My Inquiry
My Account
onsemi FAN53555BUC09X
- Part No.:
- FAN53555BUC09X
- Manufacturer:
- onsemi
- Package:
- 20-UFBGA, WLCSP
- Datasheet:
-
FAN53555BUC09X.pdf
- Description:
- IC REG BUCK PROG 3A 20WLCSP
- Quantity:
- Payment:
- Shipping:
Inventory:4,408
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
FAN53555BUC09X from onsemi is a digitally programmable 3 A synchronous step-down DC-DC regulator delivering 0.603–1.411 V output in 12.826 mV steps via I²C interface, operating from 2.5–5.5 V input at 2.4 MHz fixed frequency with PFM/PWM auto-mode switching-designed for core voltage regulation in mobile application processors.
For engineers reviewing the FAN53555BUC09X datasheet, pinout, applications, or equivalent options, key selection criteria include its 3 A RMS current rating, 12.826 mV DAC resolution, 60 µA quiescent current in PFM mode, WLCSP-20 package footprint, and I²C-compatible 3.4 Mbps interface for dynamic voltage scaling in space-constrained handheld devices.
Technical Context
The FAN53555BUC09X employs a proprietary non-linear fixed-frequency PWM modulator with synchronous rectification, maintaining 2.4 MHz switching across load and input voltage variations while enabling ceramic capacitor compatibility independent of ESR. Its control architecture supports seamless PFM-to-PWM transition with single-pulse light-load operation.
It integrates hardware enable (EN), voltage-select logic (VSEL), and I²C registers for real-time configuration-including slew-rate programmability (0.5–64 mV/µs), MODE bit control to force PWM, and BUCK_EN bits for software enable. Input under-voltage lockout (2.45 V threshold) and over-voltage protection (6.15 V shutdown) are implemented with internal hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 3 A RMS continuous - defines maximum sustained load capability for processor core rails without thermal derating in typical handheld PCB layouts. |
| Input Voltage Range | 2.5 V to 5.5 V - supports direct Li-ion battery (3.0–4.2 V) and regulated 3.3 V/5 V system rails without intermediate pre-regulation. |
| Switching Frequency | 2.4 MHz nominal - enables use of ultra-small 330 nH inductors and 22 µF X5R 0603 capacitors, minimizing solution footprint. |
| I²C Interface Speed | Up to 3.4 Mbps - allows rapid dynamic voltage scaling during CPU DVFS transitions with sub-100 µs register update latency. |
| Output Voltage Range | 0.603 V to 1.411 V in 12.826 mV steps - matches ARM/Krait core voltage requirements with fine-grained DVS resolution for power optimization. |
| Quiescent Current | 60 µA typical in PFM mode - sustains >100-hour standby battery life in always-on subsystems without compromising transient response. |
| Package | 20-bump WLCSP, 1.6 × 2.0 mm - provides <0.4 mm profile and minimal thermal resistance (θJA = 38°C/W) for thin mobile form factors. |
Pinout & Package
Package: 20-bump Wafer-Level Chip Scale Package (WLCSP), 1.6 mm × 2.0 mm, 0.4 mm height, bottom-side solder bumps.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A1 | VSEL | Voltage select logic input - LOW selects VSEL0 register value; HIGH selects VSEL1 register value; determines default output voltage at power-up (1.10 V for FAN53555BUC09X). |
| A2 | EN | Hardware enable - device enters shutdown (<0.5 µA supply current) when pulled LOW; retains register state during shutdown per option-specific behavior. |
| A3 | SCL | I²C serial clock input - supports Standard (100 kHz), Fast (400 kHz), Fast Plus (1 MHz), and High-Speed (3.4 Mbps) modes with programmable timing. |
| A4 | VOUT | Output voltage sense node - connects directly to output capacitor bank; used for feedback regulation and PGOOD assertion (not present on this variant). |
| B1 | SDA | I²C bidirectional data line - open-drain structure requires external pull-up; supports full read/write access to all configuration registers including VSEL0/VSEL1 and CONTROL. |
| B2, B3, C1–C4 | GND | Power ground - low-side MOSFET source reference and primary return path for input/output capacitors; must be connected with minimal impedance. |
| B4 | AGND | Analog ground - reference for internal error amplifier and ADC; isolated from high-dV/dt digital paths to maintain regulation accuracy. |
| D1, D2, E1, E2 | VIN | Input power supply - accepts 2.5–5.5 V; requires local 10 µF X5R 0402 ceramic capacitor placed within 2 mm of pins to suppress high-frequency ripple. |
