UC3845BN datasheet by STMicroelectronics

UC3845BN Frequently Asked Questions (FAQs)

• What is the maximum operating frequency of the UC3845BN?
  The UC3845BN can operate up to 500 kHz, but the recommended operating frequency is up to 400 kHz for optimal performance.
• How do I ensure stable operation of the UC3845BN?
  To ensure stable operation, make sure to decouple the VCC pin with a 10nF to 100nF capacitor, and use a low-ESR output capacitor. Also, ensure that the input voltage is within the recommended range and the device is properly heatsinked.
• What is the purpose of the soft-start pin (SS) on the UC3845BN?
  The soft-start pin (SS) is used to slowly ramp up the output voltage during startup, reducing inrush currents and electromagnetic interference (EMI). It can be connected to a capacitor to ground to set the soft-start time.
• How do I adjust the output voltage of the UC3845BN?
  The output voltage of the UC3845BN can be adjusted by using a resistive divider network between the output and the feedback pin (FB). The ratio of the resistors determines the output voltage.
• What is the maximum output current of the UC3845BN?
  The maximum output current of the UC3845BN depends on the specific application and the transformer turns ratio. However, the device can deliver up to 1A peak current.