SLLSFW6 March 2024 ISOUSB211-Q1
ADVANCE INFORMATION
0.1 µF capacitors are recommended to be placed very close to V3P3Vx pins to GNDx. 1-µF capacitors are recommended to be placed placed very close to VBUSx pins to GNDx. 2-µF, 0.1-µF, and 10-nF capacitors are recommended to be placed between V1P8Vx and GNDx, between pins 4 and 3, between pins 25 and 26, between pins 11 and 12, and between pins 25 and 26 respectively, as close to the device as possible. Place the lower value capacitors closer to the IC. If VCCx pins are connected through resistors as shown in Example Configuration 3 1-µF capacitors are recommended to be placed between VCCx (pins 5, 24) and GNDx (pins 3, 26), as close to the device as possible, with higher priority being accorded to the capacitors on V1P8Vx pins.
These decoupling capacitor recommendations are irrespective of whether the 3.3 V and 1.8 V supplies are provided externally or generated using internal LDOs.
Refer to the Section 8.5.1.1 section for recommended placement of the decoupling capacitors. Small footprint capacitors (0402/0201) are recommended so that these may be placed very close to the supply pins and corresponding ground pins on the top layer without the use of vias. The capacitors on V1P8Vx supplies are higher in priority when considering placement close to the IC.
While isolating a host/hub or bus-powered peripherals, isolated power is needed and can be generated with the help of a transformer driver such as TI's SN6505B. For such applications, detailed power supply design, and transformer selection recommendations are available in the SN6505 Low-Noise 1-A Transformer Drivers for Isolated Power Supplies data sheet. If CDP functionality is enabled while isolation host/hub, the isolated power supply must be capable of delivering 1.5 A on VBUS.