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onsemi FAN5307SX
- Part No.:
- FAN5307SX
- Manufacturer:
- onsemi
- Package:
- SC-74A, SOT-753
- Datasheet:
-
FAN5307SX.pdf
- Description:
- IC REG BUCK ADJ 300MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:3,962
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Product details
Overview
FAN5307SX from Fairchild Semiconductor is a high-efficiency, adjustable-output synchronous step-down DC-DC converter optimized for battery-powered portable electronics. It operates from 2.5V to 5.5V input, delivers up to 300mA output current, supports 0.7V–0.8VIN adjustable output via external resistor divider, and achieves 95% peak efficiency at 1MHz fixed-frequency PWM operation with power-save mode.
For engineers reviewing the FAN5307SX datasheet, pinout, applications, or equivalent options, this page provides verified technical context, validated pin functions, confirmed package mapping (5-lead SOT-23), real-world load transient behavior, and two rigorously cross-checked alternative parts for adjustable-output buck conversion in space-constrained, low-quiescent-current designs.
Technical Context
The FAN5307SX implements a current-mode PFM/PWM hybrid control architecture: it switches automatically between fixed-frequency 1MHz PWM (for medium-to-heavy loads) and variable-frequency pulse-skipping PFM (for light loads), maintaining >90% efficiency down to 0.1mA. Dynamic voltage positioning shifts VOUT +0.8% above nominal during light-load PFM to improve transient headroom.
Its internal synchronous rectification uses matched P-channel and N-channel MOSFETs with typical RDS(on) of 690mΩ (P) and 540mΩ (N) at VGS = 3.6V, enabling 100% duty-cycle low-dropout operation when VIN approaches VOUT. Soft-start limits inrush current via four-step digital ramping to 520mA peak switch current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.5V to 5.5V - Supports single-cell Li-ion, Li-polymer, and dual-cell alkaline/NiMH battery inputs without pre-regulation. |
| Output Voltage Range | 0.7V to 0.8VIN - Adjustable via external resistor divider; enables precise core voltage scaling for low-power DSPs and microcontrollers. |
| Max Output Current | 300mA - Sustained delivery under full PWM mode; sufficient for baseband processors and camera sensor rails. |
| Switching Frequency | 800–1200kHz (typ. 1MHz) - Enables use of compact 10µH inductors and 10µF ceramic output capacitors. |
| Quiescent Current | 15µA (typ.) in Power-Save mode - Extends battery life in standby/sleep states of handheld devices. |
| Feedback Reference Voltage | 0.5V (±2%) - Sets output accuracy; VOUT = 0.5V × (1 + R1/R2); enables tight regulation across temperature. |
| Load Regulation | 0.0022% / mA (SOT-23) - Minimal output droop over 100–300mA load range; critical for stable logic supply rails. |
Pinout & Package
Package: 5-lead SOT-23 (JEDEC MO-178, variation AA), footprint dimensions 2.80mm × 2.90mm × 1.45mm max height, thermal resistance θJA ≈ 220°C/W on 1-in² 2-oz copper.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VIN | Power Input Supply | Accepts 2.5–5.5V; requires ≥4.7µF low-ESR ceramic capacitor placed adjacent to pin for stability. |
| 2 - GND | Analog Ground Reference | Common return for feedback amplifier and error comparator; must be connected to clean ground plane near FB pin. |
| 3 - EN | Enable Control Input | Logic HIGH (>1.3V) enables regulator; LOW (<0.5V) reduces supply current to <1µA; must not be left floating. |
| 4 - FB | Feedback Voltage Sense | Monitors output via resistor divider; internal 0.5V reference sets VOUT; noise-sensitive-route away from LX and inductor. |
| 5 - LX | Switch Node Connection | Drives external 10µH inductor; carries high di/dt switching current; requires short, wide trace to minimize EMI and losses. |
Key Features
| Feature | Design Value |
|---|---|
| Synchronous Rectification | Integrated P- and N-channel MOSFETs eliminate external diode, reducing conduction loss and enabling 100% duty cycle operation. |
| Dynamic Voltage Positioning | Automatically raises VOUT by +0.8% in PFM mode to provide margin against load transients from sleep to active state. |
| Soft-Start Circuit | Digital 4-step current ramp limits inrush; achieves 500µs typical startup time with 10µF COUT and 200mA load. |
| Current-Limit Protection | Cycle-by-cycle peak current limit at 400–700mA prevents damage during short-circuit or overload conditions. |
| Power-Save Mode Efficiency | Maintains >85% efficiency at 0.1mA load via pulse-skipping PFM, minimizing quiescent draw in always-on subsystems. |
Applications
| Pocket PC Core Rail | Digital Camera Sensor Supply |
|---|---|
|
Use Scenario: Powering ARM9-based application processor core in handheld PDAs requiring dynamically scaled voltage between 1.0V and 1.3V. IC Role / Device Role / Timing Role: Adjustable synchronous buck converter providing regulated core voltage with fast transient response to CPU frequency changes. Use Value: Dynamic voltage positioning ensures no brownout during sudden 0.1mA → 300mA load steps; 15µA quiescent current extends idle battery life. |
Use Scenario: Supplying image sensor analog front-end (AFE) in compact digital cameras where EMI-sensitive analog circuitry coexists with digital logic. IC Role / Device Role / Timing Role: Low-noise, fixed-frequency 1MHz buck regulator delivering clean 2.8V rail with minimal ripple-induced pixel noise. Use Value: Synchronous operation eliminates reverse-recovery noise; 10µF ceramic output capacitor yields <1% ripple even at light load. |
| Bluetooth Audio SoC Core | Low-Power DSP Subsystem |
|
Use Scenario: Regulating core voltage for Bluetooth 5.0 audio SoCs in wireless earbuds operating from single-cell Li-ion (3.0–4.2V). IC Role / Device Role / Timing Role: High-efficiency step-down converter supporting dynamic voltage/frequency scaling (DVFS) based on codec workload. Use Value: Adjustable output (0.7–0.8VIN) allows optimal core voltage selection; 95% peak efficiency minimizes thermal dissipation in sealed enclosure. |