| D3, D4, E3, E4 | SW | Switching node - connects to inductor; carries high di/dt pulses; layout requires short, wide copper trace to minimize EMI and switching losses. |
Key Features
| Feature | Design Value |
|---|---|
| Digitally programmable output | 0.603–1.411 V in precise 12.826 mV steps via I²C - enables exact matching to ARM/Krait core voltage tables without external resistor networks. |
| PFM/PWM auto-mode switching | 60 µA quiescent current at light load + seamless transition to 2.4 MHz PWM at >300 mA - maintains >80% efficiency from 10 mA to 3 A without manual mode control. |
| Programmable slew rate | Eight selectable rates (0.5–64 mV/µs) via CONTROL register - prevents overshoot/undershoot during DVFS transitions and reduces EMI during voltage ramps. |
| Integrated protections | UVLO (2.45 V), OVP (6.15 V), thermal shutdown (150°C), and peak current limiting (4.75 A) - eliminates need for external fault management circuitry. |
| Soft-start with pre-bias support | Internal ramp generator + synchronous rectification inhibition during startup - allows safe start into pre-charged output capacitors up to 220 µF. |
Applications
| Smartphone Application Processor Core Rail | Tablet GPU Voltage Scaling |
|---|---|
Use Scenario: Powers ARM Cortex-A series CPU cores in LTE smartphones with dynamic frequency scaling between 0.6–1.4 V based on workload. IC Role / Device Role / Timing Role: Primary core voltage regulator with I²C-controlled DVS responding to SoC PMIC commands within 50 µs. Use Value: Enables 30% active power reduction during idle states while sustaining 3 A burst current for camera/AI acceleration without voltage droop. |
Use Scenario: Supplies Mali or Adreno GPU cores in Android tablets requiring fast voltage transitions during graphics rendering bursts. IC Role / Device Role / Timing Role: Synchronous buck converter with programmable slew rate to prevent GPU reset during 0.8 V ↔ 1.2 V transitions. Use Value: Delivers 2.4 MHz switching stability with 22 µF 0603 output caps, reducing total solution area by 40% vs. legacy 500 kHz regulators. |
| Ultra-Mobile PC SoC I/O Domain | Connected Wearable Sensor Hub |
Use Scenario: Regulates I/O voltage domain (1.05–1.2 V) for Intel Atom or Qualcomm Snapdragon SoCs in fanless UMPCs. IC Role / Device Role / Timing Role: Digitally programmable point-of-load regulator with hardware EN and VSEL pin override for boot sequence coordination. Use Value: Maintains ±2% output accuracy across −40°C to +85°C ambient while drawing only 60 µA in sleep mode for multi-day battery life. |
Use Scenario: Powers low-power sensor fusion hub (accelerometer, gyro, environmental sensors) in Bluetooth earbuds with tight size constraints. IC Role / Device Role / Timing Role: Compact 1.6 × 2.0 mm WLCSP regulator supporting 0.6–1.1 V range with minimal external components (1 inductor, 2 caps). Use Value: Achieves 88% peak efficiency at 100 mA load using 330 nH inductor and 22 µF 0603 cap, extending battery runtime by 22% vs. LDO solutions. |
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 |
|---|---|---|---|
| TPS62864DLCR | 2.5–5.5 V input, 4 A, 2.4 MHz, I²C interface, 0.3–1.4 V output in 10 mV steps, 1.21 mm × 0.81 mm DSBGA | Higher current rating (4 A) and finer DAC resolution (10 mV), but larger package pitch (0.35 mm vs. 0.4 mm bump spacing) and no VSEL pin override | Select when higher sustained current or tighter voltage granularity is required; verify PCB pad layout compatibility with smaller ball pitch |
| RTQ2132BGQW | 2.7–5.5 V input, 3 A, 2.2 MHz, I²C interface, 0.5–1.52 V output in 12.5 mV steps, 1.62 mm × 2.13 mm WLCSP | Similar current and footprint, but lower switching frequency (2.2 MHz) and wider input range; lacks programmable slew rate control | Choose for cost-sensitive designs where 200 kHz frequency margin and absence of slew control are acceptable trade-offs |
Compared with TPS62864DLCR and RTQ2132BGQW, the FAN53555BUC09X offers unique VSEL pin hardware override for boot-time voltage selection, integrated 12.826 mV-step DAC optimized for ARM core tables, and proven 3 A thermal performance in 1.6 × 2.0 mm WLCSP-making it optimal for space-constrained mobile SoC core rails requiring both digital flexibility and hardware fallback.
