LM3900N datasheet by Texas Instruments

LM3900N Frequently Asked Questions (FAQs)

• What is the maximum input voltage that can be applied to the LM3900N?
  The maximum input voltage that can be applied to the LM3900N is 40V, but it's recommended to keep it below 35V for reliable operation.
• How do I ensure the LM3900N is stable and doesn't oscillate?
  To ensure stability, make sure to decouple the input and output with capacitors, use a minimum of 10uF capacitor at the output, and keep the layout clean and compact to minimize parasitic inductance and capacitance.
• What is the minimum input voltage required for the LM3900N to regulate the output?
  The minimum input voltage required for the LM3900N to regulate the output is around 7.5V, but it's recommended to keep it above 8V for reliable operation.
• Can I use the LM3900N as a negative voltage regulator?
  No, the LM3900N is designed to regulate positive voltages only. If you need a negative voltage regulator, consider using a different IC like the LM7900 or LM7910.
• How do I calculate the output voltage of the LM3900N?
  The output voltage of the LM3900N can be calculated using the formula: Vout = (R1 / R2) * 1.25V, where R1 and R2 are the resistors used in the voltage divider circuit.