We take your privacy very seriously, please agree to all cookies used when you visit our website. More information about the processing of personal data could be found inPrivacy Policy



I²C 4-to-1 bidirectional switch

NCA9545 is a four-channel bidirectional switch controlled by I²C bus. SCL/SDA up-link data is spread out to four pairs of down-link data or channels. Any single SCN/SDN channel or combination of channels can be selected, depending on the contents of the programmable control registers. Four interrupt inputs (INT3 to INT0) are provided, each for a down-link pair. One interrupt (INT) output can be used as an AND operation of four interrupt inputs. A low-level on reset (RESET) input enables the NCA9545 to recover from a prolonged low state of any down-link I²C bus. Pulling RESET low resets the I²C state machine and deselects all channels, as does the internal power-on reset function. With a on gate built into the switch, the VCC terminal can be used to limit the maximum voltage delivered by NCA9545. This allows each channel to use a different bus voltage so that parts with voltage of 1.8V, 2.5V or 3.3V can communicate with parts with voltage of  5V without any additional protection. External pull-up resistors pull the bus up to the desired voltage level for each channel. All I/O terminals can withstand 5.5V voltage.

Product Features

• 4-to-1 bidirectional switch 

• Compatible with I²C bus and SMBus

• Low-level on reset input

• 2 address pins, supporting 4 different addresses

• Operation power supply voltage range is 1.65V to 5.5V

• Low standby current

• Supporting hot plugging

• Latch-up performance is higher than 100mA, compliant with JESD78 Class II

• ESD protection performance higher than what are stated in JESD22

o2000V human body charge-discharge model (A114-A)

o1000V charging component model (C101)

• Operation temperature: -40℃~105℃

• RoHS compliant package: TSSOP-20


• Server

• Router (telecom switching equipment)

• Factory automation

• Products with I²C slave address contention

Functional Block Diagram


For more product information, please contact us.


Thank you for your inquiry.

Please provide the following information and we will contact you as soon as possible, thank you.

Consumer Electroncis
Information Communication
Signal Chain
Power Management
I have read and agree to Novosense Private Policy