深圳市谷科智电子有限公司

描述

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.

特性1-of-8 Bidirectional Translating SwitchesI2C Bus and SMBus CompatibleActive-Low Reset InputThree Hardware Address Pins for Use of up to

Eight PCA9548A Devices on the I2C BusChannel Selection Via I2C BusPower-Up with All Switch Channels DeselectedLow RON SwitchesAllows Voltage-Level Translation Between 1.8-V,

2.5-V, 3.3-V, and 5-V BusesNo Glitch on Power UpSupports Hot InsertionLow Standby CurrentOperating Power-Supply Voltage Range of 2.3 V to 5.5 V5-V Tolerant Inputs0 to 400-kHz Clock FrequencyLatch-Up Performance Exceeds 100 mA Per JESD 78, Class IIESD Protection Exceeds JESD 222000-V Human-Body Model (A114-A)200-V Machine Model (A115-A)1000-V Charged-Device Model (C101)