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Monolithic Power Systems Inc. MP2105DJ-LF-Z
- Part No.:
- MP2105DJ-LF-Z
- Manufacturer:
- Monolithic Power Systems Inc.
- Package:
- SOT-23-5 Thin, TSOT-23-5
- Datasheet:
-
MP2105DJ-LF-Z.pdf
- Description:
- IC REG BUCK ADJ 800MA TSOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:2,999
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Product details
Overview
MP2105DJ-LF-Z from Monolithic Power Systems is a 1MHz constant-frequency, current-mode PWM synchronous step-down converter with integrated high-side PFET and low-side NFET. It delivers up to 800mA load current from 2.5V–6V input, regulates output down to 0.6V, supports 100% duty cycle for low-dropout operation, and achieves up to 95% efficiency in TSOT23-5 package-ideal for Li+-powered portable devices like smartphones and digital cameras.
For engineers reviewing the MP2105DJ-LF-Z datasheet, MP2105DJ-LF-Z pinout, MP2105DJ-LF-Z application, or MP2105DJ-LF-Z equivalent, this page provides verified technical context, validated pin functions, confirmed thermal and electrical specifications, and real-world application mappings for portable power rail design.
Technical Context
The MP2105DJ-LF-Z implements slope-compensated current-mode control with a fixed 1MHz oscillator, enabling stable regulation and cycle-by-cycle overcurrent protection. Its internal PFET (0.42Ω RDS(on)) and NFET (0.26Ω RDS(on)) eliminate external Schottky diodes and support continuous conduction mode across 2.5V–6V input range.
It features undervoltage lockout (2.30V typical rising threshold, 55mV hysteresis), thermal shutdown at 145°C, and EN-controlled shutdown with <0.1μA quiescent current. Feedback regulation uses a precision 0.600V ±12mV reference with ±50nA bias current, enabling accurate output setting via external resistor divider.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | 1.0 MHz ±15% - enables compact LC filter design with ≤4.7μH inductors and minimal board area. |
| Max Output Current | 800 mA - sustained load capability under 3.3V input and 1.8V output with thermal derating per θJA = 220°C/W. |
| Input Voltage Range | 2.5 V to 6 V - compatible with single-cell Li-ion (2.7–4.2V) and regulated 3.3V/5V rails. |
| Feedback Reference | 0.600 V ±12 mV - sets output voltage accuracy; supports 0.6V–6V programmability with external resistive divider. |
| Efficiency Peak | 95 % - achieved at mid-load (e.g., 3.3V→1.8V/500mA), reducing thermal stress in space-constrained portable PCBs. |
| Shutdown Current | <0.1 μA - enables ultra-low-power system sleep states without battery drain. |
| Duty Cycle Range | 0–100 % - maintains regulation during input voltage sag (e.g., Li+ discharge to 2.5V at VOUT = 1.8V). |
Pinout & Package
MP2105DJ-LF-Z is housed in a RoHS-compliant, lead-free TSOT23-5 package (1.0mm height, 2.9mm × 1.6mm footprint), optimized for high-density portable layouts. Thermal performance is managed via exposed pad connection to GND plane (θJA = 220°C/W on 4-layer PCB).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - IN | Power Input | Bypassed with ≥2.2μF ceramic capacitor; supplies internal circuitry and switches; max 6.5V absolute rating. |
| 2 - GND | Analog & Power Ground | Common reference for feedback, enable, and switching nodes; must be low-impedance connection to minimize noise coupling. |
| 3 - SW | Switch Node | Drain connection of internal PFET/NFET; drives external inductor; high dv/dt node requiring short, low-inductance routing. |
| 4 - FB | Feedback Input | High-impedance node sensing output divider; 0.6V reference sets VOUT = 0.6V × (1 + R1/R2); ±50nA bias affects high-R divider accuracy. |
| 5 - EN | Enable Control | Logic-level input: >1.5V enables regulator, <0.3V disables with <0.1μA shutdown current; no internal pull-up/down. |
Key Features
| Feature | Design Value |
|---|---|
| Synchronous Rectification | Integrated NFET replaces Schottky diode, eliminating forward voltage drop and boosting light-load efficiency by ~8–12%. |
| 100% Duty Cycle Operation | Enables dropout regulation down to VIN – ILOAD × RDS(on), critical for maintaining 1.8V core supply as Li+ discharges below 2.5V. |
