Nexperia NCA9548A 8-Channel I²C Bus Switches
Nexperia NCA9548A 8-Channel I2C Bus Switches are octal bidirectional translating switches controlled through the I2C bus. The SCL/SDA upstream pair spreads to eight downstream pairs, or channels. The contents of the programmable control register decide whether an individual SCn/SDn channel or a mixture of channels can be selected.
An active LOW reset input enables the Nexperia NCA9548A to recover from a circumstance 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 drives all the channels to be deselected, as does the internal power-on reset function.
The switch pass gates implement the VCC pin, which can be utilized to limit the maximum high voltage that the NCA9548A will pass. This feature permits the use of different bus voltages on each pair, so that 1.8V, 2.5V, or 3.3V parts can communicate with 5V parts without additional protection.
The external pull-up resistors increase the desired voltage level for each channel. The I/O pins are 6V tolerant.
Features
- 1-of-8 bidirectional translating switches
- I2C bus interface logic; compatible with SMBus standards
- Active LOW reset input
- Three address pins allow up to eight devices on the I2C bus
- Channel selection via the I2C bus, in any combination
- Power up with all switch channels deselected
- Low Ron switches
- Allows voltage level translation between 1.8V, 2.5V, 3.3V, and 5V buses
- No glitch on power-up
- Supports hot insertion
- Low standby current
- Operating power supply voltage range of 1.65V to 5.5V
- 6V-tolerant inputs
- 0Hz to 400kHz clock frequency
- Latch-up testing is done to JEDEC Standard JESD78, which exceeds 100mA
- Two packages offered are TSSOP24 and HWQFN24
- ESD protection:
- HBM: ANSI/ESDA/JEDEC JS-001 class 2 exceeds 2kV
- CDM: ANSI/ESDA/JEDEC JS-002 class C3 exceeds 1kV
- Specified from -40°C to +85°C and from -40°C to +125°C
Applications
- Battery-powered devices
- Sensors
- Keypads
- Push buttons
- LED control for managing LED brightness
Associated Multiplexers
Nexperia NCA9547A 8-Channel I²C Bus Multiplexers
Octal bidirectional translating devices managed by the I2C bus.
Nexperia NCA6416 Low-Voltage 16-Bit I/O Expanders
Developed for microcontrollers that require additional I/O pins.
Simplified Application
Block diagram
