LM139AD datasheet by Texas Instruments

LM139AD Frequently Asked Questions (FAQs)

• What is the maximum voltage that can be applied to the input pins?
  The maximum voltage that can be applied to the input pins is the supply voltage (VCC) + 0.3V. Exceeding this voltage can cause damage to the device.
• How do I ensure that the comparator output is not oscillating?
  To prevent oscillation, ensure that the input signals are properly filtered and that the comparator is properly biased. Additionally, adding a small capacitor (e.g. 10nF) between the output and ground can help to reduce oscillations.
• What is the minimum input voltage required for the comparator to function correctly?
  The minimum input voltage required for the comparator to function correctly is typically around 1.5V to 2V above the negative supply voltage (VSS). However, this can vary depending on the specific application and operating conditions.
• Can I use the LM139AD as a voltage regulator?
  No, the LM139AD is a comparator, not a voltage regulator. It is designed to compare two input voltages and output a digital signal indicating which input is higher. It is not designed to regulate voltage.
• How do I choose the correct pull-up resistor value for the output?
  The pull-up resistor value depends on the specific application and the load connected to the output. A general rule of thumb is to choose a value between 1kΩ to 10kΩ. However, it's recommended to consult the datasheet and application notes for more specific guidance.