NXP PCA9507DP

Overview

The PCA9507DP is a 2-wire serial bus extender providing 3.3 V to 5 V level shift that allows up to 18 meters bus extension for reliable DDC, I²C-bus or SMBus applications. While retaining all the operating modes and features of the I²C-bus system during the level shifts, it also permits extension of the I²C-bus by providing bidirectional buffering for both the data (SDA) and the clock (SCL) line as well as the rise time accelerator on port A enabling the bus to drive a load up to 1400 pF or distance of 18 m on port A, and 400 pF on port B. Using the PCA9507DP enables the system designer to isolate bus capacitance to meet HDMI DDC version 1.3 distance specification. The SDA and SCL pins are overvoltage tolerant and are high-impedance when the PCA9507DP is unpowered.

The PCA9507DP drivers are not enabled unless VCC(A) and VCC(B) are above 2.7 V. The EN pin can also be used to turn the drivers on and off under system control. Caution should be observed to only change the state of the enable pin when the bus is idle. The output pull-down on the port B internal buffer LOW is set for approximately 0.5 V, while the input threshold of the internal buffer is set about 70 mV lower (0.43 V). When the port B I/O is driven LOW internally, the LOW is not recognized as a LOW by the input. This prevents a lock-up condition from occurring.

Features