PCA9549

PCA9549 Octal bus switch with individually I2C-bus controlled enables Rev. 02 — 13 July 2009 Product data sheet 1. General description The PCA9549 provides eight bits of high speed TTL-compatible bus switching controlled by the I2C-bus. The low ON-state resistance of the switch allows connections to be made with minimal propagation delay. Any individual A to B channel or combination of channels can be selected via the I2C-bus, determined by the contents of the programmable Control register. When the I2C-bus bit is HIGH (logic 1), the switch is on and data can flow from Port A to Port B, or vice versa. When the I2C-bus bit is LOW (logic 0), the switch is open, creating a high-impedance state between the two ports, which stops the data flow. An active LOW reset input (RESET) allows the PCA9549 to recover from a situation where the I2C-bus is stuck in a LOW state. Pulling the RESET pin LOW resets the I2C-bus state machine and causes all the bits to be open, as does the internal power-on reset function. Three address pins allow up to eight devices on the same bus. 2. Features I 8-bit bus switch (CBT) I 5 Ω switch connection between two ports I I2C-bus interface logic; compatible with SMBus standards I Active LOW RESET input I 3 address pins allowing up to 8 devices on the I2C-bus I Bit selection via I2C-bus, in any combination I Power-up with all bits deselected I Low Ron switches I No glitch on power-up I Supports hot insertion I Low standby current I Operating power supply vo...