PCA9548A

具有复位功能的 8 通道 I2C 开关

The 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.

.

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 RON 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