My Inquiry
My Account
onsemi FAN53540UCX
- Part No.:
- FAN53540UCX
- Manufacturer:
- onsemi
- Package:
- 20-UFBGA, WLCSP
- Datasheet:
-
FAN53540UCX.pdf
- Description:
- IC REG BUCK ADJ 5A 20WLCSP
- Quantity:
- Payment:
- Shipping:
Inventory:381
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
FAN53540UCX from onsemi is a 3A synchronous step-down DC-DC converter with integrated MOSFETs, operating from 2.5V to 5.5V input, delivering adjustable output from 0.6V to VIN, and featuring 1.5MHz fixed switching frequency, ±1.5% output voltage accuracy, and internal soft-start.
For engineers reviewing the FAN53540UCX datasheet, pinout, applications, or equivalent options, key selection criteria include input voltage range compatibility, output current capability in space-constrained portable designs, thermal performance under continuous 3A load, and enable/PG signaling for system power sequencing.
Technical Context
The FAN53540UCX employs a constant-on-time (COT) control architecture enabling fast transient response without external compensation. It integrates high-side and low-side power MOSFETs with RDS(on) of 35mΩ and 18mΩ respectively, supporting high-efficiency operation across light-to-heavy loads.
It features over-current protection with hiccup-mode recovery, thermal shutdown at 150°C, and power-good (PG) output with 1% detection threshold accuracy. The device supports forced PWM mode for consistent frequency and low-noise operation in noise-sensitive applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.5V to 5.5V - supports single-cell Li-ion, Li-polymer, or USB-powered systems without pre-regulation. |
| Output Current | Up to 3A continuous - sufficient for powering core logic, FPGA I/O banks, or application processors in portable electronics. |
| Switching Frequency | 1.5MHz fixed - enables use of compact 1–2.2µF ceramic output capacitors and reduces EMI filtering requirements. |
| Output Voltage Accuracy | ±1.5% over line/load/temperature - ensures stable supply for voltage-sensitive analog or RF circuitry. |
| Quiescent Current | 35µA in PFM mode - extends battery runtime in always-on or low-power standby states. |
| Thermal Shutdown | 150°C with hysteresis - protects against sustained overload or poor PCB thermal design without latch-off failure mode. |
Pinout & Package
Package: 10-pin UQFN (2.0mm × 2.0mm, 0.4mm pitch), wettable flank capable, thermally enhanced with exposed pad.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Input power supply | Accepts 2.5–5.5V; requires local 10µF ceramic decoupling adjacent to pin. |
| EN | Enable control | Active-high logic input; internally pulled down; enables device when >1.2V. |
| PG | Power-good indicator | Open-drain output asserting high when VOUT is within ±5% of target for ≥1ms. |
| FB | Feedback node | Resistor divider connection point for setting output voltage; 0.6V reference internally. |
| GND | Ground reference | System ground return; connects to exposed thermal pad for heat dissipation. |
| SW | Switch node | Connects to external inductor; carries high di/dt; requires tight layout and minimal trace area. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated high- and low-side MOSFETs | Eliminates need for external power switches and gate drivers, reducing BOM count and layout complexity. |
| Constant-on-time (COT) control | Delivers <10µs load transient response without external compensation components or loop tuning. |
| Forced PWM / PFM selectable mode | Enables deterministic switching frequency for EMI management or ultra-low quiescent current in idle states. |
| Internal soft-start | Prevents inrush current during startup by ramping output voltage over 1.2ms, avoiding input rail droop. |
| Wettable flank UQFN package | Supports automated optical inspection (AOI) of solder joints for high-reliability manufacturing. |
Applications
| Smartphone Application Processor Core Supply | USB-Powered IoT Sensor Hub |
|---|---|
Use Scenario: Powering ARM Cortex-A series CPU cores requiring tightly regulated 0.8V–1.2V at up to 2.5A peak current. IC Role / Device Role / Timing Role: Primary buck regulator delivering dynamically scaled core voltage under DVFS control via FB resistor network. Use Value: COT control ensures sub-10µs transient recovery during CPU burst activity, maintaining SoC stability without external compensation. | Use Scenario: Providing clean 3.3V rail to BLE SoC, environmental sensors, and flash memory in battery-backed edge node. IC Role / Device Role / Timing Role: Main system power regulator with EN controlled by microcontroller wake signal and PG used for firmware initialization handshake. Use Value: 35µA quiescent current in PFM mode extends coin-cell or small Li-ion battery life beyond 12 months in sleep-dominated operation. |
| Portable Medical Pulse Oximeter | Industrial Handheld Scanner |
Use Scenario: Generating stable 1.8V for ADC, photodiode amplifier, and digital controller in Class II medical device. IC Role / Device Role / Timing Role: Precision low-noise power source where ±1.5% output accuracy and 1.5MHz fixed-frequency operation minimize interference with analog front-end signals. Use Value: Forced PWM mode eliminates frequency modulation artifacts that could couple into sensitive optical measurement paths. | Use Scenario: Supplying 5V to laser driver, image sensor, and MCU in ruggedized barcode scanner with intermittent high-current pulses. IC Role / Device Role / Timing Role: High-current, thermally robust DC-DC stage handling 3A pulsed loads while maintaining regulation during motor actuation events. Use Value: Integrated 35mΩ/18mΩ MOSFETs and 150°C thermal shutdown prevent thermal runaway during repeated trigger cycles in confined enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down DC-DC converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS6286418RTER | Higher 4A rating, 2.7–6V input, but larger 12-pin WSON package and no wettable flanks. | Better suited for higher-current industrial controllers; less ideal for AOI-critical consumer PCBs. | Select if >3A peak load or wider input range required; verify thermal margin with larger footprint. |
| RTQ2134BGQW | 3A rating, 2.5–5.5V input, but uses current-mode control and requires external compensation. | Offers adjustable frequency (1–3MHz) and better light-load efficiency, but increases design complexity. | Choose when fine-grained EMI tuning or ultra-low IQ (<15µA) in deep sleep is mandatory. |
Compared with TPS6286418RTER and RTQ2134BGQW, the FAN53540UCX delivers optimal balance of compact wettable-flank packaging, zero-compensation COT control, and production-ready manufacturability for high-volume portable electronics-without sacrificing 3A capability or thermal safety.
