Overview
The PCA9509DP,118 is a level-translating I2C-bus/SMBus repeater developed by NXP Semiconductors. This device is designed to facilitate communication between I2C circuits operating at different voltage levels, making it particularly useful in mixed-voltage environments. It enables low-voltage microcontrollers to interface with standard 5V I2C peripherals and supports extended I2C bus lengths and higher capacitance.
Key Specifications
| Attribute | Specification |
|---|---|
| Interface Type | I2C/SMBus |
| No of Channels | 2 |
| Clock Frequency - Max | 400 kHz |
| Supply Voltage - Nom | 3 V to 5.5 V |
| Supply Current | 0.25 mA to 5 mA |
| Package Style | TSSOP-8 |
| Mounting Method | Surface Mount |
| Operating Temperature | -40°C to 85°C |
Key Features
- Bidirectional buffer isolates capacitance and allows 400 pF on port B of the device.
- Voltage level translation from port A (1.0 V [as low as 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.
Applications
The PCA9509DP,118 is particularly useful in systems that require communication between I2C devices operating at different voltage levels. It is advantageous in scenarios such as:
- Interfacing low-voltage microcontrollers with standard 5V I2C peripherals.
- Extending I2C bus lengths and handling higher capacitance.
- Mixed-voltage environments where communication between different voltage levels is essential.
Q & A
- What is the primary function of the PCA9509DP,118?
The PCA9509DP,118 is a level-translating I2C-bus/SMBus repeater that enables communication between I2C circuits operating at different voltage levels.
- What are the voltage ranges supported by the PCA9509DP,118?
The device supports a low-voltage side ranging from 1.0 V (as low as 0.95 V in special cases) to VCC(B) - 1.0 V and a high-voltage side ranging from 3.0 V to 5.5 V.
- What is the maximum clock frequency supported by the PCA9509DP,118?
The maximum clock frequency supported is 400 kHz.
- Does the PCA9509DP,118 require external pull-up resistors?
No, it does not require external pull-up resistors on the lower voltage port A due to its internal current source.
- What is the package style of the PCA9509DP,118?
The package style is TSSOP-8.
- What is the operating temperature range of the PCA9509DP,118?
The operating temperature range is -40°C to 85°C.
- How does the PCA9509DP,118 handle capacitance on the I2C bus?
The device isolates capacitance and allows up to 400 pF on port B.
- Does the PCA9509DP,118 support multiple masters on the I2C bus?
Yes, it supports Standard-mode and Fast-mode I2C-bus devices and multiple masters.
- What happens to the I2C-bus pins when the PCA9509DP,118 is unpowered?
The I2C-bus pins are high-impedance when the device is unpowered.
- How should the PCA9509DP,118 be handled to prevent damage?
The device requires careful handling and appropriate ESD protection measures during handling and installation to preserve its integrity and functionality.
