ISOUSB211DPR datasheet(25/44 Pages) TI

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10 Application and Implementation

Note

Information in the following applications sections is not part of the TI component specification, and

TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining

suitability of components for their purposes. Customers should validate and test their design

implementation to confirm system functionality.

10.1 Typical Application

10.1.1 Isolated Host or Hub

Figure 10-1 shows an application for isolating a host or a hub using ISOUSB211. In this example, on the

microntroller side, V3P3V1 and VBUS1 are together connected to an external 3.3-V supply. The V1P8V1 supply is

generated using the internal 1.8-V LDO by providing 3.3-V supply to VCC1. On the connector side, the VBUS

from the USB connector is connected to VBUS2 and the V3P3V2 supply is generated using the internal 3.3-V

LDO. VCC2 and V1P8V2 are together connected to an external 1.8-V supply derived from VBUS. Please refer to

Thermal Considerations for options on optimizing power dissipation inside ISOUSB211 as required.

Decoupling capacitors are placed next to ISOUSB211 according to the recommendations provided in the Power

Supply Recommendations section. An isolated DC-DC converter (such as the SN6505) is to provide power

to the VBUS using the 3.3-V local supply. Note that, for a host or hub, the USB standard requires a 120-μF

capacitor to be placed on the VBUS so as to be able provide in-rush current when a downstream peripheral is

attached. In addition, a 100-nF capacitor is recommended close to the VBUS pin to handle tranisent currents.

ESD diodes with low capacitance and low dynamic resistance, such as PESD5V0C1USF, may be placed on D+

and D- lines. A ferrite bead, with dc resistance less than 100 mΩ, may be optionally placed between VBUS pin of

the connector and the VBUS pin of ISOUSB211, as shown in the figure, to suppress transients such as ESD.

If the isolated power supply used is capable of providing >1.5 A current on the VBUS, the port can be configured

as a CDP port according to Battery Charger specification BC 1.2. To do this, the CDPENZ2 pin of ISOUSB211

must be connected to ground as shown. Under this condition ISOUSB211 responds to BC 1.2 signaling from a

connected peripheral indicating to the peripheral that the port is capable of supply 1.5-A current on VBUS.

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ISOUSB211

SLLSFC5B – NOVEMBER 2021 – REVISED SEPTEMBER 2022

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ISOUSB211DPR Datasheet(PDF) 25 Page - Texas Instruments