NXP | PCA9509GM,125

The PCA9509 is a level translating I2C-bus/SMBus repeater that enables processor low voltage 2-wire serial bus to interface with standard I2C-bus or SMBus I/O. 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) lines, thus enabling the I2C-bus or SMBus maximum capacitance of 400 pF on the higher voltage side. Port A allows a voltage range from 1.0 V (as low as 0.95 V in special cases) to VCC(B) - 1.0 V and requires no external pull-up resistors due to the internal current source. Port B allows a voltage range from 3.0 V to 5.5 V and is overvoltage tolerant. Both port A and port B SDA and SCL pins are high-impedance when the PCA9509 is unpowered.

Features:

• Bidirectional buffer isolates capacitance and allows 400 pF on port B of the device
• Voltage level translation from port A (1 V [0.95 V in special cases] to VCC(B) - 1.0 V) to port B (3.0 V to 5.5 V)
• Requires no external pull-up resistors on lower voltage port A
• Active HIGH repeater enable input
• Open-drain inputs/outputs
• Lock-up free operation
• Supports arbitration and clock stretching across the repeater
• Accommodates Standard-mode and Fast-mode I2C-bus devices and multiple masters
• Powered-off high-impedance I2C-bus pins