PCA9545AD 4-channel I²C-bus switch with interrupt logic and reset

The PCA9545A/45B/45C is a quad bidirectional translating switch controlled via the I²C‑bus. The SCL/SDA upstream pair fans out to four 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. Four interrupt inputs, INT0 to INT3, one for each of the downstream pairs, are provided. One interrupt output, INT, acts as an AND of the four interrupt inputs.

An active LOW reset input allows the PCA9545A/45B/45C to recover from a situation 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 causes all the channels to be deselected as does the internal power‑on reset function.

The pass gates of the switches are constructed such that the VDD pin can be used to limit the maximum high voltage which will be passed by the PCA9545A/45B/45C. 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.

The PCA9545A, PCA9545B and PCA9545C are identical except for the fixed portion of the slave address.

产品特点 Features

1-of-4 bidirectional translating switches
I²C-bus interface logic; compatible with SMBus standards
4 active LOW interrupt inputs
Active LOW interrupt output
Active LOW reset input
2 address pins allowing up to 4 devices on the I²C-bus
Alternate address versions A, B and C allow up to a total of 12 devices on the bus for larger systems or to resolve address conflicts
Channel selection via I²C-bus, in any combination
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 Hz to 400 kHz clock frequency
ESD protection exceeds 2000 V HBM per JESD22‑A114 and 1000 V CDM per JESD22‑C101
Latch-up protection exceeds 100 mA per JESD78
Three packages offered: SO20, TSSOP20, and HVQFN20

功能框图

封装

型号	可订购的器件编号	订购码 (12NC)	产品状态	封装
PCA9545AD	9352 758 08118	PCA9545AD,118	量产	SO20 (SOT163-1)
PCA9545AD	9352 758 08112	PCA9545AD,112	量产	SO20 (SOT163-1)

订货和供应

型号	订购码 (12NC)	可订购的器件编号	化学成分
PCA9545AD	9352 758 08118	PCA9545AD,118	PCA9545AD
PCA9545AD	9352 758 08112	PCA9545AD,112	PCA9545AD

PCA9545AD 技术支持

档案名称	标题	类型	格式
PCA9545AD	4-channel I2C-bus switch with interrupt logic and reset	Data sheet	pdf
AN10441	Level shifting techniques in I2C-bus design	Application note	pdf
AN255	I2C / SMBus Repeaters, Hubs and Expanders	Application note	pdf
AN10710	Features and applications of the PCA9545A_45B_45C I2C-bus extender	Application note	pdf
75016527	Extend standard I2C-bus devices without worrying about offset voltages; NXP I2C-bus extender PCA9545A_45B_45C in a proven application	Brochure	pdf
75016532	Extend the I2C-bus with advanced repeaters and hubs; NXP 2-channel I2C-bus repeaters PCA9545A_45B_45Cx and 5-channel I2C-bus hubs PCA9516x	Leaflet	pdf
75016080	Extend the reach of any I2C-bus system without special offset voltage levels; NXP I2C-bus extender PCA9545A_45B_45C	Leaflet	pdf
75017424	NXP I2C-bus solutions 2013: Smart, simple solutions for the 12 most common design concerns	Leaflet	pdf
UM10204	I2C-bus specification and user manual	User manual	pdf
UM10206	I2C Demonstration Board 2005-1 Quick Start Guide	User manual	pdf
UM10323	PCA9600 demonstration board OM6293	User manual	pdf