My Inquiry
My Account
onsemi FAN5308MPX
- Part No.:
- FAN5308MPX
- Manufacturer:
- onsemi
- Package:
- 6-WDFN Exposed Pad
- Datasheet:
-
FAN5308MPX.pdf
- Description:
- IC REG BUCK ADJ 800MA 6MLP
- Quantity:
- Payment:
- Shipping:
Inventory:4,964
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
FAN5308MPX from onsemi (formerly Fairchild) is a synchronous step-down DC-DC converter IC designed for battery-powered portable electronics. It delivers up to 800mA output current, operates from 2.5V–5.5V input, and supports adjustable output voltage from 0.8V to VIN with 1.3MHz fixed-frequency PWM control and power-save mode.
For engineers reviewing the FAN5308MPX datasheet, pinout, applications, or equivalent options, key selection criteria include its 25µA quiescent current in power-save mode, 96% peak efficiency, 100% duty-cycle low-dropout operation, thermal shutdown at 150°C, and Pb-free 3×3mm 6-lead MLP package compatibility with space-constrained mobile designs.
Technical Context
The FAN5308MPX implements a current-mode PFM/PWM hybrid architecture: it switches automatically between fixed-frequency 1.3MHz PWM mode at moderate-to-heavy loads and variable-frequency pulse-skipping PFM mode at light loads to maintain high efficiency. Dynamic voltage positioning shifts output +0.8% above nominal during transients to preserve regulation headroom.
Its internal control loop integrates error amplification, slope compensation, over-voltage protection, under-voltage lockout (UVLO = 2.1V ±0.2V), and cycle-by-cycle current limiting (1500mA typical). The digital soft-start circuit ramps switch current in four steps to limit inrush, achieving 800µs typical start-up time with 20µF output capacitance and 800mA load.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.5V to 5.5V - supports single-cell Li-ion, Li-poly, or dual-cell alkaline/NiMH battery inputs without external regulators. |
| Output Current | Up to 800mA - sufficient for core logic rails in smartphones, PDAs, and digital cameras. |
| Switching Frequency | 1.3MHz (typical) - enables use of small 3.3µH inductors and ceramic capacitors for compact PCB layouts. |
| Quiescent Current | 25µA (power-save mode) - extends battery runtime in standby/sleep states of portable devices. |
| Reference Voltage | 0.8V (typical) - sets output voltage via external resistor divider (VOUT = 0.8V × (1 + R1/R2)). |
| Efficiency | 96% (peak) - achieved at mid-load with 3.6V input and 1.2V output, minimizing thermal dissipation. |
| Protection Features | Thermal shutdown (150°C), short-circuit current limit (1500mA), output over-voltage protection, UVLO - ensures robust operation under fault conditions. |
Pinout & Package
Packaged in a Pb-free 3×3mm 6-lead MLP (Micro Leadframe Package) with exposed thermal pad (P1/AGND), optimized for thermal performance and board space savings in handheld applications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| P1 (AGND) | Analog Ground | Mandatory solder connection to PCB ground plane; serves as reference for feedback and control circuits. |
| 1 (VIN) | Power Input | Primary supply input (2.5–5.5V); requires local 10µF low-ESR ceramic bypass capacitor. |
| 2 (PGND) | Power Ground | Return path for internal high-side and low-side MOSFETs; must be externally tied to AGND with low-inductance trace. |
| 3 (EN) | Enable Control | Logic-high active enable; pulls supply current below 1µA when low - enables system-level power sequencing. |
| 4 (FB) | Feedback Input | Connects to resistor divider midpoint; regulates output by comparing against 0.8V internal reference. |
| 5 (NC) | No Connection | Unbonded pin - must remain unconnected and unpopulated on PCB. |
| 6 (SW) | Switch Node | Drives external inductor; carries high di/dt switching waveform - requires tight layout with minimal loop area. |
Key Features
| Feature | Design Value |
|---|---|
| Synchronous rectification | Eliminates external Schottky diode, reducing conduction loss and improving efficiency across full load range. |
| Dynamic voltage positioning | Maintains +0.8% output offset in PFM mode to absorb load transients without droop, enabling smaller output capacitance. |
