ZHCSC52D January 2014 – November 2019 TCA9545A
PRODUCTION DATA.
- 1 特性
- 2 應(yīng)用
- 3 說(shuō)明
- 4 修訂歷史記錄
- 5 Pin Configuration and Functions
- 6 Specifications
- 7 Parameter Measurement Information
- 8 Detailed Description
- 9 Application and Implementation
- 10Power Supply Recommendations
- 11Layout
- 12器件和文檔支持
- 13機(jī)械、封裝和可訂購(gòu)信息
封裝選項(xiàng)
機(jī)械數(shù)據(jù) (封裝 | 引腳)
- PW|20
散熱焊盤機(jī)械數(shù)據(jù) (封裝 | 引腳)
訂購(gòu)信息
9.2.2 Detailed Design Procedure
Once all the slaves are assigned to the appropriate slave channels and bus voltages are identified, the pull-up resistors, Rp, for each of the buses need to be selected appropriately. The minimum pull-up resistance is a function of VDPUX, VOL,(max), and IOL:
The maximum pull-up resistance is a function of the maximum rise time, tr (300 ns for fast-mode operation, fSCL = 400 kHz) and bus capacitance, Cb:
The maximum bus capacitance for an I2C bus must not exceed 400 pF for fast-mode operation. The bus capacitance can be approximated by adding the capacitance of the TCA9545A, Cio(OFF), the capacitance of wires/connections/traces, and the capacitance of each individual slave on a given channel. If multiple channels will be activated simultaneously, each of the slaves on all channels will contribute to total bus capacitance.