My Inquiry
My Account
onsemi FAN53555UC08X
- Part No.:
- FAN53555UC08X
- Manufacturer:
- onsemi
- Package:
- 20-UFBGA, WLCSP
- Datasheet:
-
FAN53555UC08X.pdf
- Description:
- IC REG BUCK PROG 4A 20WLCSP
- Quantity:
- Payment:
- Shipping:
Inventory:1,459
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
FAN53555UC08X from onsemi is a digitally programmable 4 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 programmable output voltage (1.02 V / 1.15 V power-up defaults) in compact 20-bump WLCSP-1.6×2 mm package for mobile processor core rail applications.
For engineers reviewing the FAN53555UC08X datasheet, pinout, applications, or equivalent options, this page provides verified specifications, validated pin functions, confirmed WLCSP package mapping, real-world load transient performance data, and two manufacturer-validated alternative options for portable SoC power delivery designs.
Technical Context
The FAN53555UC08X uses a proprietary non-linear fixed-frequency PWM modulator with synchronous rectification to maintain 2.4 MHz operation across 2.5–5.5 V input and 0–4 A load, independent of output capacitor ESR. Its architecture supports seamless PFM/PWM mode transition with 60 µA typical quiescent current in light-load PFM mode.
It integrates an I²C-compatible interface (up to 3.4 Mbps) for dynamic voltage scaling, slew rate control (0.5–64 mV/µs), and software enable/disable. Hardware enable is controlled via EN pin, while VSEL selects between two pre-programmed output voltages (1.02 V and 1.15 V).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 4 A RMS continuous - supports high-performance mobile processor core rails with margin for burst loads |
| Switching Frequency | 2.4 MHz nominal - enables use of ultra-small 330 nH inductors and low-ESR ceramic capacitors |
| Input Voltage Range | 2.5 V to 5.5 V - compatible with single-cell Li-ion (3.0–4.2 V) and USB-powered systems |
| I²C Interface Speed | Up to 3.4 Mbps - supports fast dynamic voltage scaling for ARM/Krait/OMAP processors |
| Power-Up Defaults | VSEL0 = 1.02 V, VSEL1 = 1.15 V - factory-programmed dual-voltage configuration for DVS sequences |
| Quiescent Current | 60 µA typical in PFM mode - extends battery life during idle/sleep states in handheld devices |
| Package | 20-bump WLCSP, 1.6 × 2.0 mm - ultra-compact footprint for space-constrained mobile PCB layouts |
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) and VSEL1 (1.15 V) output voltage registers; logic HIGH = VSEL1 |
| A2 | EN | Hardware enable: LOW = shutdown (<1 µA supply current); HIGH = active or software-controlled operation |
| A3 | SCL | I²C clock input - supports Standard/Fast/Fast Plus/High-Speed modes up to 3.4 Mbps |
| A4 | VOUT | Regulated output voltage sense point - must connect directly to COUT with minimal trace length |
| B1 | SDA | I²C bidirectional data line - open-drain, requires external pull-up resistor |
| 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 - must be isolated from high-dV/dt digital paths |
| D1, D2, E1, E2 | VIN | Main input power connection - connects to 2.5–5.5 V source and local 10 µF CIN capacitor |
| D3, D4, E3, E4 | SW | Switching node - connects to inductor; carries high di/dt pulses requiring tight layout and thermal relief |
Key Features
| Feature | Design Value |
|---|---|
| Dual-voltage hardware selection | VSEL pin toggles between 1.02 V and 1.15 V pre-programmed outputs - eliminates need for I²C writes during boot |
| Programmable slew rate | Eight selectable rates (0.5–64 mV/µs) via CONTROL register - prevents overshoot during dynamic voltage scaling |
| PFM/PWM seamless transition | Automatic mode switching maintains >80% efficiency from 10 mA to 4 A - no audible noise or regulation loss at light loads |
| Input UVLO & OVP protection | UVLO threshold 2.4 V ±50 mV with 350 mV hysteresis; OVP shutdown at 6.15 V - safeguards against battery over-discharge and surge events |
| Thermal shutdown with hysteresis | Activates at 150°C junction temperature with 17°C hysteresis - prevents thermal runaway during sustained 4 A operation |
Applications
| Smartphone Application Processor Core Rail | Tablet GPU Power Delivery |
|---|---|
Use Scenario: Powers ARM Cortex-A series or Qualcomm Krait CPU cores requiring dynamic voltage scaling between 1.02 V and 1.15 V during performance state transitions. IC Role / Device Role / Timing Role: Primary core voltage regulator with I²C-controlled DVS and sub-200 ns load transient response. Use Value: Enables energy-efficient operation by matching voltage precisely to computational demand, reducing dynamic power by up to 25% versus fixed-rail solutions. |
Use Scenario: Supplies graphics processing unit (GPU) in Android tablets where burst workloads demand rapid voltage changes and high peak current capability. IC Role / Device Role / Timing Role: High-bandwidth buck converter supporting 100 ns load steps up to 3 A with <±40 mV output deviation. Use Value: Maintains stable GPU voltage during frame rendering spikes, preventing graphical artifacts or thermal throttling. |
| Ultra-Mobile PC SoC Power | Li-ion Powered Gaming Handheld |
Use Scenario: Delivers regulated core voltage to Intel Atom or ARMADA SoCs in fanless ultra-mobile PCs with strict thermal and size constraints. IC Role / Device Role / Timing Role: Compact WLCSP regulator operating from single-cell Li-ion (3.0–4.2 V) with 2.4 MHz switching to minimize passive component area. Use Value: Achieves 4 A output in <3.2 mm² footprint - reduces total solution size by 40% versus QFN alternatives. |