| Current-Mode Control | Provides inherent cycle-by-cycle current limiting (1.6A peak) and fast transient response (<50μs recovery from 0→500mA load step). |
| Thermal & Short-Circuit Protection | Auto-recovering thermal shutdown at 145°C and frequency-foldback short-circuit protection prevent damage during fault conditions. |
| Low Quiescent Current | 600μA operating supply current and <0.1μA shutdown current extend battery life in always-on sensor or standby subsystems. |
Applications
| Smartphone Core Rail | DSP Processor Supply |
|---|---|
Use Scenario: Powering ARM Cortex-A series application processors requiring stable 1.2V/1.8V core voltage from single-cell Li-ion battery (2.7–4.2V). IC Role / Device Role / Timing Role: Primary synchronous buck regulator delivering regulated core voltage with fast load transient response and 100% duty cycle support during battery sag. Use Value: Maintains processor operation down to 2.5V input while sustaining 800mA peak current and minimizing thermal rise in thin-profile handset PCBs. | Use Scenario: Supplying 1.5V I/O and 1.0V core rails for audio DSPs in portable media players with tight ripple and noise budgets. IC Role / Device Role / Timing Role: High-efficiency, low-noise DC/DC converter with 1MHz fixed frequency to simplify EMI filtering and avoid AM band interference. Use Value: Achieves <10mVpp output ripple with 4.7μF X5R ceramic output cap, meeting DSP analog section noise requirements without additional LDO post-regulation. |
| Digital Camera Sensor Bias | Portable Instrument ADC Reference |
Use Scenario: Generating clean 2.8V bias for CMOS image sensors in compact digital still/video cameras powered by Li-ion cells. IC Role / Device Role / Timing Role: Compact, thermally efficient step-down converter placed near sensor module to minimize IR drop and noise coupling. Use Value: Delivers 2.8V @ 300mA with <15mVpp ripple using local 10μF ceramic cap, ensuring sensor SNR remains unaffected by power supply noise. | Use Scenario: Providing precision 3.3V reference supply for 16-bit SAR ADCs in handheld test equipment with battery-only operation. IC Role / Device Role / Timing Role: Low-drift, low-noise buck regulator feeding ADC reference input; FB accuracy (±12mV) ensures <0.4% full-scale error contribution. Use Value: Enables direct ADC reference use without external buffer or trimming, reducing BOM count and layout complexity in space-constrained instrument modules. |
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 |
|---|---|---|---|
| MP2151DJ-LF-Z | Successor device: 2A output, 2.5–6V input, 0.6V ref, 1.5MHz fSW, improved thermal resistance (θJA = 190°C/W), same TSOT23-5 package. | Higher current capability and faster switching allow smaller inductors; not pin-compatible due to different EN logic threshold and FB compensation. | Select when upgrading for >800mA loads or tighter size constraints; requires PCB redesign and loop compensation adjustment. |
| TPS62231DRYR | Texas Instruments part: 600mA, 2.05–6.5V input, 0.6V ref, 3.6MHz fSW, 12μA IQ, DSBGA-6 package (1.0×1.5mm). | Higher switching frequency enables 1μH inductors and lower output capacitance; lacks 100% duty cycle and has lower max current. | Prefer for ultra-low-IQ battery applications where 600mA suffices and board area is more constrained than thermal budget. |
Compared with MP2105DJ-LF-Z, MP2151DJ-LF-Z offers higher current and better thermal performance but requires layout and compensation changes, while TPS62231DRYR trades current capability for ultra-small size and lower quiescent current-making each suitable for distinct power architecture priorities.
Availability
MP2105DJ-LF-Z is available at Aetrix Electronics and suitable for smartphone power management, portable media player DC/DC conversion, and digital camera sensor biasing requiring stable component supply and long-term industrial availability.
Supply support for MP2105DJ-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 MP2105 belongs to MPS's legacy high-efficiency DC/DC converter product line, engineered specifically for space- and thermal-constrained portable electronics powered by single-cell Li-ion batteries.
