SG3525AN datasheet by STMicroelectronics

SG3525AN Frequently Asked Questions (FAQs)

• What is the maximum voltage rating for the SG3525AN?
  The maximum voltage rating for the SG3525AN is 40V, but it's recommended to operate it within 30V to ensure reliable operation.
• How do I choose the right values for the timing resistors (RT) and capacitors (CT) for the oscillator?
  The values of RT and CT depend on the desired oscillator frequency. A good starting point is to use the values recommended in the datasheet (RT = 2.2kΩ, CT = 3.3nF) and then adjust them based on the specific application requirements.
• What is the purpose of the soft-start pin (SS) and how do I use it?
  The soft-start pin (SS) is used to gradually increase the output voltage during startup, reducing inrush currents and electromagnetic interference (EMI). Connect a capacitor (typically 10nF to 100nF) from the SS pin to ground and a resistor (typically 1kΩ to 10kΩ) from the SS pin to the output voltage.
• How do I ensure the SG3525AN operates in continuous conduction mode (CCM) or discontinuous conduction mode (DCM)?
  The operating mode depends on the inductor value, output current, and switching frequency. For CCM, use a larger inductor value and ensure the inductor current ripple is less than 20% of the output current. For DCM, use a smaller inductor value and ensure the inductor current ripple is greater than 20% of the output current.
• What is the purpose of the undervoltage lockout (UVLO) and how does it work?
  The UVLO prevents the SG3525AN from operating when the input voltage is too low, which could cause unstable operation or damage to the device. The UVLO threshold is typically around 8.5V, and the device will not operate until the input voltage exceeds this threshold.