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onsemi FAN53555UC18X
- Part No.:
- FAN53555UC18X
- Manufacturer:
- onsemi
- Package:
- 20-UFBGA, WLCSP
- Datasheet:
-
FAN53555UC18X.pdf
- Description:
- IC REG BUCK PROG 5A 20WLCSP
- Quantity:
- Payment:
- Shipping:
Inventory:1,583
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Product details
Overview
FAN53555UC18X from onsemi is a digitally programmable 5 A synchronous step-down DC-DC regulator with I²C interface, fixed 2.4 MHz switching frequency, and 2.5–5.5 V input range. It delivers 1.02 V / 1.15 V dual-default output voltage in 10 mV steps (0.6–1.23 V range), optimized for core power in mobile application processors including ARM-based SoCs in smartphones and tablets.
For engineers reviewing the FAN53555UC18X datasheet, pinout, applications, or equivalent options, key selection criteria include its 5 A continuous output capability, 60 µA typical quiescent current in PFM mode, WLCSP-20 package footprint, and support for dynamic voltage scaling via I²C up to 3.4 Mbps.
Technical Context
The FAN53555UC18X employs a proprietary non-linear fixed-frequency PWM modulator with synchronous rectification, enabling fast load transient response independent of output capacitor ESR. Its architecture supports seamless auto-transition between PFM (for light-load efficiency) and forced PWM (for constant-frequency operation).
It integrates hardware enable (EN), voltage-select logic (VSEL), and I²C-controlled registers for output voltage (VSEL0/VSEL1), slew rate (8-step programmable), and mode control. Input under-voltage lockout (2.45 V threshold) and over-voltage protection (6.15 V shutdown) ensure robust system-level power integrity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 5 A continuous - supports high-performance CPU/GPU core rails without external current sharing. |
| Switching Frequency | 2.4 MHz nominal - enables ultra-small 330 nH inductors and low-ESR ceramic capacitors (e.g., 44 µF total COUT). |
| I²C Interface Speed | Up to 3.4 Mbps - allows real-time dynamic voltage scaling (DVS) during processor DVFS transitions. |
| Quiescent Current | 60 µA typical in PFM mode - minimizes battery drain during idle/sleep states in portable devices. |
| Output Voltage Range | 0.6–1.23 V in 10 mV steps - matches standard core voltage requirements for Arm Krait/OMAP/NovaThor processors. |
| Input Voltage Range | 2.5–5.5 V - compatible with single-cell Li-ion (3.0–4.2 V), USB PD (5 V), and boosted battery rails. |
| Package | 20-bump WLCSP, 1.6 × 2.0 mm - ultra-compact footprint for space-constrained mobile PCBs. |
Pinout & Package
Package: 20-bump Wafer-Level Chip Scale Package (WLCSP), 1.6 mm × 2.0 mm, 0.4 mm pitch, bottom-side solder bumps.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A1 | VSEL | Selects between VSEL0 (1.02 V default) and VSEL1 (1.15 V default) output voltage registers via logic level. |
| A2 | EN | Hardware enable: LOW disables regulator and reduces supply current to <1 µA; register state preserved. |
| A3 | SCL | I²C clock input - supports Standard/Fast/Fast Plus/High-Speed modes up to 3.4 Mbps. |
| A4 | VOUT | Regulated output sense node - must connect directly to COUT for accurate feedback. |
| B1 | SDA | I²C bidirectional data line - open-drain, requires external pull-up. |
| B2–B3, C1–C4 | GND | Power ground return for low-side MOSFET and input/output capacitors - critical for EMI and thermal performance. |
| B4 | AGND | Analog ground reference for internal circuitry - isolated from noisy digital/power GND paths. |
| D1–D2, E1–E2 | VIN | Main input power rail - connects to 2.5–5.5 V source and local 10–20 µF CIN decoupling. |
| D3–D4, E3–E4 | SW | Switching node - drives external 330 nH inductor; requires tight layout to minimize ringing and EMI. |
