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onsemi FAN53555UC042X
- Part No.:
- FAN53555UC042X
- Manufacturer:
- onsemi
- Package:
- 20-UFBGA, WLCSP
- Datasheet:
-
FAN53555UC042X.pdf
- Description:
- IC REG BUCK PROG 5A 20WLCSP
- Quantity:
- Payment:
- Shipping:
Inventory:3,000
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Product details
Overview
FAN53555UC042X from onsemi is a digitally programmable 5 A synchronous buck regulator with I²C interface, 2.4 MHz fixed switching frequency, and 0.603–1.411 V output voltage range in 12.826 mV steps. It delivers >80% efficiency from 10 mA to 5 A load, supports 2.5–5.5 V input, and targets core power delivery for mobile application processors.
For engineers reviewing the FAN53555UC042X datasheet, pinout, applications, or equivalent options, key selection considerations include its WLCSP-20 package, register-reset-on-EN-low behavior, I²C slave address C4, PFM/PWM auto-mode transition, and 330 nH inductor compatibility for compact Li-ion-powered handheld designs.
Technical Context
The FAN53555UC042X uses a proprietary non-linear fixed-frequency PWM modulator with synchronous rectification, enabling fast load transient response independent of output capacitor ESR. Its 2.4 MHz nominal switching frequency allows ceramic output capacitors and small external inductors (330 nH typical).
It operates in auto PFM/PWM mode: at light loads (<~100 mA), it enters single-pulse PFM with 60 µA typical quiescent current; above threshold, it switches seamlessly to fixed-frequency 2.4 MHz PWM. The EN pin resets all registers to defaults when pulled low - a distinguishing feature of the 04/042/24/79 options.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 5 A continuous; enables single-core processor rail without parallel devices |
| Switching Frequency | 2.4 MHz nominal; permits 330 nH inductor and compact 0603/0805 MLCCs |
| Input Voltage Range | 2.5 V to 5.5 V; compatible with single-cell Li-ion (3.0–4.2 V) and USB PD (5 V) |
| Programmable Output | 0.603–1.411 V in 12.826 mV steps via I²C; supports dynamic voltage scaling for ARM/Krait cores |
| I²C Interface | Up to 3.4 Mbps Fast Mode Plus; enables real-time VOUT reprogramming during operation |
| Quiescent Current | 60 µA typical in PFM mode; extends battery runtime in standby/sleep states |
| 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/VSEL1 register banks; HIGH = VSEL1, LOW = VSEL0 |
| A2 | EN | Hardware enable; LOW forces shutdown and resets all registers to defaults (042-specific behavior) |
| A3 | SCL | I²C clock input; supports up to 3.4 MHz Fast Mode Plus timing |
| A4 | VOUT | Regulated output sense node; must connect directly to COUT with minimal trace length |
| 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 |
| B4 | AGND | Analog ground reference; isolated from high-dV/dt digital paths to minimize noise coupling |
| D1–D2, E1–E2 | VIN | Main input power rail; connects to 2.5–5.5 V source and CIN with shortest possible path |
| D3–D4, E3–E4 | SW | Switching node; connects to inductor; high di/dt path requiring tight layout and copper fill |
Key Features
| Feature | Design Value |
|---|---|
| Digitally programmable slew rate | Eight selectable rates (0.5–64 mV/µs); prevents overshoot during DVS transitions |
| Auto PFM/PWM mode transition | Seamless switch at ~100 mA load; maintains >80% efficiency from 10 mA to 5 A |
| Internal soft-start | Ramps internal reference to limit inrush; supports startup into pre-biased outputs |
| Input UVLO with hysteresis | 2.45 V turn-on / 2.1 V turn-off; prevents erratic operation during battery sag |
| Thermal shutdown + hysteresis | 150 °C trip / 133 °C recovery; protects die under sustained overload or poor airflow |
Applications
| Smartphone Application Processor Core Rail | Tablet GPU Power Delivery |
|---|---|
Use Scenario: Powers ARM Cortex-A series CPU cores in flagship smartphones with dynamic voltage/frequency scaling (DVFS). IC Role / Device Role / Timing Role: Primary core buck regulator; responds to SoC VDD requests via I²C within microseconds. Use Value: 12.826 mV output steps and programmable slew rate enable precise, glitch-free voltage transitions during DVFS, reducing system-level power waste. | Use Scenario: Supplies graphics processing unit (GPU) in Android tablets requiring rapid load changes during gaming or UI rendering. IC Role / Device Role / Timing Role: High-current synchronous buck converter delivering stable 0.8–1.2 V at up to 5 A peak. Use Value: 2.4 MHz switching and best-in-class load transient response minimize output voltage deviation (<±40 mV) during 0.1–1.5 A load steps, preserving GPU stability. |
| Ultra-Mobile PC SoC Power | Connected Gaming Handheld Core Supply |
Use Scenario: Provides configurable core voltage to Intel Atom or Qualcomm Snapdragon SoCs in fanless UMPCs. IC Role / Device Role / Timing Role: Digitally programmable buck regulator with register-reset-on-EN behavior for deterministic boot sequencing. Use Value: EN pin reset-to-default ensures known VOUT state after cold boot or brown-out, eliminating firmware dependency for initial rail configuration. | Use Scenario: Delivers core power to custom ASICs in portable gaming devices (e.g., Steam Deck–class hardware) with aggressive thermal constraints. IC Role / Device Role / Timing Role: Compact WLCSP-20 buck regulator operating from single-cell Li-ion (3.0–4.2 V) with integrated OVP/OTP protection. Use Value: Input over-voltage protection (6.2 V trip) and 150 °C thermal shutdown prevent damage during accidental 5 V adapter misconnection or sustained GPU load. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS628640RQYR | 4 A max output, 1.8–5.5 V input, 0.4–1.2 V programmable output via I²C; 4 MHz switching; 1.18 mm × 0.73 mm DSBGA | Lower current rating and narrower output range; optimized for sub-1 V core rails only | Choose for space-constrained sub-1 V applications where 4 A suffices and higher switching frequency reduces inductor size |
| RTQ2132BGQW | 5 A, 2.5–5.5 V input, 0.6–1.8 V output via I²C; 2.2 MHz switching; 1.96 mm × 1.56 mm WLCSP | Wider output range (up to 1.8 V), no register-reset-on-EN behavior, different I²C address mapping | Choose when higher maximum output voltage or absence of automatic register reset is required for system control logic |
Compared with TPS628640RQYR and RTQ2132BGQW, the FAN53555UC042X uniquely combines 5 A capability, 0.603–1.411 V programmability in 12.826 mV steps, register-reset-on-EN functionality, and 2.4 MHz operation in a 1.6 × 2.0 mm WLCSP - making it optimal for mobile SoC core rails demanding deterministic boot and fine-grained DVFS.