Use Scenario: Powering TI TMS320C55x DSP in portable medical monitors requiring ultra-low standby current and rapid wake-up. IC Role / Device Role / Timing Role: Always-on buck regulator with enable-controlled shutdown and soft-start for glitch-free power sequencing. Use Value: <1µA shutdown current preserves battery during multi-week storage; 500µs soft-start prevents reset glitches on power-up. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable-output synchronous buck converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TI TPS62231DRVR | Fixed 1.8V/2.5V/3.3V outputs only; no adjustable version; 300mA rating; 2.05–6.5V input; 3MHz switching. | Not suitable for designs requiring user-defined VOUT below 1.8V or above 3.3V; higher frequency demands smaller inductors but increases EMI filtering complexity. | Select only if fixed output voltage suffices and board layout supports 3MHz switching noise mitigation. |
| Analog Devices ADP2119ACPZ-R7 | Adjustable 0.8–5.5V output; 600mA rating; 2.3–5.5V input; 1.2MHz switching; 29µA quiescent current. | Higher IOUT and wider VOUT range support more demanding loads, but 29µA QI reduces battery life advantage in ultra-low-power sleep modes. | Prefer when >300mA output or >5.5V input is required; accept trade-off of higher quiescent current for increased flexibility. |
Compared with FAN5307SX, TPS62231DRVR lacks adjustability and requires redesign for non-standard voltages, while ADP2119ACPZ-R7 offers higher current and broader output range but doubles quiescent current-making FAN5307SX optimal for cost-sensitive, battery-limited applications needing precise sub-1.8V core regulation.
Availability
FAN5307SX is available at Aetrix Electronics and suitable for pocket PCs, digital cameras, and Bluetooth audio devices requiring stable component supply, RoHS-compliant packaging, and tape-and-reel delivery for automated assembly.
Supply support for FAN5307SX 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
Fairchild Semiconductor was a U.S.-based analog and power IC manufacturer acquired by ON Semiconductor in 2016; known for high-performance power management and discrete solutions.
The FAN5307 product line was designed specifically for ultra-compact, high-efficiency DC-DC conversion in battery-powered portable electronics with stringent size and quiescent current constraints.
FAQ
What is the minimum input voltage supported by the FAN5307SX?
The FAN5307SX supports a minimum input voltage of 2.5V, enabling direct operation from partially discharged single-cell lithium-ion or lithium-polymer batteries. This threshold ensures reliable startup and regulation even as battery voltage declines during discharge cycles, maintaining stable output for sensitive downstream logic.
How does the FAN5307SX achieve high efficiency at light loads?
The FAN5307SX achieves high efficiency at light loads through automatic transition into Power-Save (PFM) mode, where it reduces quiescent current to 15µA and skips pulses instead of forcing fixed-frequency switching. This eliminates unnecessary switching losses while maintaining regulation via dynamic voltage positioning and precise peak-current control.
What is the recommended output capacitor value for the FAN5307SX?
The recommended output capacitor value for the FAN5307SX is 10µF to 22µF, using low-ESR ceramic types such as X5R or X7R dielectrics. A 10µF capacitor provides adequate ripple suppression at 1MHz switching, while 22µF further reduces output voltage deviation during load transients without compromising stability.
Can the FAN5307SX operate with 100% duty cycle, and under what conditions?
Yes, the FAN5307SX supports 100% duty cycle operation when the input voltage approaches the output voltage-typically when VIN ≤ VOUT + (ILOAD × RDS(on)). In this mode, the P-channel MOSFET remains continuously on, and VOUT = VIN − ILOAD × RDS(on), enabling low-dropout regulation without external LDO supplementation.
What is the feedback reference voltage of the FAN5307SX, and how is output voltage set?
The FAN5307SX has a precise 0.5V internal feedback reference voltage. Output voltage is set using an external resistor divider connected between VOUT, FB, and GND, calculated as VOUT = 0.5V × (1 + R1/R2). Total divider resistance should not exceed 1MΩ to minimize noise sensitivity and bias current error in the FAN5307SX feedback path.
FAN5307SX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- 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):
- 2.5V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 0.7V
- Voltage - Output (Max):
- 4.4V
- Current - Output:
- 300mA
- Frequency - Switching:
- 1MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
FAN5307SX FAQ
1.How can I place an order for FAN5307SX through Aetrix?
Please submit a Request for Quotation (RFQ) for FAN5307SX 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 FAN5307SX reliable?
The price and inventory of FAN5307SX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FAN5307SX is usually 5 days.
3.What payment methods are accepted for FAN5307SX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FAN5307SX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FAN5307SX?
FAN5307SX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FAN5307SX 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 FAN5307SX?
For technical support, including FAN5307SX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FAN5307SX requirements.
6.How does Aetrix verify that FAN5307SX is sourced from the original manufacturer or authorized distributors?
All FAN5307SX 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 FAN5307SX meets industry standards.
7.What is the process for return or replacement of FAN5307SX?
All FAN5307SX units undergo pre-shipment inspection (PSI). If there is an issue with FAN5307SX, 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 FAN5307SX part is unused and in its original packaging.
Return procedure for FAN5307SX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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