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onsemi FAN2103EMPX
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- Part No.:
- FAN2103EMPX
- Manufacturer:
- onsemi
- Package:
- 25-WQFN Exposed Pad
- Datasheet:
-
FAN2103EMPX.pdf
- Description:
- IC REG BUCK ADJ 3A 25MLP
- Quantity:
- Payment:
- Shipping:
Inventory:2,098
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Product details
Overview
FAN2103EMPX from ON Semiconductor is a fully integrated synchronous buck regulator delivering 3 A output current with input voltage range of 3 V to 24 V, programmable switching frequency from 200 kHz to 600 kHz, and output voltage adjustable from 0.8 V to 90% VIN. It integrates high- and low-side MOSFETs in a thermally enhanced 5×6 mm MLP package and is used for point-of-load regulation in graphics cards and battery-powered equipment.
For engineers reviewing the FAN2103EMPX datasheet, pinout, applications, or equivalent options, key selection considerations include its -40°C to +85°C operating temperature range, external compensation capability, power-good signal, over-current limit programming via ILIM pin, and thermal/over-voltage/under-voltage protection features.
Technical Context
The FAN2103EMPX employs summing current-mode modulation with voltage feedforward, enabling stable loop control across wide input ranges. Its lossless current sensing supports accurate over-current detection and current-mode feedback without external sense resistors.
It integrates a 5×6 mm 25-pin MLP package with three exposed thermal pads (P1–P3) tied to SW, VIN, and PGND respectively, and uses internal synchronous bootstrap diode for high-side gate drive. The IC includes dedicated pins for ramp amplitude setting (RAMP), oscillator frequency programming (R(T)), and current-limit threshold adjustment (ILIM).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 3 A continuous - supports high-current PoL conversion without external MOSFETs. |
| Input Voltage Range | 3 V to 24 V - compatible with 5 V, 12 V, and 24 V industrial and computing rails. |
| Switching Frequency | 200 kHz to 600 kHz - programmable via RT resistor; enables EMI optimization and inductor size trade-offs. |
| Reference Voltage | 0.800 V ±5 mV at 25°C - sets output accuracy; tempco ≤70 ppm/°C over -40°C to +85°C. |
| Protection Features | Thermal shutdown at 160°C, over-voltage (115% VOUT), under-voltage (68% VOUT), and latched over-current - ensures robust fault handling. |
| Efficiency | Over 95% - achieved via fully synchronous operation and integrated low-RDS(ON) MOSFETs. |
| Soft-Start Time | 6.7 ms to full regulation - prevents inrush current; timing scales with oscillator frequency. |
Pinout & Package
The FAN2103EMPX is housed in a 5×6 mm, 25-pin Molded Leadless Package (MLP) with three exposed thermal pads (P1, P2, P3) for enhanced thermal dissipation. Pin 1 is BOOT; pins 6–12 are SW; pins 2–5 are VIN; pins 21–23 are PGND; pin 16 is VCC; pin 14 is EN; pin 13 is PGOOD; pin 19 is FB; pin 20 is COMP; pin 17 is ILIM; pin 18 is R(T); pin 25 is RAMP; pin 1 is BOOT; pin 24 is NC.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SW (Pins 6–12) | Switching Node | Connects to inductor and high-side MOSFET drain; carries high di/dt; requires low-inductance layout. |
| VIN (Pins 2–5) | Main Input Supply | Power input for both power stage and internal bias; multiple pins reduce IR drop and improve thermal spreading. |
| PGND (Pins 21–23) | Power Ground Return | Low-impedance return path for high-side and low-side MOSFET sources; must be tied to power plane under IC. |
| BOOT (Pin 1) | High-Side Gate Drive Supply | Connected via boot capacitor to SW; internal bootstrap diode recharges it during low-side conduction. |
| PGOOD (Pin 13) | Open-Drain Power-Good Flag | Pulls low when FB deviates >±10% from reference; asserts high only after soft-start completes and no faults exist. |
| EN (Pin 14) | Enable Control Input | Logic-high enable with internal pull-up; toggling resets latched faults; discharge current enables auto-restart timing. |
| FB (Pin 19) | Feedback Input | Monitors output via resistor divider; 650 nA sink current enables open-circuit detection and precise VREF referencing. |
