PCA9517A是一款CMOS集成电路,提供低电压(低至0.9 V)和更高电压(2.7 V至5.5 V)I²C总线或SMBus应用之间的电平切换。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,它还允许通过为数据(SDA)和时钟(SCL)线路提供双向缓冲以允许扩展I²C总线,从而可使用两条400 pF的总线。使用PCA9517A能使系统设计师将总线电压和电容隔离成两半。SDA和SCL引脚为耐过压且在PCA9517A未通电时为高阻抗。
2.7 V至5.5 V总线端口B动器的性能类似PCA9515A器件上的驱动器,而可调节电压总线端口A驱动更多电流且消除静态偏移电压。这使端口B的低电平变换成端口A几乎0 V的低电平,适应更低电压逻辑的小电压摆幅。
端口B PCA9517A I/O驱动器的静态偏移设计防止其连接至具有上升时间加速器的另一器件,包括PCA9510、PCA9511、PCA9512、PCA9513、PCA9514、PCA9515A、PCA9516A、PCA9517A(端口B)或PCA9518。但是,可一起连接两个或多个PCA9517A的端口A,以允许端口A在共用总线上的星形拓扑,且端口A可直接连接至带有静态或动态偏移电压的任何其他缓冲器。可按端口A至端口B串联多个PCA9517A,不会积聚偏移电压,只需考虑渡越时间延迟。
除非VCC(A)高于0.8 V且VCC(B)高于2.5 V,否则不会启用PCA9517A驱动器。也可使用EN引脚在系统控制下打开和关闭驱动器。应该注意,当总线闲置时仅改变使能引脚的状态。
端口B内部缓冲器的输出下拉低电平设为大约0.5 V,而内部缓冲器的输入阈值设为大约70 mV以下(0.43 V)。当端口B 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A的输出下拉会驱动一个真正的低电平且输入电平设为0.3VCC(A)以适应系统中更低低电平的需求,其中低电压侧供电电压低至0.9 V。
产品特点 Features
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型号 | 可订购的器件编号 | 订购码 (12NC) | 产品状态 | 封装 |
PCA9517AD | 9352 857 63118 | PCA9517AD,118 | 量产 | SO8 (SOT96-1) |
PCA9517AD | 9352 857 63112 | PCA9517AD,112 | 量产 | SO8 (SOT96-1) |
PCA9517ADP | 9352 857 64118 | PCA9517ADP,118 | 量产 | TSSOP8 (SOT505-1) |
PCA9517ADP/DG | 9352 869 38118 | PCA9517ADP/DG,118 | 量产 | TSSOP8 (SOT505-1) |
型号 | 订购码 (12NC) | 可订购的器件编号 | 化学成分 |
PCA9517AD | 9352 857 63118 | PCA9517AD,118 | PCA9517AD |
PCA9517AD | 9352 857 63112 | PCA9517AD,112 | PCA9517AD |
PCA9517ADP | 9352 857 64118 | PCA9517ADP,118 | PCA9517ADP |
PCA9517ADP/DG | 9352 869 38118 | PCA9517ADP/DG,118 | PCA9517ADP/DG |
档案名称 | 标题 | 类型 | 格式 |
PCA9517A | Level translating I2C-bus 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 PCA9517A I2C-bus extender | Application note | |
75016527 | Extend standard I2C-bus devices without worrying about offset voltages; NXP I2C-bus extender PCA9517A in a proven application | Brochure | |
75016532 | Extend the I2C-bus with advanced repeaters and hubs; NXP 2-channel I2C-bus repeaters PCA9517Ax 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 PCA9517A | 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 |