Availability
FAN53555BUC09X is available at Aetrix Electronics and suitable for smartphone application processor core rails, tablet GPU voltage scaling, and ultra-mobile PC SoC I/O domains requiring stable component supply with guaranteed long-term availability.
Supply support for FAN53555BUC09X 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 silicon solutions for automotive, industrial, cloud, medical, and IoT applications-with focus on power management, analog, sensors, and connectivity.
The FAN53555BUC09X belongs to onsemi's TinyBuck® family of ultra-compact, high-efficiency DC-DC regulators designed specifically for core voltage delivery in battery-powered mobile processors where size, efficiency, and digital controllability are critical.
FAQ
What is the default output voltage of the FAN53555BUC09X at power-up?
The FAN53555BUC09X powers up with a default output voltage of 1.10 V when the VSEL pin is HIGH, corresponding to the VSEL1 register value specified in Table 1 of the datasheet. This setting is factory-programmed and remains stable across temperature and input voltage variations within the 2.5–5.5 V range. The FAN53555BUC09X supports reprogramming via I²C to any value between 0.603 V and 1.411 V in 12.826 mV increments.
Does the FAN53555BUC09X support forced PWM mode to eliminate frequency variation?
Yes, the FAN53555BUC09X supports forced PWM mode via the MODE bit in the VSEL registers. When set HIGH, the regulator disables PFM operation and maintains strict 2.4 MHz switching regardless of load current-ensuring predictable EMI profiles and consistent loop response during sensitive analog measurements. In this mode, quiescent current increases to 43 mA, but light-load efficiency remains above 75% down to 10 mA.
What is the maximum pulse current capability of the FAN53555BUC09X?
The FAN53555BUC09X is rated for 3 A RMS continuous output current, with a peak pulse current limit of 4.75 A (typical) as defined by its ILIMPK specification. This limit activates after 16 consecutive current-limit cycles, triggering thermal-foldback and automatic restart after 1700 µs. Unlike the FAN53555BUC05X (6.5 A pulse), the FAN53555BUC09X is optimized for balanced efficiency and thermal performance in mid-power mobile applications.
Can the FAN53555BUC09X be used with ceramic output capacitors?
Yes, the FAN53555BUC09X is explicitly designed for ceramic output capacitors, requiring no ESR-based compensation. Its proprietary control architecture maintains stability with low-ESR X5R/X7R types such as 22 µF 0603 capacitors. The datasheet recommends two 22 µF 0603 parts (total 44 µF) for optimal transient response, and confirms stability even with up to 220 µF total capacitance when soft-start parameters are adjusted accordingly.
Is the FAN53555BUC09X pin-compatible with other variants in the FAN53555 family?
Yes, all FAN53555 variants-including FAN53555BUC09X-share identical 20-bump WLCSP-20 packaging, pinout, and footprint. Hardware connections (VIN, SW, VOUT, GND, AGND, EN, VSEL, SCL, SDA) are functionally identical across the family. Differences are limited to internal register defaults, current ratings, and DAC step sizes-enabling drop-in replacement during design iteration without PCB changes.
FAN53555BUC09X 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):
- 0.603V
- Voltage - Output (Max):
- 1.41V
- Current - Output:
- 3A
- 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)
FAN53555BUC09X FAQ
1.How can I place an order for FAN53555BUC09X through Aetrix?
Please submit a Request for Quotation (RFQ) for FAN53555BUC09X 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 FAN53555BUC09X reliable?
The price and inventory of FAN53555BUC09X are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FAN53555BUC09X is usually 5 days.
3.What payment methods are accepted for FAN53555BUC09X?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FAN53555BUC09X transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FAN53555BUC09X?
FAN53555BUC09X orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FAN53555BUC09X 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 FAN53555BUC09X?
For technical support, including FAN53555BUC09X datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FAN53555BUC09X requirements.
6.How does Aetrix verify that FAN53555BUC09X is sourced from the original manufacturer or authorized distributors?
All FAN53555BUC09X 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 FAN53555BUC09X meets industry standards.
7.What is the process for return or replacement of FAN53555BUC09X?
All FAN53555BUC09X units undergo pre-shipment inspection (PSI). If there is an issue with FAN53555BUC09X, 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 FAN53555BUC09X part is unused and in its original packaging.
Return procedure for FAN53555BUC09X:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
FAN53555BUC09X 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
Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…
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…
