10.1 3.3-V or 2.5-V Supply Mode Operation

The DS125BR800 has an optional internal voltage regulator to provide the 2.5-V supply to the device. In 3.3-V mode operation, the VIN pin = 3.3 V is used to supply power to the device. The internal regulator will provide the 2.5 V to the VDD pins of the device and a 0.1-µF cap is needed at each of the 5 VDD pins for power supply de-coupling (total capacitance should be ≤0.5 µF), and the VDD pins should be left open. The VDD_SEL pin must be tied to GND to enable the internal regulator. In 2.5-V mode operation, the VIN pin should be left open and 2.5-V supply must be applied to the 5 VDD pins to power the device. The VDD_SEL pin must be left open (no connect) to disable the internal regulator.

The DS125BR800 has an optional internal voltage regulator to provide the 2.5 V supply to the device. In 3.3-V Mode operation, the VIN pin = 3.3 V is used to supply power to the device. The internal regulator will provide the 2.5 V to the VDD pins of the device and a 0.1-µF cap is needed at each of the 5 VDD pins for power supply decoupling (total capacitance should be ≤0.5 µF), and the VDD pins should be left open. The VDD_SEL pin must be tied to GND to enable the internal regulator. In 2.5-V Mode operation, the VIN pin should be left open and 2.5-V supply must be applied to the 5 VDD pins to power the device. The VDD_SEL pin must be left open (no connect) to disable the internal regulator.

Figure 26. 3.3-V or 2.5-V Supply Connection Diagram