My Inquiry
My Account
Monolithic Power Systems Inc. MP2128DT-LF-Z
- Part No.:
- MP2128DT-LF-Z
- Manufacturer:
- Monolithic Power Systems Inc.
- Package:
- SC-74A, SOT-753
- Datasheet:
-
MP2128DT-LF-Z.pdf
- Description:
- IC REG BUCK ADJ 1A SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:8,142
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MP2128DT-LF-Z from Monolithic Power Systems is a 3MHz synchronous step-down DC/DC converter with integrated high-side PFET and low-side NFET, delivering up to 1A output current from a 2.5V–6V input. It regulates output down to 0.6V with ±2% FB voltage accuracy, features cycle-by-cycle over-current protection, thermal shutdown, and <1µA shutdown current-designed for Li-ion/Li-polymer battery-powered portable electronics.
For engineers reviewing the MP2128DT-LF-Z datasheet, MP2128DT-LF-Z pinout, MP2128DT-LF-Z application, or MP2128DT-LF-Z equivalent, key selection criteria include its 3MHz fixed-frequency current-mode control, SOT23-5 package footprint, 0.6V reference voltage, 1.5A PFET current limit, and dropout operation enabling 100% duty cycle at low VIN.
Technical Context
The MP2128DT-LF-Z implements slope-compensated peak current-mode PWM control with a fixed 3MHz oscillator, enabling fast transient response and stable regulation across 2.5V–6V input while maintaining sub-500ns minimum on-time. Its internal 200mΩ PFET and 150mΩ NFET enable high-efficiency synchronous rectification without external diodes.
It supports 100% duty-cycle operation for ultra-low dropout, uses an internal 0.6V feedback reference with ±2% tolerance over –40°C to +85°C, and incorporates short-circuit protection that reduces switching frequency and current limit during fault conditions-automatically recovering when FB rises above 0.6V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.5V to 6V - supports single-cell Li-ion (2.7–4.2V) and Li-polymer batteries with headroom for USB 5V input. |
| Output Voltage Range | 0.6V to 6V - adjustable via external resistor divider; 0.6V reference enables core supplies for modern microprocessors and DSPs. |
| Switching Frequency | 3MHz (typ.) - enables use of small 1.2µH inductors and 10µF ceramic output capacitors for compact PCB layouts. |
| Max Output Current | 1A continuous - sustained under thermal limits in SOT23-5 package with θJA = 220°C/W at TA = +25°C. |
| FB Reference Voltage | 0.594V (typ.), ±2% over temperature - ensures tight output regulation for sensitive digital loads like SoC cores and memory I/O. |
| Shutdown Current | <1µA - preserves battery life in standby mode for always-on portable devices such as smartwatches and BLE sensors. |
| UVLO Threshold | 2.1V (rising), 250mV hysteresis - prevents erratic startup during battery discharge and ensures clean power-up sequencing. |
Pinout & Package
The MP2128DT-LF-Z is housed in a RoHS-compliant, lead-free 5-pin SOT23 package (1.5mm height), optimized for space-constrained portable designs. Pin 1 is EN, Pin 2 is GND, Pin 3 is SW, Pin 4 is IN, and Pin 5 is FB.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 (EN) | Enable control input | Logic-level interface: >1.6V turns regulator on; <0.4V forces shutdown with <1µA quiescent draw. |
| 2 (GND) | Power ground | Common return path for IN, SW, and FB; must be low-impedance connection to minimize noise coupling into feedback loop. |
| 3 (SW) | Power switch node | Drain connection of internal PFET/NFET; connects directly to inductor; requires tight layout to reduce EMI and switching losses. |
| 4 (IN) | Input supply | Accepts 2.5V–6V; requires ≥4.7µF ceramic bypass capacitor placed adjacent to this pin for high-frequency stability. |
| 5 (FB) | Feedback input | Senses output via resistive divider; regulated at 0.594V ±2%; high-impedance input (<50nA bias) minimizes divider current error. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated synchronous FETs | 200mΩ PFET + 150mΩ NFET eliminates external Schottky diode, improving efficiency by ~5–8% vs. asynchronous designs. |
