LTC7890RUJM#PBF - Analog Devices

LTC7890RUJM#PBF Frequently Asked Questions (FAQs)

• What is the maximum input voltage that can be applied to the LTC7890?
  The maximum input voltage that can be applied to the LTC7890 is 60V, but it's recommended to limit it to 50V for reliable operation.
• How do I ensure the LTC7890 is in a stable operating condition during startup?
  To ensure stable operation during startup, make sure the input voltage is ramped up slowly (typically 10ms to 100ms) and the EN pin is pulled high after the input voltage has reached the minimum operating voltage (around 6.5V).
• What is the recommended layout and placement for the LTC7890?
  For optimal performance, place the LTC7890 close to the input capacitors and keep the high-current paths short. Use a solid ground plane and avoid routing high-frequency signals near sensitive analog nodes.
• How do I calculate the output voltage ripple of the LTC7890?
  The output voltage ripple of the LTC7890 can be estimated 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.
• What is the thermal derating of the LTC7890 and how do I calculate it?
  The thermal derating of the LTC7890 is typically 1.5°C/W above 25°C. To calculate the maximum power dissipation, use the formula: Pd(max) = (Tj(max) - Ta) / θja, where Tj(max) is the maximum junction temperature (150°C), Ta is the ambient temperature, and θja is the junction-to-ambient thermal resistance (45°C/W).