ZHCSQB9H April 2006 – March 2022 PCA9536
PRODUCTION DATA
- 1 特性
- 2 應用
- 3 說明
- 4 Revision History
- 5 Pin Configuration and Functions
- 6 Specifications
- 7 Parameter Measurement Information
- 8 Detailed Description
- 9 Application Information Disclaimer
- 10Power Supply Recommendations
- 11Layout
- 12Device and Documentation Support
- 13Mechanical, Packaging, and Orderable Information
9.2.2 Detailed Design Procedure
The pull-up resistors, RP, for the SCL and SDA lines need to be selected appropriately and take into consideration the total capacitance of all targets on the I2C bus. The minimum pull-up resistance is a function of VCC, VOL,(max), and IOL as shown in Equation 1:
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 as shown in Equation 2:
The maximum bus capacitance for an I2C bus must not exceed 400 pF for standard-mode or fast-mode operation. The bus capacitance can be approximated by adding the capacitance of the PCA9536, Ci for SCL or Cio for SDA, the capacitance of wires,connections or traces, and the capacitance of additional targets on the bus.