1. Product Identification & Overview

️· Product: FSP3133
️· Type: PWM Control DC/DC Converter
️· Function: A step-down (buck) converter that regulates voltage using PWM.
️· Target Applications: General-purpose DC/DC conversion.
️· Key Features:
- Broad input voltage range (3.6V to 23V).
- Adjustable Output Voltage (using external resistors).
- Built-in protection features: Under Voltage Lockout (UVLO), Current Limiting (through external resistor).
- Soft-start functionality.
- Efficiency up to 92%.

2. Key Electrical Specifications (Typical Values)

️· Input Voltage (VIN): 3.6V - 23V
️· Output Voltage (VOUT): Adjustable, with example configurations for 2.5V, 3.3V, and 5V. The formula for calculating the output voltage is: VOUT = VFB * (1 + RA / RB) (where RA and RB are external resistors)
️· Output Current (IOUT): Up to 2A
️· Switching Frequency (fosc): 240kHz - 360kHz (typical 300kHz)
️· Current Limit Frequency (fosc1): 10kHz
️· Feedback Bias Current (IFB): 0.1µA – 0.5µA
️· Internal MOSFET Rdson: 70mΩ - 150mΩ (depending on voltage)
️· Soft-Start Time (TSS): 0.3ms - 2ms
️· Enable Voltage (VSH/VSL): 2.0V / 0.8V.

3. Functional Description & Operation

️· PWM Control: The converter regulates the output voltage by adjusting the pulse width of the switching signal.
️· Under Voltage Lockout (UVLO): Shuts down the converter when the input voltage drops below a threshold (3.3V) to prevent damage.
️· Current Limiting: Prevents excessive current draw, protecting the MOSFET and load. The current limit is set by an external resistor.
️· Soft Start: Gradually increases the output voltage to reduce inrush current and stress on components.

4. Ordering Information & Marking

️· Ordering Code: FSP3133XXXX (XXXX represents the specific configuration options)
️· Package Options: SOP8L
️· Output Voltage Adjustment: Can be adjusted by changing the feedback resistors (blank represents ADJ).
️· Temperature Grade: G (-20°C to 125°C)
️· Marking: Includes the part number, date code (YYWWXX - Year, Week).

5. Package Dimensions (SOP8L)

️· Detailed dimensional specifications are provided in millimeters and inches. This would include dimensions like A, A1, A2, B, C, D, E, H, L, and θ.

IMPORTANT NOTES & LIMITATIONS:

️· Data Consistency: Datasheets sometimes have conflicting or unclear information. I've tried to extract the most common values, but double-check with the official datasheet for critical design parameters.
️· Incomplete Information: This is a summary, and it doesn't contain *every* detail from the datasheet. Refer to the full document for complete specifications and application notes.
️· Resistance Values: The document mentions the resistor values (RA and RB) but does not provide a complete calculation to set the output voltage.
️· Design Considerations: The datasheet provides a starting point, but proper design requires careful consideration of component selection, layout, and thermal management.
️· Date: The datasheet is dated 2007-6-22, so some aspects of the design might be outdated. Check for newer revisions.