| Internal soft-start | 100µs ramp time prevents inrush current and output overshoot during startup-critical for powering FPGA or ASIC cores. |
| Cycle-by-cycle current limit | 1.5A PFET current limit with slope compensation prevents subharmonic oscillation at >50% duty cycle and protects against overload. |
| Thermal shutdown with hysteresis | 150°C trip point with 20°C hysteresis ensures safe recovery after overheating without oscillatory cycling. |
| Short-circuit protection | Reduces switching frequency and lowers current limit during output short; auto-resumes regulation once fault clears. |
Applications
| Cellular Phones | Microprocessor Core Supplies |
|---|---|
|
Use Scenario: Powering baseband and application processors in dual-SIM smartphones operating from single Li-ion cells. IC Role / Device Role / Timing Role: Primary buck regulator supplying 1.2V/1.8V core and I/O rails with fast load transient response. Use Value: 3MHz switching enables compact 1.2µH inductor and 10µF ceramic output cap, reducing board area by >30% vs. 1MHz alternatives. |
Use Scenario: Delivering tightly regulated 0.8V–1.2V to ARM Cortex-A series CPU cores in handheld computing devices. IC Role / Device Role / Timing Role: High-PSRR, low-noise DC/DC converter with 0.6V reference and ±2% FB accuracy for dynamic voltage scaling. Use Value: Internal soft-start and cycle-by-cycle current limiting prevent brownout during sudden core wake-up events. |
| PDAs and Smartphones | Digital Still Cameras |
|
Use Scenario: Supplying multiple voltage rails (e.g., 3.3V for display interface, 1.8V for memory) in legacy PDA platforms. IC Role / Device Role / Timing Role: Secondary buck regulator in multi-rail PMIC architecture, enabled/disabled via system controller GPIO. Use Value: <1µA shutdown current extends standby battery life beyond 7 days in always-connected mobile clients. |
Use Scenario: Powering image sensor analog front-end and ISP core in compact digital cameras with flash LED support. IC Role / Device Role / Timing Role: Main camera rail regulator handling pulsed 500mA loads during image capture bursts. Use Value: 100% duty-cycle dropout operation maintains 1.8V output even as battery discharges to 2.5V, avoiding frame loss. |
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 |
|---|---|---|---|
| TPS62231DRYR (TI) | 2.25MHz switching, 0.6V ref, 1A rating, 6-pin WSON package; higher quiescent current (12µA shutdown). | Requires external soft-start capacitor; lacks integrated short-circuit frequency foldback. | Preferred where WSON thermal performance (θJA = 110°C/W) is critical over SOT23 size constraints. |
| RT8059GJ6 (Richtek) | 1.5MHz switching, 0.6V ref, 1A rating, SOT23-6 package; includes power-good flag not present in MP2128. | Slower transient response due to lower frequency; larger inductor required (2.2µH typical). | Chosen when system-level power sequencing requires PG signal for downstream logic enable. |
Compared with TPS62231DRYR and RT8059GJ6, the MP2128DT-LF-Z delivers superior high-frequency efficiency in minimal area, trades off PG signaling and ultra-low-noise operation for cost-sensitive, space-limited portable designs requiring rapid load-step response and deep battery discharge support.
Availability
MP2128DT-LF-Z is available at Aetrix Electronics and suitable for cellular phones, microprocessor core supplies, and portable media players requiring stable component supply with full RoHS compliance and tape-and-reel packaging.
Supply support for MP2128DT-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, headquartered in California and serving global power management markets since 1997.
The MP2128 belongs to MPS's high-frequency synchronous buck converter product line, engineered specifically for battery-powered portable electronics demanding small size, high efficiency, and robust protection at sub-1A load levels.
