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TCA9803

SCPS267B – MARCH 2017 – REVISED FEBRUARY 2020

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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 Application Information

10.1.1 Device Selection Guide

The TCA980x family has 4 different variants, with different strengths of the internal current source as shown in

Table 5.

Table 5. TCA980x Family

Part Number

ICS: Current Source Value

TCA9800

0.54 mA

TCA9801

1.1 mA

TCA9802

2.2 mA

TCA9803

3.3 mA

It is acceptable to select the TCA9803 as the default, since it is able to drive 400-pF bus capacitance loads at

400 kHz. For system designers looking to optimize selection, see the Detailed Design Procedure section for

single device for detailed examples of how to select a part number for a specific application.

10.1.2 Special Considerations for the B-side

The TCA980x supports many types of connections between other TCA980x and other buffers/translators. Care

must be taken to ensure that all of the B-side requirements be satisfied. For example, FET/pass-gate based

translators typically cannot be used on the B-side, because they require pull-up resistors on both sides, and

when one side is pulling low, the FET/switch closes, likely causing IEXT-I to be violated (See the IEXT-I section for

more information).

The FET or Pass-Gate Translators and Buffered Translators/Level-shifters sections list some use-cases that are

not supported or require special considerations when connected to the B-ports, note that these considerations

only apply to the B-side of the TCA980x family.

10.1.2.1 FET or Pass-Gate Translators

Some translators are based on pass-gates for translation support. In most of the use cases, external pull-up

resistors are required to pull the bus to the voltage rail.