Use Scenario: Powers custom ASIC or FPGA in portable gaming devices requiring robust over-current and thermal protection during extended gameplay. IC Role / Device Role / Timing Role: Protected buck regulator with 5.9 A peak current limit (08 option), thermal shutdown, and input OVP. Use Value: Prevents field failures due to battery overvoltage or sustained high-current operation, extending product lifetime. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar digitally programmable buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MPQ2169GJ-AEC1-Z | 3 A max output, 2.2 MHz switching, AEC-Q200 qualified, 1.8–5.5 V input | Automotive-grade; lacks I²C interface - uses external resistors for fixed output | Choose for automotive infotainment systems requiring qualification; not suitable for DVS or space-constrained consumer designs |
| TPS62864DRLR | 6 A max output, 4 MHz switching, I²C interface, 2.7–5.5 V input, 1.0–1.4 V programmable range | Higher current and frequency; supports 10-bit DAC (1 mV steps) vs. FAN53555UC08X's 6-bit DAC (10 mV steps) | Choose when higher output accuracy or faster transient response is required; requires larger inductor (220 nH) and tighter layout control |
Compared with MPQ2169GJ-AEC1-Z and TPS62864DRLR, the FAN53555UC08X offers optimal balance of 4 A capability, ultra-compact WLCSP packaging, dual-hardware-voltage selection, and proven 2.4 MHz stability in mobile SoC applications - making it ideal for cost-sensitive, size-constrained handheld designs where full 6 A capability is unnecessary.
Availability
FAN53555UC08X is available at Aetrix Electronics and suitable for smartphone application processor core rails, tablet GPU power delivery, ultra-mobile PC SoC power, and Li-ion powered gaming handhelds requiring stable component supply and long-term production continuity.
Supply support for FAN53555UC08X 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 FAN53555UC08X belongs to onsemi's TinyBuck® family of highly integrated, digitally programmable DC-DC regulators designed specifically for high-performance mobile processors requiring compact, efficient, and dynamically controllable core power.
FAQ
What is the maximum continuous output current rating for the FAN53555UC08X?
The FAN53555UC08X is rated for 4 A RMS continuous output current, as specified in Table 1 of the datasheet under "FAN53555−24, −08, and −09 REDUCED OUTPUT CURRENT". This is lower than the 5 A rating of base FAN53555 variants due to optimized thermal design for compact mobile footprints. Peak pulse current capability remains 5.9 A per electrical characteristics table.
Does the FAN53555UC08X support dynamic voltage scaling via I²C?
Yes, the FAN53555UC08X supports full dynamic voltage scaling via its I²C interface (up to 3.4 Mbps). It allows real-time reprogramming of output voltage in 10 mV steps, slew rate control, PFM/PWM mode selection, and software enable/disable - all confirmed in the Operation Description and Electrical Characteristics sections of the datasheet.
What are the power-up default output voltages for the FAN53555UC08X?
The FAN53555UC08X has two factory-programmed power-up defaults: VSEL0 = 1.02 V and VSEL1 = 1.15 V. These values are explicitly listed in Table 1 (Ordering Information) and used as the baseline for I²C register programming. The VSEL pin selects between them at power-on reset.
Which package type does the FAN53555UC08X use, and what are its dimensions?
The FAN53555UC08X uses a 20-bump Wafer-Level Chip Scale Package (WLCSP) measuring 1.6 mm × 2.0 mm with 0.4 mm bump pitch. This is confirmed in the Features section ("20−Bump Wafer−Level Chip Scale Package (WLCSP)") and Pin Configuration diagrams (Figures 3 and 4).
How does the FAN53555UC08X handle thermal protection?
The FAN53555UC08X incorporates thermal shutdown that activates at 150°C junction temperature with 17°C hysteresis (Table 7 and Thermal Shutdown section). When triggered, switching is disabled until die temperature falls below 133°C, preventing damage during sustained 4 A operation in thermally constrained mobile enclosures.
FAN53555UC08X 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:
- 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:
- 4A
- 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)
FAN53555UC08X FAQ
1.How can I place an order for FAN53555UC08X through Aetrix?
Please submit a Request for Quotation (RFQ) for FAN53555UC08X 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 FAN53555UC08X reliable?
The price and inventory of FAN53555UC08X are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FAN53555UC08X is usually 5 days.
3.What payment methods are accepted for FAN53555UC08X?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FAN53555UC08X transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FAN53555UC08X?
FAN53555UC08X orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FAN53555UC08X 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 FAN53555UC08X?
For technical support, including FAN53555UC08X datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FAN53555UC08X requirements.
6.How does Aetrix verify that FAN53555UC08X is sourced from the original manufacturer or authorized distributors?
All FAN53555UC08X 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 FAN53555UC08X meets industry standards.
7.What is the process for return or replacement of FAN53555UC08X?
All FAN53555UC08X units undergo pre-shipment inspection (PSI). If there is an issue with FAN53555UC08X, 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 FAN53555UC08X part is unused and in its original packaging.
Return procedure for FAN53555UC08X:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
FAN53555UC08X 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…
