PCA9646PW中文资料Buffered 4-channel 2-wire bus switch数据手册恩XP规格书

描述 Description

The PCA9646 is a monolithic CMOS integrated circuit for 2-wire bus buffering and switching in applications including I²C-bus, SMBus, PMBus, and other systems based on similar principles.
Each of the four outputs may be independently enabled in any combination as determined by the contents of the programmable control register. Each I/O is impedance isolated from all others, thus allowing a total of five branches of 2-wire bus with the maximum specified load (e.g., 5 × 400 pF for Fm+ I²C-bus at 1 MHz, or 5 × 4 nF at lower frequencies) (Ref. 1). More than one PCA9646 may be used in series, providing a substantial fan-out capability.
The PCA9646 includes a unidirectional buffer for the clock signal, and a bidirectional bufferfor the data signal. The direction of the clock signal may also be set by the contents of theprogrammable control register. Clock stretching and timing must always be under control of themaster device.
The PCA9646 has excellent application to 2-wire bus address expansion and increasing of maximum load capacitance. Very large LED displays are a perfect example.

特性 Features

Drop-in pin compatible with PCA9546A, etc.
Each I/O is impedance isolated from all others allowing maximum capacitance on all branches
30 mA static sink capability on all ports
Works with I²C-bus (Standard-mode, Fast-mode, and Fast-mode Plus (Fm+)), SMBus (standard and high power mode), and PMBus
Fast switching times allow operation in excess of 1 MHz
Allows driving of large loads (e.g., 5 × 4 nF)
Hysteresis on I/O increases noise immunity
Operating voltages from 2.7 V to 5.5 V
Uncomplicated characteristics suitable for quick implementation in most common 2-wire bus applications
ESD protection exceeds 2000 V HBM per JESD22-A114 and 1000 V CDM perJESD22-C101
Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA

应用 Application

Large arrays of I²C-bus components, e.g., LED displays
Power management systems
Game consoles, computers, RAID systems