PCA9509P是一款电平变换I²C总线/SMBus转发器,带有能使处理器低电压2线串行总线连接标准I²C总线或SMBus I/O的两个电压源。在电平切换过程中保留I²C总线系统所有工作模式和功能的同时,还允许通过为数据(SDA)和时钟(SCL)线路提供双向缓冲来扩展I²C总线,从而使I²C总线或SMBus在高电压侧能有最大400 pF的电容。端口A允许电压范围为0.8 V至1.5 V且耐过压。端口B允许2.3 V至5.5 V的电压范围且耐过压。端口A和端口B的SDA和SCL引脚在PCA9509P未通电时均为高阻抗。
总线端口B驱动器兼容SMBus I/O电平,而端口A使用偏移LOW防止总线锁定并允许器件具有双向性质。端口A内部缓冲器低电平上的输出下拉设为大约0.2 VCC(A),而内部缓冲器的输入阈值设为比低电平输出电压的低大约0.1 VCC(A)。当端口A I/O内部驱动为低电平时,输入端不会将低电平识别为低电平。这能防止发生锁定状况。端口B上的输出下拉驱动真正的LOW且输入电平设为大约SMBus或I²C总线电压电平的0.3,能使端口B连接至任何其他I²C总线器件或缓冲器。
除非VCC(A)高于0.7 V且VCC(B)高于1.7 V,否则不会启用PCA9509P驱动器。也可使用使能(EN)引脚在系统控制下打开和关闭驱动器。应该注意,当总线闲置时才能改变EN引脚的状态。
PCA9509P与PCA9509A相同,但没有端口A内部电流源,可使用高值上拉电阻来减少便携式应用的电流消耗。
产品特点 Features
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产品实物图 |
型号 | 可订购的器件编号 | 订购码 (12NC) | 产品状态 | 封装 |
PCA9509PDP | 9352 979 55118 | PCA9509PDP,118 | 量产 | TSSOP8 (SOT505-1) |
型号 | 订购码 (12NC) | 可订购的器件编号 | 化学成分 |
PCA9509PDP | 9352 979 55118 | PCA9509PDP,118 | PCA9509PDP |
档案名称 | 标题 | 类型 | 格式 |
PCA9509PDP | Low power level translating I2C-bus/SMBus repeater | Data sheet | |
AN10441 | Level shifting techniques in I2C-bus design | Application note | |
AN255 | I2C / SMBus Repeaters, Hubs and Expanders | Application note | |
AN10710 | Features and applications of the PCA9509P I2C-bus extender | Application note | |
75016527 | Extend standard I2C-bus devices without worrying about offset voltages; NXP I2C-bus extender PCA9509P in a proven application | Brochure | |
75016532 | Extend the I2C-bus with advanced repeaters and hubs; NXP 2-channel I2C-bus repeaters PCA9515x and 5-channel I2C-bus hubs PCA9516x | Leaflet | |
75016080 | Extend the reach of any I2C-bus system without special offset voltage levels; NXP I2C-bus extender PCA9509P | Leaflet | |
75017424 | NXP I2C-bus solutions 2013: Smart, simple solutions for the 12 most common design concerns | Leaflet | |
UM10204 | I2C-bus specification and user manual | User manual | |
UM10206 | I2C Demonstration Board 2005-1 Quick Start Guide | User manual | |
UM10323 | PCA9600 demonstration board OM6293 | User manual |