The PCA9545A/45B/45C is a quad bidirectional translating switch controlled via the I²C‑bus. The SCL/SDA upstream pair fans out to four downstream pairs, or channels. Any individual SCx/SDx channel or combination of channels can be selected, determined by the contents of the programmable control register. Four interrupt inputs, INT0 to INT3, one for each of the downstream pairs, are provided. One interrupt output, INT, acts as an AND of the four interrupt inputs.
An active LOW reset input allows the PCA9545A/45B/45C to recover from a situation where one of the downstream I²C‑buses is stuck in a LOW state. Pulling the RESET pin LOW resets the I²C‑bus state machine and causes all the channels to be deselected as does the internal power‑on reset function.
The pass gates of the switches are constructed such that the VDD pin can be used to limit the maximum high voltage which will be passed by the PCA9545A/45B/45C. This allows the use of different bus voltages on each pair, so that 1.8 V or 2.5 V or 3.3 V parts can communicate with 5 V parts without any additional protection. External pull-up resistors pull the bus up to the desired voltage level for each channel. All I/O pins are 5 V tolerant.
The PCA9545A, PCA9545B and PCA9545C are identical except for the fixed portion of the slave address.
产品特点 Features
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型号 | 可订购的器件编号 | 订购码 (12NC) | 产品状态 | 封装 |
PCA9545APW | 9352 758 09118 | PCA9545APW,118 | 量产 | PCA9545APW |
PCA9545APW | 9352 758 09112 | PCA9545APW,112 | 量产 | PCA9545APW |
型号 | 订购码 (12NC) | 可订购的器件编号 | 化学成分 |
PCA9545APW | 9352 758 09118 | PCA9545APW,118 | PCA9545APW |
PCA9545APW | 9352 758 09112 | PCA9545APW,112 | PCA9545APW |
档案名称 | 标题 | 类型 | 格式 |
PCA9545APW | 4-channel I2C-bus switch with interrupt logic and reset | Data sheet | |
AN10441 | Level shifting techniques in I2C-bus design | Application note | |
AN255 | I2C / SMBus Repeaters, Hubs and Expanders | Application note | |
AN10710 | Features and applications of the PCA9545A_45B_45C I2C-bus extender | Application note | |
75016527 | Extend standard I2C-bus devices without worrying about offset voltages; NXP I2C-bus extender PCA9545A_45B_45C in a proven application | Brochure | |
75016532 | Extend the I2C-bus with advanced repeaters and hubs; NXP 2-channel I2C-bus repeaters PCA9545A_45B_45Cx and 5-channel I2C-bus hubs PCA9516x | Leaflet | |
75016080 | Extend the reach of any I2C-bus system without special offset voltage levels; NXP I2C-bus extender PCA9545A_45B_45C | Leaflet | |
75017424 | NXP I2C-bus solutions 2013: Smart, simple solutions for the 12 most common design concerns | Leaflet | |
UM10204 | I2C-bus specification and user manual | User manual | |
UM10206 | I2C Demonstration Board 2005-1 Quick Start Guide | User manual | |
UM10323 | PCA9600 demonstration board OM6293 | User manual |