T1235H-8I - STMicroelectronics

T1235H-8I Frequently Asked Questions (FAQs)

• What is the recommended PCB layout for optimal thermal performance?
  STMicroelectronics provides a recommended PCB layout in their application note AN5046, which includes guidelines for thermal pad connection, copper pouring, and via placement to ensure optimal thermal performance.
• How do I handle the thermal shutdown feature?
  The thermal shutdown feature is enabled by default. To handle it, monitor the TSD (Thermal Shutdown) pin, which goes low when the junction temperature exceeds 170°C. When TSD is low, the device is in thermal shutdown mode, and the output voltage is disabled. Wait for the device to cool down before re-enabling the output voltage.
• What is the maximum allowed voltage on the VIN pin?
  Although the datasheet specifies a maximum input voltage of 18V, it's recommended to limit the input voltage to 15V to ensure reliable operation and prevent damage to the internal components.
• How do I calculate the output voltage ripple?
  The output voltage ripple can be calculated using the formula: ΔVout = (Iout * ESL) / (Cout * fsw), where ESL is the equivalent series inductance of the output capacitor, Cout is the output capacitance, and fsw is the switching frequency. A lower ESL and higher Cout value can help reduce the output voltage ripple.
• What is the recommended input capacitor type and value?
  STMicroelectronics recommends using a low-ESR ceramic capacitor (e.g., X7R or X5R) with a value of 10uF to 22uF, depending on the input voltage and current requirements. This helps to filter out high-frequency noise and ensure stable operation.