PCA9545APW 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
PCA9545APW 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
PCA9545APW 9352 758 09118 PCA9545APW,118 量产 PCA9545APW
PCA9545APW 9352 758 09112 PCA9545APW,112 量产 PCA9545APW
订货和供应
型号 订购码 (12NC) 可订购的器件编号 化学成分
PCA9545APW 9352 758 09118 PCA9545APW,118 PCA9545APW
PCA9545APW 9352 758 09112 PCA9545APW,112 PCA9545APW
PCA9545APW 技术支持
档案名称 标题 类型 格式
PCA9545APW 4-channel I2C-bus switch with interrupt logic and reset Data sheet pdf
AN10441 Level shifting techniques in I2C-bus design Application note pdf
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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
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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
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