Overview
The PCA9517DG4, produced by Texas Instruments, is a level-translating I2C bus repeater designed to extend I2C and SMBus systems without degrading performance. This BiCMOS integrated circuit operates within a wide voltage range, making it suitable for mixed-mode applications. It buffers both the serial data (SDA) and the serial clock (SCL) signals, allowing the connection of two buses with up to 400-pF bus capacitance. The device is particularly useful for voltage and capacitance isolation in I2C bus systems.
Key Specifications
| Parameter | Specification |
|---|---|
| Operating Supply Voltage Range (A-side) | 0.9 V to 5.5 V |
| Operating Supply Voltage Range (B-side) | 2.7 V to 5.5 V |
| Bus Capacitance | Up to 400 pF per bus |
| Overvoltage Tolerance | Up to 5.5 V (even when unpowered) |
| Enable Input | Active-high with internal pullup to VCCB |
| Operating Temperature Range | -40°C to 85°C |
| Package Types | SOIC (8-pin), VSSOP (8-pin) |
Key Features
- Bidirectional voltage-level translation between low voltages (down to 0.9 V) and higher voltages (2.7 V to 5.5 V)
- Buffers both SDA and SCL signals, allowing connection of two buses with up to 400-pF bus capacitance
- Overvoltage tolerant inputs and I/Os up to 5.5 V, even when unpowered
- Active-high enable input with internal pullup to VCCB
- Supports star topography and series connection of multiple PCA9517s without offset voltage buildup
- Lockup-free operation
- Open-drain I2C I/O
Applications
- Extension of I2C and SMBus systems without performance degradation
- Voltage and capacitance isolation in I2C bus systems
- Mixed-mode applications requiring level translation between different voltage levels
- Systems requiring star or series bus topologies
Q & A
- What is the primary function of the PCA9517DG4?
The PCA9517DG4 is a level-translating I2C bus repeater that buffers SDA and SCL signals to extend I2C and SMBus systems.
- What is the operating supply voltage range for the A-side and B-side of the PCA9517DG4?
The A-side operates from 0.9 V to 5.5 V, and the B-side operates from 2.7 V to 5.5 V.
- What is the maximum bus capacitance supported by the PCA9517DG4?
The device supports up to 400 pF of bus capacitance per bus.
- Is the PCA9517DG4 overvoltage tolerant?
- How does the enable input of the PCA9517DG4 work?
The enable input is active-high with an internal pullup to VCCB.
- Can multiple PCA9517DG4 devices be connected in series or star topology?
- What are the package types available for the PCA9517DG4?
The device is available in SOIC (8-pin) and VSSOP (8-pin) packages.
- What is the operating temperature range of the PCA9517DG4?
The operating temperature range is -40°C to 85°C.
- Does the PCA9517DG4 support clock stretching and arbitration?
No, the PCA9517DG4 does not support clock stretching and arbitration across the repeater.
- How does the power-up circuit of the PCA9517DG4 work?
The power-up circuit keeps the output drivers turned off until VCCB is above 2.5 V and VCCA is above 0.8 V.