Key Features
| Feature | Design Value |
|---|---|
| Digitally programmable output | Configurable via I²C in 10 mV steps across 0.6–1.23 V - enables precise core voltage tuning for process/voltage/temp corners. |
| PFM/PWM auto-mode transition | Maintains >80% efficiency from 10 mA to 5 A load - eliminates efficiency valley at light loads common in fixed-frequency converters. |
| Programmable slew rate | 8-step voltage transition control (0.5–64 mV/µs) - prevents overshoot/undershoot during DVS and ensures safe SoC voltage ramping. |
| Internal soft-start | ~135–175 µs startup to regulated VOUT - avoids inrush current and enables reliable start into pre-biased outputs. |
| Thermal & overload protection | 150°C thermal shutdown with 17°C hysteresis + cycle-by-cycle current limiting - protects IC and system during fault conditions. |
Applications
| Mobile Application Processor Core Power | Smartphone Baseband & Modem Power |
|---|---|
Use Scenario: Powers Arm-based application processors (e.g., Qualcomm Krait, TI OMAP) requiring dynamic voltage scaling during performance state transitions. IC Role / Device Role / Timing Role: Primary core voltage regulator with I²C-controlled output voltage and slew rate, synchronized to SoC DVFS commands. Use Value: Enables >80% efficiency across 10 mA–5 A load range and sub-100 ns transient response - critical for battery life and thermal management in thin form factors. | Use Scenario: Supplies baseband processors and LTE/5G modems where rapid load changes occur during RF transmission bursts. IC Role / Device Role / Timing Role: High-current, low-noise buck converter delivering stable 0.9–1.15 V core voltage with minimal output ripple (<40 mVpp). Use Value: 2.4 MHz switching frequency allows compact 0603/0805 passives; PFM mode maintains 60 µA IQ during modem sleep states. |
| Tablet & Ultra-Mobile PC SoC Power | Gaming Handheld GPU Core Supply |
Use Scenario: Delivers regulated core voltage to multi-core SoCs in tablets and UMPCs with aggressive power budget constraints. IC Role / Device Role / Timing Role: Main SoC core regulator supporting dual-default voltages (1.02 V / 1.15 V) selected by VSEL pin for performance vs. efficiency modes. Use Value: WLCSP-20 package (1.6 × 2.0 mm) saves PCB area versus QFN alternatives; 5 A rating eliminates need for parallel regulators. | Use Scenario: Powers discrete or integrated GPU cores in handheld gaming devices requiring burst current up to 5 A during rendering. IC Role / Device Role / Timing Role: High-efficiency synchronous buck supplying 0.8–1.2 V GPU core rail with fast transient recovery (<10 µs settling). Use Value: Best-in-class load transient response and 80%+ efficiency at 3 A ensures stable frame rates and reduced thermal throttling. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS628641RQYR | 4 A max output, 2.5–5.5 V input, 1.8–4.0 V output range; no I²C, uses VID pins for voltage selection. | Lacks digital programmability and dynamic slew control - suited for fixed-voltage or VID-based systems only. | Choose when I²C control is unnecessary and board space permits larger 1.96 × 2.16 mm QFN package. |
| RTQ2132BGQW | 5 A, 2.7–5.5 V input, 0.6–1.8 V output; I²C interface (1 MHz max); 2.2 MHz switching frequency. | Lower I²C speed (1 MHz vs. 3.4 Mbps) and wider output range - less precise for sub-1.2 V core rails. | Prefer when higher VIN min (2.7 V) is acceptable and full 3.4 Mbps DVS bandwidth is not required. |
Compared with TPS628641RQYR and RTQ2132BGQW, the FAN53555UC18X uniquely combines 5 A capability, 2.4 MHz operation, 10 mV I²C-programmable resolution, and 60 µA PFM quiescent current in a 1.6 × 2.0 mm WLCSP - making it optimal for space- and efficiency-critical mobile SoC core supplies.