| COMP (Pin 20) | Error Amplifier Output | External Type-2 or Type-3 compensation network connects here to FB for loop stability tuning. |
| ILIM (Pin 17) | Current Limit Programming | 10 µA current source to AGND sets trip threshold; allows reduction below default 5 A nominal limit. |
| R(T) (Pin 18) | Oscillator Frequency Set | Resistor to AGND programs fSW from 200–600 kHz; equation: f = (135 + 65·RT)/10⁶ kHz. |
| RAMP (Pin 25) | Voltage Feedforward Input | Resistor to VIN sets ramp amplitude; improves line transient response and modulator gain stability. |
| AGND (Pin 16) | Analog Ground Reference | Signal ground for error amp, reference, and comparators; must be isolated from noisy PGND except at single-point tie. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated Synchronous MOSFETs | Eliminates need for external high- and low-side switches; reduces BOM count and layout area. |
| External Compensation | Enables loop bandwidth and phase margin optimization for diverse output capacitors (ceramic, polymer, low-ESR). |
| Programmable Over-Current Limit | Adjustable trip point via ILIM pin resistor allows design margin tuning without changing IC or layout. |
| Power-Good Signal with Fault Latch | PGOOD remains low during soft-start and latched faults; enables system-level sequencing and safe startup. |
| Thermally Enhanced MLP Package | 5×6 mm footprint with three thermal pads achieves θJ-PCB = 35°C/W on 4-layer board; supports 3 A continuous load at +85°C ambient. |
Applications
| Graphics Cards | Battery-Powered Equipment |
|---|---|
Use Scenario: Providing core GPU voltage (e.g., 1.05 V, 1.2 V) from 12 V rail in compact PCIe add-in cards. IC Role / Device Role / Timing Role: Primary point-of-load buck regulator with fast transient response and tight output regulation. Use Value: Delivers 3 A at >95% efficiency with minimal external components; thermal pad layout supports sustained GPU boost clocks. | Use Scenario: Regulating processor or FPGA core voltage in portable test instruments or handheld medical devices. IC Role / Device Role / Timing Role: High-efficiency DC-DC converter supporting wide-input battery operation (3–24 V) with pre-bias startup capability. Use Value: Operates down to 3 V input and starts against pre-biased outputs; -40°C rating ensures reliability in outdoor or industrial field use. |
| Set-Top Boxes | Servers |
Use Scenario: Generating 3.3 V or 5 V auxiliary rails for SoC, memory, and interface ICs in consumer entertainment systems. IC Role / Device Role / Timing Role: Secondary buck regulator with programmable frequency to avoid AM band interference and meet EMI standards. Use Value: 200–600 kHz frequency range allows EMI filter optimization; PGOOD enables clean power sequencing with microcontroller. | Use Scenario: Supplying DDR memory termination voltage (VTT) or auxiliary logic rails in rack-mounted servers. IC Role / Device Role / Timing Role: Compact, high-current PoL regulator with thermal shutdown and over-voltage protection for mission-critical infrastructure. Use Value: Latched fault behavior prevents uncontrolled restart during overloads; 160°C thermal cutoff protects downstream ASICs and memory modules. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MP2315DJ-LF-Z | 2.5 A max output, 4.5–24 V input, fixed 500 kHz fSW, no RAMP or ILIM programming pins. | Lacks feedforward and adjustable current limit; suited for simpler, cost-sensitive designs without dynamic line/load requirements. | Choose MP2315DJ-LF-Z if external compensation and fine-grained protection tuning are not required. |
| TPS54332DR | 3 A, 3.5–28 V input, adjustable frequency (200–2500 kHz), but requires external high-side MOSFET and bootstrap capacitor. | Higher BOM count and layout complexity; better for designs needing >24 V input or ultra-low quiescent current. | Choose TPS54332DR if input exceeds 24 V or if discrete MOSFET selection is preferred for thermal or reliability reasons. |
Compared with MP2315DJ-LF-Z and TPS54332DR, the FAN2103EMPX uniquely combines 3 A integrated power stage, -40°C to +85°C rating, RAMP feedforward, and ILIM programmability in a 5×6 mm MLP-making it optimal for space-constrained, thermally demanding PoL applications where design flexibility and protection granularity matter.