Availability
FAN53555UC042X is available at Aetrix Electronics and suitable for smartphone application processor core rails, tablet GPU power delivery, and ultra-mobile PC SoC supply requiring stable component supply, consistent WLCSP-20 sourcing, and long-term lifecycle support.
Supply support for FAN53555UC042X 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 supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The FAN53555UC042X belongs to onsemi's TinyBuck® family of high-efficiency, digitally programmable DC-DC converters designed specifically for core power delivery in battery-operated mobile and handheld devices.
FAQ
What is the I²C slave address for FAN53555UC042X?
The FAN53555UC042X uses I²C slave address C4 (hex), which corresponds to 0xC4 (196 decimal). This differs from the base 04 option (C0) and is explicitly documented in Note 2 of the Ordering Information table. The address is hardwired and not software-configurable; proper pull-up on SDA/SCL and correct address matching in host firmware are required for communication with the FAN53555UC042X.
Does FAN53555UC042X reset registers when the EN pin is pulled low?
Yes - the FAN53555UC042X resets all internal registers to their default values when the EN pin is driven LOW. This behavior is specific to the 04, 042, 24, and 79 options and is confirmed in Table 1 and the Operation Description section. Unlike other variants (e.g., 00, 01, 05), the FAN53555UC042X does not retain register state during hardware shutdown, ensuring deterministic boot conditions.
What is the recommended inductor value for FAN53555UC042X in a 5 A application?
The recommended inductor value for FAN53555UC042X at 5 A maximum load is 330 nH, as specified in Table 2 and confirmed in the "Recommended Inductors" section. Vishay IHLP1616ABERR47M01 (470 nH) and Bourns SRP4012-R33M (330 nH) are validated alternatives. Inductor DCR must be ≤20 mΩ, and saturation current rating should exceed 7.4 A (ILIMPK typical) to avoid clipping during transients.
Can FAN53555UC042X operate with only ceramic output capacitors?
Yes - the FAN53555UC042X is fully compatible with low-ESR ceramic output capacitors due to its ESR-independent control architecture. The datasheet specifies two 22 µF, 6.3 V X5R 0805 MLCCs (total 44 µF) as the standard COUT solution. No electrolytic or polymer capacitors are required, simplifying layout and improving reliability in mobile applications.
What is the maximum pulse current capability of FAN53555UC042X?
The FAN53555UC042X supports 5 A continuous output current but does not support the 6.5 A pulse current option - that capability is exclusive to the "05" variant (e.g., FAN53555UC05X). The 042 option retains the standard 5 A continuous rating and 6.3–8.5 A peak current limit (ILIMPK) per Table 10, making it suitable for sustained core rail loads rather than short-duration burst modes.
FAN53555UC042X Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- TinyBuck®
- Package/Case:
- 20-UFBGA, WLCSP
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Last Time Buy
- 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):
- 0.603V
- Voltage - Output (Max):
- 1.41V
- 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)
FAN53555UC042X FAQ
1.How can I place an order for FAN53555UC042X through Aetrix?
Please submit a Request for Quotation (RFQ) for FAN53555UC042X 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 FAN53555UC042X reliable?
The price and inventory of FAN53555UC042X are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FAN53555UC042X is usually 5 days.
3.What payment methods are accepted for FAN53555UC042X?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FAN53555UC042X transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FAN53555UC042X?
FAN53555UC042X orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FAN53555UC042X 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 FAN53555UC042X?
For technical support, including FAN53555UC042X datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FAN53555UC042X requirements.
6.How does Aetrix verify that FAN53555UC042X is sourced from the original manufacturer or authorized distributors?
All FAN53555UC042X 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 FAN53555UC042X meets industry standards.
7.What is the process for return or replacement of FAN53555UC042X?
All FAN53555UC042X units undergo pre-shipment inspection (PSI). If there is an issue with FAN53555UC042X, 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 FAN53555UC042X part is unused and in its original packaging.
Return procedure for FAN53555UC042X:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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