PCA9509GM,125

Signal Buffers, Repeaters, Splitters Overview

The PCA9509GM,125 is a level translating I2C-bus/SMBus repeater manufactured by NXP Semiconductors. It enables processor low voltage 2-wire serial bus to interface with standard I2C-bus or SMBus I/O while retaining all operating modes during level shifts. The device provides bidirectional buffering for data (SDA) and clock (SCL) lines, allowing extension of the I2C-bus with a maximum capacitance of 400 pF on the higher voltage side. Port A operates from 1.35 V to VCC(B) - 1.0 V without external pull-ups, while Port B operates from 3.0 V to 5.5 V and is overvoltage tolerant. It supports Standard-mode and Fast-mode I2C devices up to 400 kHz.

Signal Buffers, Repeaters, Splitters Feature Summary

• Bidirectional buffer isolates capacitance and allows 400 pF on port B
• Voltage level translation from port A (1.35 V 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
• Operating supply voltage range of 1.35 V to VCC(B) - 1.0 V on port A, 3.0 V to 5.5 V on port B
• 5 V tolerant port B SCL, SDA and enable pins
• 0 Hz to 400 kHz clock frequency
• 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 mA

Signal Buffers, Repeaters, Splitters Applications

• Level translating I2C-bus/SMBus repeater with two voltage supplies
• Enables processor low voltage 2-wire serial bus to interface with standard I2C-bus or SMBus I/O
• Extension of I2C-bus by providing bidirectional buffering for both data (SDA) and clock (SCL) lines

Signal Buffers, Repeaters, Splitters Procurement Notes

Verify the ordering part number PCA9509GM,125 matches the required XQFN8 package variant. Confirm the ambient temperature range is within -40 °C to +85 °C. Ensure the reel packing method corresponds to Reel 7” Q3/T4 with a minimum order quantity of 4000 units as specified in the official documentation.

Signal Buffers, Repeaters, Splitters Selection Notes

Select this component when Port A VCC(A) is at least 1.35 V and Port B VCC(B) is between 3.0 V and 5.5 V. For applications requiring lower voltages, consider the PCA9509A drop-in replacement. Ensure ground offset between PCA9509 and Port A devices does not exceed 50 mV to prevent lock-up conditions.

Signal Buffers, Repeaters, Splitters Part Context

The PCA9509 series includes variants such as PCA9509D (SO8), PCA9509DP (TSSOP8), and PCA9509GM (XQFN8). All variants share identical electrical characteristics and functionality, differing only in package type and physical dimensions. The GM suffix specifically denotes the extremely thin quad flat package with no leads.

Signal Buffers, Repeaters, Splitters Replacement Considerations

PCA9509A serves as a drop-in replacement for applications where Port A VCC(A) is less than 1.35 V or Port B VCC(B) is less than 3.0 V.