PCA9646 Buffered 4-channel 2-wire bus switch Rev. 2 17 June 2015 Product data sheet 1. General description The PCA9646 is a monolithic CMOS integrated circuit for 2-wire bus buffering and 2 switching in applications including I C-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 2 load (e.g., 5 400 pF for Fm+ I C-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 buffer for the data signal. The direction of the clock signal may also be set by the contents of the programmable control register. Clock stretching and timing must always be under control of the master 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. 2. Features and benefits 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 2 Works with I C-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 4nF) 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 per JESD22-C101 Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mAPCA9646 NXP Semiconductors Buffered 4-channel 2-wire bus switch 3. Applications 2 Large arrays of I C-bus components, e.g., LED displays Power management systems Game consoles, computers, RAID systems 4. Ordering information Table 1. Ordering information Type number Topside Package marking Name Description Version PCA9646PW PCA9646 TSSOP16 plastic thin shrink small outline package 16 leads SOT403-1 body width 4.4 mm 4.1 Ordering options Table 2. Ordering options Type number Orderable Package Packing method Minimum Temperature part number order quantity PCA9646PW PCA9646PW,118 TSSOP16 REEL 13 Q1/T1 2500 T = 40 C to +85 C amb *STANDARD MARK SMD PCA9646 All information provided in this document is subject to legal disclaimers. NXP Semiconductors N.V. 2015. All rights reserved. Product data sheet Rev. 2 17 June 2015 2 of 22