DS2502P datasheet by Dallas Semiconductor

DS2502P Frequently Asked Questions (FAQs)

• What is the maximum number of devices that can be connected to a single 1-Wire bus?
  Theoretically, up to 256 devices can be connected to a single 1-Wire bus, but in practice, the number is limited by the bus capacitance, wire length, and noise tolerance. A typical limit is around 10-20 devices.
• How do I ensure reliable communication over long 1-Wire bus lengths?
  To ensure reliable communication over long 1-Wire bus lengths, use a strong pull-up resistor (e.g., 1 kΩ), keep the bus capacitance low, and use a repeater or a buffer to amplify the signal.
• What is the purpose of the VPP pin on the DS2502P?
  The VPP (Programming Voltage) pin is used to provide a higher voltage (typically 12V) to the device during EPROM programming. This voltage is required to program the EPROM memory.
• Can I use the DS2502P in a 3.3V system?
  Yes, the DS2502P can operate in a 3.3V system, but the programming voltage (VPP) must still be 12V to program the EPROM memory. The device's core logic operates from 2.2V to 5.5V.
• How do I handle the 1-Wire bus reset signal?
  The 1-Wire bus reset signal is an active low signal that resets all devices on the bus. The master device should generate a reset pulse (typically 480 μs) before starting a new transaction.