MAX3485CPA+ datasheet by Maxim Integrated Products

MAX3485CPA+ Frequently Asked Questions (FAQs)

• What is the recommended layout and routing for the MAX3485CPA+ to minimize EMI and ensure reliable operation?
  The MAX3485CPA+ requires careful PCB layout and routing to minimize EMI and ensure reliable operation. Maxim Integrated provides a recommended layout and routing guide in their application note AN1896, which includes guidelines for component placement, trace routing, and grounding.
• How do I ensure the MAX3485CPA+ is properly terminated for RS-485 applications?
  Proper termination is critical for RS-485 applications. The MAX3485CPA+ requires a termination resistor (RTERM) between the Y and Z outputs to match the characteristic impedance of the cable. The recommended termination resistor value is 120 ohms for a 120-ohm cable.
• What is the maximum cable length supported by the MAX3485CPA+?
  The MAX3485CPA+ supports cable lengths up to 4000 feet (1219 meters) at a data rate of 10 Mbps. However, the actual cable length supported depends on the specific application, cable quality, and data rate.
• How do I handle hot swapping or insertion/removal of cables with the MAX3485CPA+?
  The MAX3485CPA+ is designed to handle hot swapping or insertion/removal of cables. However, it's essential to ensure that the cable is properly terminated and the transmitter is disabled during hot swapping to prevent damage to the device.
• What are the thermal considerations for the MAX3485CPA+?
  The MAX3485CPA+ has a maximum junction temperature (TJ) of 150°C. To ensure reliable operation, it's essential to provide adequate heat sinking and thermal management to keep the device within its recommended operating temperature range.