SCPU043 March   2021 TCA9416

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Features
  3. 2EVM Setup
    1. 2.1 Load Capacitance Selector
  4. 3Pullup Resistor Selector
    1. 3.1 Board Layout
  5. 4Schematic
    1. 4.1 Bill of Materials

3 Pullup Resistor Selector

The TCA9416EVM provides optional pullup resistor selectors on SDAA, SDAB, SCLA, and SCLB. Remember that the TCA9416 includes its own internal 10-kΩ pullup resistors on the signal lines. The TCA9416EVM also has weak external 20-kΩ pullup resistors populated and denoted as R6, R8, R24, and R25 on the signal lines.

GUID-20210304-CA0I-GTJJ-JWNS-4JQFVXMMVHXQ-low.png Figure 3-1 Pullup Resistor Select

J1, J2, J14, and J15 are used to select the pullup resistors on SCLA, SDAA, SDAB, and SCLB. All jumpers have the letters 'A' and 'B' to denote the value of the pullup resistors. Multiple pullup resistors can be selected on J1, J2, J14, and J15 which would put the pullup resistors in parallel. The possible equivalent pullup resistances are displayed in .Table 3-1.

Table 3-1 J8 and J11 Pullup Resistor Selector
Pullup Resistor Combinations Equivalent Pullup Resistance (Ω)
None Selected 6.6 kΩ
(Internal 10 kΩ plus external 20 kΩ in parallel)
A 4 kΩ

B

 2.7 kΩ
B // C 2.1 kΩ