PCA9548APWR

The PCA9548A has eight bidirectional translating switches that can be controlled via the I²C bus. The SCL/SDA upstream pair fans out to eight 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. The system master can reset the PCA9548A in the event of a timeout or other improper operation by asserting a low in the RESET input. Similarly, the power-on reset deselects all channels and initializes the I2C/SMBus state machine. Asserting RESET causes the same reset/initialization to occur without powering down the part. The pass gates of the switches are constructed so that the VCC pin can be used to limit the maximum high voltage, which is passed by the PCA9548A. 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.

Applications

• Servers
• Routers (Telecom Switching Equipment)
• Factory Automation Products With I²C Slave Address Conflicts (e.g. Multiple, Identical Temp Sensors)

Key features

• 1-of-8 Bidirectional Translating Switches
• I²C Bus and SMBus Compatible
• Active-Low Reset Input
• Three Hardware Address Pins for Use of up to Eight PCA9548A Devices on the I²C Bus
• Channel Selection Via I²C Bus
• Power-Up with All Switch Channels Deselected
• Low R_ON Switches Allows Voltage-Level Translation Between 1.8-V, 2.5-V, 3.3-V, and 5-V Buses
• No Glitch on Power Up
• Supports Hot Insertion
• Low Standby Current
• Operating Power-Supply Voltage Range of 2.3 V to 5.5 V
• 5-V Tolerant Inputs
• 0 to 400-kHz Clock Frequency
• Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
• ESD Protection Exceeds JESD 22
• 2000-V Human-Body Model (A114-A)
• 200-V Machine Model (A115-A)
• 1000-V Charged-Device Model (C101)