Availability
FAN2103EMPX is available at Aetrix Electronics and suitable for graphics cards, battery-powered equipment, and set-top boxes requiring stable component supply, extended temperature operation, and high-efficiency point-of-load conversion.
Supply support for FAN2103EMPX 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
ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power and signal management solutions, with leadership in automotive, industrial, cloud, and edge computing markets.
The FAN2103EMPX belongs to the TinyBuck™ family of integrated synchronous buck regulators, designed specifically for compact, high-current point-of-load applications where minimal external components, thermal performance, and flexible protection are critical.
FAQ
What is the operating temperature range of the FAN2103EMPX?
The FAN2103EMPX is rated for operation from -40°C to +85°C ambient temperature. This extended range distinguishes it from the standard FAN2103MPX (-10°C to +85°C) and makes it suitable for industrial and outdoor battery-powered equipment where cold-start reliability is essential. The device incorporates thermal shutdown at 160°C junction temperature with 30°C hysteresis, ensuring safe operation across its full ambient range.
How does the FAN2103EMPX achieve over-95% efficiency?
The FAN2103EMPX achieves over 95% efficiency through fully synchronous operation using integrated low-RDS(ON) MOSFETs, elimination of external Schottky losses, and optimized gate drive architecture. Its advanced BiCMOS process minimizes conduction and switching losses, while the 5×6 mm MLP package with three thermal pads enables efficient heat transfer to the PCB. Efficiency is validated at 1.8 VOUT, 3 A load, and 12 V input per the datasheet's Figure 11.
Can the FAN2103EMPX start up with a pre-biased output?
Yes, the FAN2103EMPX supports pre-biased startup. Its soft-start circuit inhibits full synchronous rectification until the internal ramp reaches ~0.76 V, preventing inductor current "ratcheting" when VOUT is already present. This behavior is confirmed in Figure 16 of the datasheet and applies directly to the FAN2103EMPX, which shares identical functional specifications with the FAN2103MPX except for temperature grade.
What is the purpose of the RAMP pin on the FAN2103EMPX?
The RAMP pin on the FAN2103EMPX provides voltage feedforward by setting internal ramp amplitude proportional to VIN. A resistor from RAMP to VIN adjusts modulator gain to compensate for input voltage variations, improving line transient response and loop stability. For example, at 12 V input, RRAMP ≈ 200 kΩ yields ~0.53 V pk-pk ramp amplitude-critical for maintaining consistent current-mode control across the 3–24 V input range of the FAN2103EMPX.
Does the FAN2103EMPX require external compensation, and why?
Yes, the FAN2103EMPX requires external compensation via the COMP and FB pins because it uses a summing current-mode architecture that benefits from tailored loop dynamics. External Type-2 or Type-3 networks allow designers to optimize phase margin and bandwidth for specific output capacitors (e.g., ceramic, polymer) and load conditions. This flexibility ensures stability across varying layouts and applications-unlike fixed-compensation regulators-and is explicitly supported in the FAN2103EMPX datasheet's Figure 23 and Section 11.
FAN2103EMPX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- TinyBuck®
- Package/Case:
- 25-WQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3V
- Voltage - Input (Max):
- 24V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 21.6V
- Current - Output:
- 3A
- Frequency - Switching:
- 300kHz ~ 600kHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 25-MLP (6x5)
FAN2103EMPX FAQ
1.How can I place an order for FAN2103EMPX through Aetrix?
Please submit a Request for Quotation (RFQ) for FAN2103EMPX 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 FAN2103EMPX reliable?
The price and inventory of FAN2103EMPX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FAN2103EMPX is usually 5 days.
3.What payment methods are accepted for FAN2103EMPX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FAN2103EMPX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FAN2103EMPX?
FAN2103EMPX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FAN2103EMPX 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 FAN2103EMPX?
For technical support, including FAN2103EMPX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FAN2103EMPX requirements.
6.How does Aetrix verify that FAN2103EMPX is sourced from the original manufacturer or authorized distributors?
All FAN2103EMPX 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 FAN2103EMPX meets industry standards.
7.What is the process for return or replacement of FAN2103EMPX?
All FAN2103EMPX units undergo pre-shipment inspection (PSI). If there is an issue with FAN2103EMPX, 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 FAN2103EMPX part is unused and in its original packaging.
Return procedure for FAN2103EMPX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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