ISP1105W datasheet by Philips Semiconductors

ISP1105W Frequently Asked Questions (FAQs)

• What is the recommended PCB layout for optimal performance?
  A 4-layer PCB with a solid ground plane and a separate power plane is recommended. Keep the analog and digital signal traces separate and avoid crossing them. Use a 50-ohm impedance-controlled trace for the USB differential pairs.
• How do I ensure reliable USB connectivity and avoid signal integrity issues?
  Use a high-quality USB connector, ensure proper termination of the USB differential pairs, and add a common-mode filter (e.g., a ferrite bead) to reduce EMI. Also, follow the recommended PCB layout and routing guidelines.
• What is the maximum cable length supported by the ISP1105W?
  The ISP1105W supports cable lengths up to 3 meters (10 feet) for USB 2.0 and 1.5 meters (5 feet) for USB 1.1. However, the actual cable length may vary depending on the specific application and cable quality.
• How do I configure the ISP1105W for low-power operation?
  To minimize power consumption, set the device to the suspend mode (SUSPEND pin low) when not in use. You can also reduce the clock frequency and adjust the voltage regulator settings to optimize power consumption.
• What are the thermal management considerations for the ISP1105W?
  The ISP1105W has a thermal pad on the bottom of the package. Ensure good thermal conductivity by using a thermal pad or thermal tape on the PCB. Keep the device away from heat sources and ensure good airflow around the component.