The current sense resistor ( R_sense ) is calculated based on the desired peak primary current: [ R_sense = \fracV_OCP(th)I_ppk ] Where ( V_OCP(th) ) is typically 0.73V. The datasheet recommends using a non-inductive resistor for accurate sensing.
Because the STR W6553A operates in current-mode control, the transformer must be designed to avoid subharmonic oscillation. A slope compensation network is not required internally, but the datasheet provides guidelines for selecting primary inductance (typically 0.5mH to 2mH depending on power level). str w6553a datasheet
The STR W6553A datasheet includes information on the IC's package and pinout. The IC is available in a 24-pin DIP package, which provides a compact and rugged design. The pinout diagram shows the location of each pin and its function, making it easy for designers to connect the IC to external components. The current sense resistor ( R_sense ) is
A 10µF to 47µF electrolytic capacitor is recommended near the VCC pin. This capacitor must hold enough charge during startup and transient loading. Place it as close as possible to pins 3 and 4. A slope compensation network is not required internally,
Automatically switches between quasi-resonant mode for normal operation and a Burst Standby mode for light loads to minimize power consumption.
The IC typically comes in a or Zip 7-pin package. Understanding its pin functions is critical for troubleshooting and circuit design: Description 1 D (Drain)
Was this article helpful? YES NO
ACTIVE Network, LLC
Three Alliance Center, 29th Fl.
3550 Lenox Rd. #3000, Atlanta GA 30326, US
