Overview
The TCA9509DGKR, produced by Texas Instruments, is a level-translating I2C and SMBus bus repeater. This integrated circuit is designed to extend I2C and SMBus systems without degrading performance, even during voltage level shifting. It supports bidirectional voltage-level translation between low voltages (down to 0.9V) and higher voltages (2.7V to 5.5V), making it suitable for mixed-mode applications. The device buffers both the serial data (SDA) and the serial clock (SCL) signals, allowing for up to 400pF bus capacitance on the B-side and enabling the isolation of two halves of a bus for voltage and capacitance purposes.
Key Specifications
| Parameter | Description |
|---|---|
| Operating Supply Voltage | 2.7V to 5.5V |
| Level Translation | Down to 0.9V and up to 5.5V |
| Bus Compatibility | I2C and SMBus |
| Buffer Type | Two-channel bidirectional buffer |
| Maximum Bus Capacitance | 400pF on the B-side |
| A-Side Current Source | Integrated 1 mA current source |
| Operating Modes | Standard mode and fast mode I2C |
| Package Type | VSSOP-8-0.65mm |
| RoHS Compliance | Yes |
Key Features
- Two-channel bidirectional buffer for I2C and SMBus signals.
- Level-shifting capabilities between low and high voltages.
- Integrated 1 mA current source on the A-side, eliminating the need for external pull-up resistors.
- Support for standard mode and fast mode I2C.
- Ability to handle up to 400pF bus capacitance on the B-side.
- Overvoltage tolerance to 5.5V on all inputs and B-side I/Os.
- Power-up circuit that keeps output drivers turned off until VCCB is above 2.5V and VCCA is above 0.8V.
Applications
The TCA9509DGKR is suitable for various applications where I2C or SMBus bus extension and level translation are required. These include:
- Mixed-mode systems where different voltage levels are used.
- Systems requiring bus isolation for voltage and capacitance reasons.
- Industrial control systems.
- Consumer electronics.
- Automotive systems.
Q & A
- What is the primary function of the TCA9509DGKR?
The primary function is to act as a level-translating I2C and SMBus bus repeater, extending the bus without performance degradation. - What voltage range does the TCA9509DGKR support?
The device supports an operating supply voltage range of 2.7V to 5.5V. - What types of buses is the TCA9509DGKR compatible with?
The device is compatible with I2C and SMBus. - Does the TCA9509DGKR require external pull-up resistors?
No, it has an integrated 1 mA current source on the A-side, eliminating the need for external pull-up resistors. - What is the maximum bus capacitance the TCA9509DGKR can handle?
The device can handle up to 400pF bus capacitance on the B-side. - Is the TCA9509DGKR RoHS compliant?
Yes, the device is RoHS compliant. - What package type is the TCA9509DGKR available in?
The device is available in a VSSOP-8-0.65mm package. - Does the TCA9509DGKR support fast mode I2C?
Yes, it supports both standard mode and fast mode I2C. - How does the power-up circuit of the TCA9509DGKR work?
The power-up circuit keeps the output drivers turned off until VCCB is above 2.5V and VCCA is above 0.8V. - What is the overvoltage tolerance of the TCA9509DGKR?
All inputs and B-side I/Os are overvoltage tolerant to 5.5V.