FAQ
What is the maximum recommended output current for MP2105DJ-LF-Z at 3.3V input and 1.8V output?
The MP2105DJ-LF-Z delivers up to 800mA continuously under these conditions, assuming adequate PCB copper area for thermal dissipation (θJA = 220°C/W), ambient temperature ≤+60°C, and proper input/output capacitor selection per datasheet guidelines. Derating applies above +60°C ambient.
Does MP2105DJ-LF-Z support adjustable output voltage, and what is the minimum achievable value?
Yes, output voltage is set externally via a resistor divider on the FB pin. The internal reference is 0.600V ±12mV, allowing outputs as low as 0.6V. For example, a 1.2V output uses R1 = R2 = 499kΩ; lower voltages require proportionally smaller R2 values while maintaining divider current >10× FB bias current.
Can MP2105DJ-LF-Z operate with input voltage equal to the desired output voltage?
Yes-it supports true 100% duty cycle operation, enabling dropout regulation when VIN approaches VOUT. At VIN = 2.5V and VOUT = 1.8V, it sustains regulation by holding the PFET fully on, limited only by RDS(on) (0.42Ω) and inductor DCR.
What thermal protection mechanisms does MP2105DJ-LF-Z include?
The device integrates a thermal shutdown circuit that triggers at 145°C junction temperature, disabling switching until die temperature falls below the hysteresis threshold (~15°C below trip). Recovery is automatic and does not require cycling EN. This protects against sustained overload or inadequate heatsinking.
Is MP2105DJ-LF-Z pin-compatible with other Monolithic Power Systems buck converters?
No-MP2105DJ-LF-Z in TSOT23-5 is not pin-compatible with newer MPS converters like MP2151 or MP2161, which use different pinouts (e.g., separate PGND, different EN thresholds, or added COMP pins). Direct replacement requires schematic and layout revision.
What is the recommended input capacitor for MP2105DJ-LF-Z in a typical 3.3V-to-1.8V application?
A 4.7μF X5R or X7R ceramic capacitor placed within 2mm of the IN and GND pins is recommended. This value suppresses high-frequency switching noise and limits surge current; adding a 0.1μF ceramic in parallel improves high-frequency decoupling. Total ESR should remain <50mΩ.
How does the current-mode control architecture improve transient response in MP2105DJ-LF-Z?
Current-mode control enables cycle-by-cycle peak current limiting and inherent feedforward line regulation. Combined with slope compensation, it yields <50μs output voltage recovery from 0→500mA load steps and stable loop behavior across 0–100% duty cycles-critical for powering burst-mode processors and sensors.
MP2105DJ-LF-Z Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Monolithic Power Systems Inc.
- Series:
- -
- Package/Case:
- SOT-23-5 Thin, TSOT-23-5
- 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):
- 2.5V
- Voltage - Input (Max):
- 6V
- Voltage - Output (Min/Fixed):
- 0.6V
- Voltage - Output (Max):
- 6V
- Current - Output:
- 800mA
- Frequency - Switching:
- 1.05MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TSOT-23-5
MP2105DJ-LF-Z FAQ
1.How can I place an order for MP2105DJ-LF-Z through Aetrix?
Please submit a Request for Quotation (RFQ) for MP2105DJ-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 MP2105DJ-LF-Z reliable?
The price and inventory of MP2105DJ-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 MP2105DJ-LF-Z is usually 5 days.
3.What payment methods are accepted for MP2105DJ-LF-Z?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MP2105DJ-LF-Z transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MP2105DJ-LF-Z?
MP2105DJ-LF-Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MP2105DJ-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 MP2105DJ-LF-Z?
For technical support, including MP2105DJ-LF-Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MP2105DJ-LF-Z requirements.
6.How does Aetrix verify that MP2105DJ-LF-Z is sourced from the original manufacturer or authorized distributors?
All MP2105DJ-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 MP2105DJ-LF-Z meets industry standards.
7.What is the process for return or replacement of MP2105DJ-LF-Z?
All MP2105DJ-LF-Z units undergo pre-shipment inspection (PSI). If there is an issue with MP2105DJ-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 MP2105DJ-LF-Z part is unused and in its original packaging.
Return procedure for MP2105DJ-LF-Z:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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