Availability
FAN53555UC18X is available at Aetrix Electronics and suitable for smartphone, tablet, and ultra-mobile PC designs requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.
Supply support for FAN53555UC18X 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 (Nasdaq: ON) is a global semiconductor leader delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The FAN53555UC18X belongs to onsemi's TinyBuck® family of high-density, digitally programmable DC-DC regulators - engineered specifically for core power delivery in battery-powered mobile processors with stringent size, efficiency, and dynamic response requirements.
FAQ
What is the default output voltage configuration of the FAN53555UC18X?
The FAN53555UC18X has dual hardware-default output voltages: 1.02 V (VSEL0 register) and 1.15 V (VSEL1 register), selectable via the VSEL pin logic level. These values are factory-programmed and retained across shutdown cycles except during power-on reset. The full 0.6–1.23 V range is accessible via I²C writes to the VSEL registers in 10 mV increments.
Does the FAN53555UC18X support dynamic voltage scaling (DVS) during operation?
Yes, the FAN53555UC18X supports real-time DVS through its I²C interface, allowing software-controlled reprogramming of output voltage, slew rate, and operating mode (PFM/PWM) without interrupting regulation. The interface operates up to 3.4 Mbps, enabling sub-microsecond command execution - essential for synchronizing with Arm processor DVFS transitions.
What is the recommended inductor value and type for the FAN53555UC18X?
The FAN53555UC18X is characterized with a 330 nH shielded power inductor (e.g., Vishay IHLP1616ABERR47M01 or Toko DFE201612R-H-R33N), rated for ≥5 A DC current and ≤20 mΩ DCR. Inductance values up to 1.2 µH may be used with increased output capacitance, but 330 nH provides optimal balance of transient response, efficiency, and physical size for mobile applications.
How does the FAN53555UC18X manage efficiency across load conditions?
The FAN53555UC18X uses automatic PFM/PWM mode switching: below ~100 mA it enters single-pulse PFM with 60 µA typical quiescent current; above that threshold it transitions seamlessly to fixed 2.4 MHz PWM operation. This architecture sustains >80% efficiency from 10 mA to 5 A - eliminating the "efficiency valley" seen in conventional buck converters at light loads.
Is the FAN53555UC18X pin-compatible with other variants in the FAN53555 family?
Yes, all FAN53555 variants - including FAN53555UC00X, FAN53555UC05X, and FAN53555UC18X - share identical 20-bump WLCSP-20 packaging, pinout, and mechanical footprint. Functional differences (e.g., default voltages, pulse current rating, I²C address) are implemented internally and do not affect PCB layout or interconnect design.
FAN53555UC18X Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- TinyBuck®
- Package/Case:
- 20-UFBGA, WLCSP
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Programmable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2.5V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 0.6V
- Voltage - Output (Max):
- 1.23V
- 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)
FAN53555UC18X FAQ
1.How can I place an order for FAN53555UC18X through Aetrix?
Please submit a Request for Quotation (RFQ) for FAN53555UC18X 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 FAN53555UC18X reliable?
The price and inventory of FAN53555UC18X are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FAN53555UC18X is usually 5 days.
3.What payment methods are accepted for FAN53555UC18X?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FAN53555UC18X transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FAN53555UC18X?
FAN53555UC18X orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FAN53555UC18X 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 FAN53555UC18X?
For technical support, including FAN53555UC18X datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FAN53555UC18X requirements.
6.How does Aetrix verify that FAN53555UC18X is sourced from the original manufacturer or authorized distributors?
All FAN53555UC18X 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 FAN53555UC18X meets industry standards.
7.What is the process for return or replacement of FAN53555UC18X?
All FAN53555UC18X units undergo pre-shipment inspection (PSI). If there is an issue with FAN53555UC18X, 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 FAN53555UC18X part is unused and in its original packaging.
Return procedure for FAN53555UC18X:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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