Overview
The PCA9517ADP,118 from NXP USA Inc. is a CMOS integrated circuit designed to provide level shifting between low voltage and higher voltage I²C-bus or SMBus applications. This device enables the translation of signals between two different voltage domains, supporting voltages as low as 0.9 V on one side and up to 5.5 V on the other. It retains all the operating modes and features of the I²C-bus system during level shifts and extends the I²C-bus by providing bidirectional buffering for both the data (SDA) and the clock (SCL) lines.
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| VCC(B) supply voltage | Port B | 2.7 | - | 5.5 | V |
| VCC(A) supply voltage | Port A | 0.9 | - | 5.5 | V |
| ICC(VCC(A)) supply current | - | - | - | 1 | mA |
| ICCH HIGH-level supply current | Both channels HIGH; VCC = 5.5 V; SDAn = SCLn = VCC | - | 1.5 | 5 | mA |
| Output pull-down on port B internal buffer LOW | - | - | - | 0.5 | V |
| Input threshold of the internal buffer | - | - | - | 0.43 | V |
Key Features
- Level shifting between low voltage (down to 0.9 V) and higher voltage (2.7 V to 5.5 V) I²C-bus or SMBus applications.
- Bidirectional buffering for both the data (SDA) and the clock (SCL) lines, enabling extension of the I²C-bus.
- Overvoltage tolerant inputs and I/Os up to 5.5 V, even when the device is unpowered.
- Adjustable voltage bus port A drivers that eliminate static offset voltage, ensuring a LOW on port B translates into a nearly 0 V LOW on port A.
- EN pin for enabling or disabling the drivers under system control.
- Support for star topology with multiple PCA9517As connected in series or in parallel.
Applications
The PCA9517ADP,118 is suitable for various applications requiring level shifting and bus extension in I²C-bus or SMBus systems. These include:
- Embedded systems where different voltage domains need to communicate.
- Industrial control systems requiring robust and reliable communication.
- Automotive systems where voltage levels may vary across different components.
- Consumer electronics that need to interface devices operating at different voltage levels.
Q & A
- What is the primary function of the PCA9517ADP,118?
The primary function is to provide level shifting between low voltage and higher voltage I²C-bus or SMBus applications. - What are the supported voltage ranges for port A and port B?
Port A supports voltages from 0.9 V to 5.5 V, and port B supports voltages from 2.7 V to 5.5 V. - Are the inputs and I/Os overvoltage tolerant?
Yes, the inputs and I/Os are overvoltage tolerant up to 5.5 V, even when the device is unpowered. - Can multiple PCA9517As be connected in series or in parallel?
Yes, multiple PCA9517As can be connected in series or in parallel to support star topology and bus extension. - What is the purpose of the EN pin?
The EN pin is used to enable or disable the drivers under system control. - How does the PCA9517ADP handle static offset voltage?
The adjustable voltage bus port A drivers eliminate static offset voltage, ensuring a LOW on port B translates into a nearly 0 V LOW on port A. - What are the typical applications of the PCA9517ADP,118?
Typical applications include embedded systems, industrial control systems, automotive systems, and consumer electronics. - Can the PCA9517ADP be used in systems with different capacitance requirements?
Yes, it can isolate two halves of a bus for both voltage and capacitance, supporting buses of up to 400 pF. - How does the power-up circuit of the PCA9517ADP work?
The power-up circuit keeps the output driver disabled until the supply voltages are within the specified ranges, ensuring proper startup and operation. - What is the significance of the VCC(A) and VCC(B) pins?
VCC(A) provides the supply voltage for port A, and VCC(B) provides the supply voltage for port B and powers the logic and all I/Os.