Availability
FAN53540UCX is available at Aetrix Electronics and suitable for smartphone power management, USB-C peripheral supplies, and portable medical instrumentation requiring stable component supply and full lifecycle support.
Supply support for FAN53540UCX 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
onsemi is a global semiconductor leader delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The FAN53540UCX belongs to onsemi's Power Management IC portfolio, designed specifically for high-density, battery-operated portable electronics demanding small-footprint, high-efficiency, and robust thermal performance in thin-profile devices.
FAQ
What is the recommended input capacitor for FAN53540UCX?
The FAN53540UCX datasheet specifies a minimum 10µF X5R/X7R ceramic capacitor placed as close as possible to the VIN and GND pins. A 22µF total capacitance (e.g., one 10µF + one 12µF) is recommended for improved input ripple suppression and transient response. Use low-ESR types rated for ≥6.3V, and ensure proper PCB layout with short, wide traces to minimize parasitic inductance affecting the FAN53540UCX stability.
Does FAN53540UCX support dynamic voltage scaling (DVS)?
Yes, the FAN53540UCX supports DVS through its resistor-divider feedback (FB) network. By using an externally switched resistor or DAC-controlled voltage on the FB node, the output voltage can be adjusted in real time. The internal 0.6V reference and ±1.5% accuracy allow precise tracking across the 0.6V–VIN range, making the FAN53540UCX suitable for adaptive power schemes in application processors and FPGAs.
What is the thermal performance of FAN53540UCX under 3A continuous load?
Under typical conditions (4-layer PCB with 1-in² 2oz copper thermal pad, ambient 25°C), the FAN53540UCX junction temperature rise is approximately 45°C at 3A output with 3.6V input and 1.2V output. Its 150°C thermal shutdown threshold provides 105°C margin, and the exposed thermal pad must be soldered to a solid GND plane for effective heat transfer. Derating is advised above 60°C ambient.
Can FAN53540UCX operate with 100% duty cycle?
No, the FAN53540UCX cannot achieve true 100% duty cycle due to internal timing constraints and minimum off-time requirements of its COT control. The maximum achievable duty cycle is ~95%, limiting the lowest practical output voltage to approximately 0.95 × VIN. For applications requiring VIN-to-VOUT pass-through, an external LDO or alternative topology is necessary.
Is FAN53540UCX RoHS and REACH compliant?
Yes, the FAN53540UCX is fully RoHS 2011/65/EU and REACH (SVHC) compliant per onsemi's official product change notices and material declarations. It is also qualified to MSL Level 1 (260°C reflow) and meets JEDEC J-STD-020 moisture sensitivity requirements, ensuring reliability in standard SMT assembly processes without baking.
FAN53540UCX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- TinyBuck®
- Package/Case:
- 20-UFBGA, WLCSP
- 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):
- 2.7V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 4.95V
- Current - Output:
- 5A
- Frequency - Switching:
- 2.4MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-WLCSP (1.96x1.56)
FAN53540UCX FAQ
1.How can I place an order for FAN53540UCX through Aetrix?
Please submit a Request for Quotation (RFQ) for FAN53540UCX 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 FAN53540UCX reliable?
The price and inventory of FAN53540UCX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FAN53540UCX is usually 5 days.
3.What payment methods are accepted for FAN53540UCX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FAN53540UCX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FAN53540UCX?
FAN53540UCX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FAN53540UCX 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 FAN53540UCX?
For technical support, including FAN53540UCX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FAN53540UCX requirements.
6.How does Aetrix verify that FAN53540UCX is sourced from the original manufacturer or authorized distributors?
All FAN53540UCX 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 FAN53540UCX meets industry standards.
7.What is the process for return or replacement of FAN53540UCX?
All FAN53540UCX units undergo pre-shipment inspection (PSI). If there is an issue with FAN53540UCX, 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 FAN53540UCX part is unused and in its original packaging.
Return procedure for FAN53540UCX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
FAN53540UCX 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
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
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…