| 100% duty-cycle operation | Allows VOUT ≈ VIN − ILOAD × RDS(ON) when input approaches output, supporting ultra-low dropout in battery-depleted conditions. |
| Digital soft-start | Four-step current ramp limits inrush, preventing input rail collapse and eliminating output overshoot during startup. |
| Thermal shutdown with hysteresis | Shuts down at 150°C and re-enables at 130°C - prevents thermal runaway while allowing safe recovery after cooling. |
Applications
| Smartphone Core Rail | Digital Camera Image Sensor Supply |
|---|---|
Use Scenario: Powering application processor core voltage (e.g., 1.2V @ 800mA) in LTE smartphones during burst data transmission. IC Role / Device Role / Timing Role: Primary point-of-load buck regulator delivering tightly regulated, low-noise DC power with fast transient response. Use Value: 96% efficiency and 25µA quiescent current directly extend talk-time and standby duration; 1.3MHz switching enables compact 3.3µH inductor placement near SoC. | Use Scenario: Supplying programmable analog bias voltage (1.8V–3.3V) to CMOS image sensor pixel array and ADC front-end. IC Role / Device Role / Timing Role: Adjustable-output buck converter providing stable, low-ripple supply independent of battery voltage decay. Use Value: Adjustable 0.8V–VIN range and dynamic voltage positioning ensure consistent sensor SNR across varying lighting conditions and battery states. |
| Portable Media Player Audio Codec | Set-Top Box USB Peripheral Port |
Use Scenario: Generating clean 1.5V supply for high-fidelity audio codec IC in flash-based MP3 players. IC Role / Device Role / Timing Role: Low-noise, high-PSRR DC-DC source decoupled from noisy system rails using ceramic input/output caps. Use Value: Synchronous operation and 1.3MHz frequency minimize EMI coupling into sensitive analog audio paths; soft-start prevents pop/click at power-on. | Use Scenario: Providing 5V/500mA auxiliary power to USB 2.0 host ports in cable/satellite set-top boxes powered from 12V wall adapter. IC Role / Device Role / Timing Role: Secondary buck converter stepping down intermediate 5.5V rail to meet USB spec voltage tolerance (4.75–5.25V). Use Value: 100% duty-cycle capability maintains regulation even as input decays under heavy load; thermal shutdown protects against sustained overcurrent events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down DC-DC converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS62231DRYR | 3MHz switching frequency, 400mA output, 17µA IQ - higher frequency enables smaller passives but lower current rating. | Targeted at ultra-compact wearables; insufficient for 800mA smartphone core rails. | Select only if board space is critical and load current ≤400mA. |
| RT8059GJ6 | 1.5MHz frequency, 600mA output, 30µA IQ, integrated soft-start - lacks dynamic voltage positioning and 100% duty-cycle mode. | Suitable for mid-tier portable devices where transient headroom is less demanding. | Choose when cost sensitivity outweighs need for advanced transient response features. |
Compared with TPS62231DRYR and RT8059GJ6, the FAN5308MPX uniquely combines 800mA capability, 100% duty-cycle operation, and dynamic voltage positioning - making it optimal for battery-powered systems requiring both high current and robust load transient immunity without increasing output capacitance.
Availability
FAN5308MPX is available at Aetrix Electronics and suitable for smartphone core rails, digital camera sensor supplies, portable media player audio codecs, set-top box USB ports, and other battery-powered portable applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for FAN5308MPX 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 (formerly Fairchild Semiconductor) is a global semiconductor supplier focused on energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The FAN5308MPX belongs to onsemi's high-efficiency DC-DC converter product line, engineered specifically for space- and power-constrained portable electronics where extended battery life, small solution size, and reliable transient response are critical design requirements.
FAQ
What is the maximum output current supported by the FAN5308MPX?
