SNLS338F January 2011 – November 2014 DS100BR111
PRODUCTION DATA.
The DS100BR111 has an optional internal voltage regulator to provide the 2.5 V supply to the device. In 3.3 V mode, the VIN pin = 3.3 V is used to supply power to the device and the VDD pins should be left open. 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 two VDD pins for power supply de-coupling (total capacitance should be ≤ 0.2 μF). The VDD_SEL pin must be tied to GND to enable the internal regulator. In 2.5 V mode, the VIN pin should be left open and 2.5 V supply must be applied to the VDD pins. The VDD_SEL pin must be left open (no connect) to disable the internal regulator.
The DS100BR111 can be configured for 2.5 V operation or 3.3 V operation. The lists below outline required connections for each supply selection.
NOTE
The DAP (bottom solder pad) is the GND connection.
Two approaches are recommended to ensure that the DS100BR111 is provided with an adequate power supply bypass. First, the supply (VDD) and ground (GND) pins should be connected to power planes routed on adjacent layers of the printed circuit board. Second, careful attention to supply bypassing through the proper use of bypass capacitors is required. A 0.1 μF bypass capacitor should be connected to each VDD pin such that the capacitor is placed as close as possible to the device. Small body size capacitors (such as 0402) reduce the capacitors' parasitic inductance and also help in placement close to the VDD pin. If possible, the layer thickness of the dielectric should be minimized so that the VDD and GND planes create a low inductance supply with distributed capacitance.