VIPER38HE datasheet by STMicroelectronics

VIPER38HE Frequently Asked Questions (FAQs)

• What is the recommended PCB layout for optimal performance of VIPER38HE?
  A good PCB layout for VIPER38HE involves keeping the high-frequency switching nodes (e.g., drain-source voltage) as short as possible, using a solid ground plane, and placing the input and output capacitors close to the IC. A 4-layer PCB with a dedicated power plane and a solid ground plane is recommended.
• How do I ensure reliable start-up of VIPER38HE in my design?
  To ensure reliable start-up, ensure that the input voltage rises slowly (e.g., using a soft-start circuit) and that the input capacitor is large enough to filter out voltage spikes. Also, ensure that the output voltage is properly decoupled and that the feedback network is stable.
• What is the maximum allowed temperature range for VIPER38HE?
  The VIPER38HE is rated for operation from -40°C to 150°C (junction temperature). However, the maximum allowed ambient temperature range depends on the specific application and cooling conditions. Typically, the ambient temperature range is -40°C to 85°C.
• How do I choose the right input and output capacitors for VIPER38HE?
  Choose input capacitors with low ESR (Equivalent Series Resistance) and high ripple current capability. For output capacitors, choose ones with low ESR, high capacitance, and a voltage rating that exceeds the output voltage. The capacitor values and types should be selected based on the specific application requirements and the VIPER38HE's operating conditions.
• What are the key considerations for EMI filtering in VIPER38HE-based designs?
  To minimize EMI, use a common-mode choke and a differential-mode filter at the input, and a shielded inductor or a ferrite bead at the output. Ensure that the PCB layout is optimized for EMI reduction, and that the input and output cables are properly shielded and filtered.