The FAN5308MPX supports up to 800mA of continuous output current across its specified input voltage range (2.5V–5.5V) and operating temperature range (−40°C to +85°C ambient). This rating assumes proper PCB thermal design, including adequate copper pour on the AGND pad and appropriate inductor saturation current margin. Peak current limit is internally set to 1500mA for short-circuit protection, but sustained operation above 800mA may trigger thermal shutdown depending on layout and ambient conditions. Always validate thermal performance in the final application.
Does the FAN5308MPX require an external resistor divider for output voltage setting?
Yes, the FAN5308MPX uses an external resistor divider connected to the FB pin to set the output voltage, based on its internal 0.8V reference. The formula is VOUT = 0.8V × (1 + R1/R2), with R1 connected between VOUT and FB, and R2 between FB and AGND. Total resistance (R1 + R2) must be ≤800kΩ to ensure proper bias current; for ultra-low quiescent current designs, R2 = 100kΩ is recommended with a 10pF bypass capacitor across R1. The FAN5308MPX does not support fixed-output variants - all configurations are adjustable.
How does the FAN5308MPX manage efficiency at light loads?
The FAN5308MPX achieves high light-load efficiency through automatic transition into pulse-frequency modulation (PFM) power-save mode. When load current drops below ~150mA (at 3.6VIN/1.2VOUT), it stops switching at fixed frequency and instead delivers energy in discrete pulses, reducing quiescent current to 25µA. During PFM, output voltage is actively regulated with dynamic positioning (+0.8% offset), maintaining transient headroom while minimizing switching losses. This mode eliminates diode reverse-recovery losses and reduces gate-drive energy, distinguishing it from basic skip-mode controllers.
What protection features are integrated into the FAN5308MPX?
The FAN5308MPX integrates five key protection functions: (1) cycle-by-cycle over-current limiting (1500mA typical), (2) thermal shutdown at 150°C with 20°C hysteresis, (3) output over-voltage protection triggered by internal comparator, (4) under-voltage lockout (UVLO) with 2.1V threshold and 150mV hysteresis, and (5) short-circuit foldback limiting average input current to ~200mA during hard faults. These features operate autonomously without external components, ensuring robustness in portable systems subject to battery voltage sag, connector hot-plug events, or accidental shorts.
Can the FAN5308MPX operate with input voltage equal to the desired output voltage?
Yes, the FAN5308MPX supports 100% duty-cycle operation, allowing it to function as a low-dropout linear-like regulator when VIN approaches VOUT. In this mode, the high-side P-channel MOSFET remains continuously on, and VOUT = VIN − ILOAD × (RDS(ON) + RL). With RDS(ON) ≈ 300mΩ at 2.5V gate drive and typical inductor DCR <50mΩ, dropout is under 280mV at 800mA - enabling stable regulation even as lithium battery voltage falls to 3.0V while powering a 2.8V rail. This feature eliminates need for separate LDOs in multi-rail battery systems.
FAN5308MPX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- 6-WDFN Exposed Pad
- 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):
- 0.8V
- Voltage - Output (Max):
- 5.5V
- Current - Output:
- 800mA
- Frequency - Switching:
- 1.3kHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 6-MLP (3x3)
FAN5308MPX FAQ
1.How can I place an order for FAN5308MPX through Aetrix?
Please submit a Request for Quotation (RFQ) for FAN5308MPX 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 FAN5308MPX reliable?
The price and inventory of FAN5308MPX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FAN5308MPX is usually 5 days.
3.What payment methods are accepted for FAN5308MPX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FAN5308MPX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FAN5308MPX?
FAN5308MPX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FAN5308MPX 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 FAN5308MPX?
For technical support, including FAN5308MPX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FAN5308MPX requirements.
6.How does Aetrix verify that FAN5308MPX is sourced from the original manufacturer or authorized distributors?
All FAN5308MPX 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 FAN5308MPX meets industry standards.
7.What is the process for return or replacement of FAN5308MPX?
All FAN5308MPX units undergo pre-shipment inspection (PSI). If there is an issue with FAN5308MPX, 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 FAN5308MPX part is unused and in its original packaging.
Return procedure for FAN5308MPX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
FAN5308MPX 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…
