP28251GD-Z:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MP28251GD-Z Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
