Before diving into electrical specs, it is essential to identify the pins. A proper pinout diagram is always included in the STR F6267 datasheet PDF.
| Pin No. | Symbol | Description | |---------|--------|-------------| | 1 | D (Drain) | Internal MOSFET drain – connected to transformer primary | | 2 | S (Source) | Internal MOSFET source – current sense point | | 3 | VCC | Supply voltage for the control IC (start-up and running) | | 4 | FB (Feedback) | Feedback input from secondary side (via optocoupler) | | 5 | GND | Ground reference for control circuit |
Note: The tab of the TO-220F package is internally connected to the Source (Pin 2). In many designs, the tab is isolated but may be used for heatsinking. str f6267 datasheet pdf
A standard STR-F6267 power supply includes:
Engineers frequently report the following problems when using the STR-F6267: Before diving into electrical specs, it is essential
| Symptom | Likely cause per datasheet | Solution | |------------------------------|-----------------------------------------------------|--------------------------------------------| | No startup, VCC oscillates | VCC startup capacitor too small or leakage | Increase to 47µF, check startup resistor | | Supply shuts down under load | Current sense resistor too large (false OCP) | Reduce resistor value (e.g., 0.33Ω→0.27Ω) | | Blown IC | Drain overvoltage spike exceeding 650V | Improve snubber, check transformer leakage | | Intermittent restart | Overload protection triggered by noise on FB pin | Add 100pF capacitor from FB to GND |
The STR-F6267 is a current-mode PWM (Pulse Width Modulation) controller with a built-in power MOSFET. It is part of Sanken’s STR-F6200 series, designed specifically for flyback converter topologies. The device significantly reduces external component count by integrating the oscillator, control logic, protection circuits, and a high-voltage MOSFET into a single 5-pin TO-220F (fully molded) package. Note: The tab of the TO-220F package is
The STR-F6267 is a hybrid integrated circuit (Hybrid IC) manufactured by Sanken Electric Co., Ltd. It is a current-mode, off-line switching regulator designed specifically for flyback converter topologies. It integrates a power MOSFET and a control IC into a single, compact 5-pin package.
Primary Applications: