Overview
The PCA9518PWR, produced by Texas Instruments, is an expandable five-channel bidirectional buffer designed for I2C and SMBus applications. This device is particularly useful in systems where the I2C bus capacitance needs to be managed, as it separates and buffers the I2C data (SDA) and clock (SCL) lines into multiple segments, each with a maximum bus capacitance of 400 pF. This allows for the extension of the I2C bus without compromising system performance. The PCA9518PWR operates within a voltage range of 3 V to 3.6 V and features 5-V tolerant I2C and enable input pins, enabling mixed-mode signal operation.
Key Specifications
| Parameter | Value |
|---|---|
| Package | TSSOP-20 |
| Pins | 20 |
| Operating Temperature Range | -40°C to 85°C |
| Supply Voltage Range | 3 V to 3.6 V |
| Maximum Clock Frequency | 400 kHz |
| I2C and Enable Input Pins | 5-V tolerant |
| ESD Protection | 2000-V Human-Body Model, 200-V Machine Model, 1000-V Charged-Device Model |
| Latchup Performance | Exceeds 100 mA per JESD 78 |
Key Features
- Expandable five-channel bidirectional buffer for I2C and SMBus applications.
- 400-kHz fast I2C bus support.
- Operating VCC range of 3 V to 3.6 V with 5-V tolerant I2C and enable input pins.
- Active-high individual repeater enable inputs.
- Open-drain input/outputs.
- Lockup-free operation and supports multiple masters.
- Powered-off high-impedance I2C pins.
- I2C bus and SMBus compatible.
- Internal power-on-reset circuit (VPOR).
- Four open-drain I/O pins for expansion.
Applications
The PCA9518PWR is suitable for various applications requiring the extension and buffering of I2C and SMBus signals. These include:
- Industrial control systems where multiple I2C devices need to be connected over long distances.
- Automotive systems requiring robust and reliable I2C communication.
- Consumer electronics such as TVs, set-top boxes, and other multimedia devices.
- Medical devices that require reliable and noise-immune I2C communication.
Q & A
- What is the primary function of the PCA9518PWR?
The PCA9518PWR is an expandable five-channel bidirectional buffer for I2C and SMBus applications, designed to manage and extend the I2C bus. - What is the operating voltage range of the PCA9518PWR?
The device operates within a voltage range of 3 V to 3.6 V. - Is the PCA9518PWR compatible with 5-V systems?
Yes, it has 5-V tolerant I2C and enable input pins to support mixed-mode signal operation. - What is the maximum clock frequency supported by the PCA9518PWR?
The device supports a maximum clock frequency of 400 kHz. - Does the PCA9518PWR support clock stretching across the repeater?
No, the PCA9518PWR does not support clock stretching across the repeater. - How does the PCA9518PWR handle ESD protection?
The device exceeds ESD protection standards of 2000-V Human-Body Model, 200-V Machine Model, and 1000-V Charged-Device Model. - Can multiple PCA9518PWR devices be connected in series?
No, multiple PCA9518PWR devices should not be connected in series; instead, they can be grouped into clusters using the expansion pins. - What type of resistors are required for the PCA9518PWR?
Pullup resistors are required on each SDA and SCL line to provide the logic high levels on the buffered bus. - Is the PCA9518PWR compatible with standard-mode and fast-mode I2C devices?
Yes, the device is designed to work with both standard-mode and fast-mode I2C devices, as well as SMBus devices. - What is the purpose of the internal power-on-reset circuit (VPOR) in the PCA9518PWR?
The internal power-on-reset circuit allows for an initial condition and the ramping of VCC to set the internal logic.
