PCA9525 Simple 2-wire bus buffer Rev. 1 25 February 2011 Product data sheet 1. General description The PCA9525 is a monolithic CMOS integrated circuit for bus buffering in applications 2 including I C-bus, SMBus, DDC, PMBus, and other systems based on similar principles. The buffer extends the bus load limit by buffering both the SCL and SDA lines, allowing the maximum permissible bus capacitance on both sides of the buffer. The PCA9525 includes a unidirectional buffer for the clock signal, and a bidirectional buffer for the data signal. Slave devices which employ clock stretching are therefore not supported. In its most basic implementation, the buffer will allow an extended number of slave devices to be attached to one (or more) master devices. In this case, all master devices would be positioned on the Sxx IN side of the PCA9525. The direction pin (DIR) further enhances this function by allowing the unidirectional clock signal to be reversed, thus allowing master devices on both sides of the buffer. The enable (EN) function allows sections of the bus to be isolated. Individual parts of the system can be brought on-line successively. This means a controlled start-up using a diverse range of components, operating speeds and loads is easily achieved. 2. Features and benefits Simple impedance isolating buffer for 2-wire buses 4 mA maximum static open-drain pull-down capability supports a wide range of bus standards 2 Works with I C-bus (Standard-mode, Fast-mode), SMBus (standard and high power mode), and PMBus Fast switching times allow operation in excess of 1 MHz Enable allows bus segments to be disconnected Hysteresis on inputs provides noise immunity Operating voltages from 2.7 V to 5.5 V Very low supply current Uncomplicated characteristics suitable for quick implementation in most common 2-wire bus applicationsPCA9525 NXP Semiconductors Simple 2-wire bus buffer 3. Applications Electronic signs and displays Game consoles/boxes Gaming machine networks TV/projector/monitor interconnection (DDC) Power management systems Desktop and portable computers Security systems 4. Ordering information Table 1. Ordering information Type number Topside Package mark Name Description Version PCA9525D PCA9525 SO8 plastic small outline package 8 leads body width 3.9 mm SOT96-1 PCA9525DP 9525 TSSOP8 plastic thin shrink small outline package 8 leads body width 3 mm SOT505-1 5. Block diagram 2.7 V to 5.5 V V DD R1 R2 R3 R4 8 PCA9525 EN 1 enable SDA IN 6 7 SDA OUT SDA SDA SCL IN 3 2 SCL OUT SCL SCL DIR 5 direction 4 V SS 002aaf329 Fig 1. Block diagram of PCA9525 PCA9525 All information provided in this document is subject to legal disclaimers. NXP B.V. 2011. All rights reserved. Product data sheet Rev. 1 25 February 2011 2 of 22