FAQ
What is the maximum recommended PCB copper area for thermal relief with MP2128DT-LF-Z in SOT23-5?
For reliable 1A operation at +85°C ambient, Monolithic Power recommends a minimum 120mm² exposed copper pad connected to Pin 2 (GND) with ≥4 thermal vias (0.3mm diameter) to inner ground planes. This achieves effective θJA ≈ 180°C/W, preventing thermal shutdown under full load.
Can MP2128DT-LF-Z operate with input voltage below 2.5V?
No. The absolute minimum input voltage is 2.5V per datasheet specifications. Below this, UVLO prevents startup, and internal bias circuitry cannot sustain regulation. Operation at 2.4V may result in erratic switching or failure to regulate, especially at elevated temperatures.
Is the FB pin internally compensated, or does it require external compensation components?
The MP2128DT-LF-Z uses internal Type II compensation; no external capacitor or resistor is needed on the FB node. The feedback loop is optimized for standard 1.2µH inductors and 10µF ceramic output capacitors-external compensation would destabilize the control loop.
Does MP2128DT-LF-Z support forced PWM mode, or is it strictly constant-frequency current-mode?
It operates exclusively in constant-frequency peak current-mode control with slope compensation. There is no skip-mode or forced-PWM selection pin or register; frequency remains fixed at ~3MHz across all load conditions from 1mA to 1A.
What is the minimum output capacitor ESR requirement for stable operation?
No minimum ESR is required-the MP2128DT-LF-Z is optimized for low-ESR ceramic capacitors (e.g., X5R/X7R). Using high-ESR electrolytics (>50mΩ) causes excessive output ripple and potential instability; 10µF ceramic with ≤5mΩ ESR is the validated design point.
How does the short-circuit protection behave when VOUT is shorted to GND?
Upon short detection, the MP2128DT-LF-Z reduces switching frequency to ~300kHz and lowers the PFET current limit from 1.5A to ~0.5A. Output voltage collapses, but device remains powered and automatically resumes normal regulation within 10ms after short removal and FB recovery to 0.6V.
Can EN pin be driven directly by a 1.8V GPIO without level shifting?
No. The EN threshold is 1.6V (min) for turn-on and 0.4V (max) for turn-off. A 1.8V GPIO meets the high threshold but risks marginal activation if VCC sags or temperature drifts; a dedicated 3.3V enable rail or simple N-MOS level shifter is recommended for robust control.
MP2128DT-LF-Z Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Monolithic Power Systems Inc.
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- 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):
- 2.5V
- Voltage - Input (Max):
- 6V
- Voltage - Output (Min/Fixed):
- 0.6V
- Voltage - Output (Max):
- 6V
- Current - Output:
- 1A
- Frequency - Switching:
- 2.8MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
MP2128DT-LF-Z FAQ
1.How can I place an order for MP2128DT-LF-Z through Aetrix?
Please submit a Request for Quotation (RFQ) for MP2128DT-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 MP2128DT-LF-Z reliable?
The price and inventory of MP2128DT-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 MP2128DT-LF-Z is usually 5 days.
3.What payment methods are accepted for MP2128DT-LF-Z?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MP2128DT-LF-Z transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MP2128DT-LF-Z?
MP2128DT-LF-Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MP2128DT-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 MP2128DT-LF-Z?
For technical support, including MP2128DT-LF-Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MP2128DT-LF-Z requirements.
6.How does Aetrix verify that MP2128DT-LF-Z is sourced from the original manufacturer or authorized distributors?
All MP2128DT-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 MP2128DT-LF-Z meets industry standards.
7.What is the process for return or replacement of MP2128DT-LF-Z?
All MP2128DT-LF-Z units undergo pre-shipment inspection (PSI). If there is an issue with MP2128DT-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 MP2128DT-LF-Z part is unused and in its original packaging.
Return procedure for MP2128DT-LF-Z:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MP2128DT-LF-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…
