Overview
The PCA9515B, produced by Texas Instruments, is a BiCMOS dual bidirectional buffer integrated circuit designed for I2C bus and SMBus applications. This device is intended to extend I2C and similar bus systems without degrading system performance. It contains two identical bidirectional open-drain buffer circuits that buffer both the serial data (SDA) and serial clock (SCL) signals on the I2C bus, retaining all the operating modes and features of the I2C system. The PCA9515B operates within a voltage range of 2.3 V to 3.6 V and supports both Standard Mode (100-kHz) and Fast Mode (400-kHz) I2C operations.
Key Specifications
| Parameter | Min | Max | Unit |
|---|---|---|---|
| VCC Supply Voltage | 2.3 | 3.6 | V |
| VIH High-Level Input Voltage (SDA and SCL inputs) | 0.7 × VCC | 5.5 | V |
| VIL Low-Level Input Voltage (SDA and SCL inputs) | -0.5 | 0.3 × VCC | V |
| VILc Low-Level Input Voltage Contention (SDA and SCL inputs) | -0.5 | 0.4 | V |
| IOL Low-Level Output Current (VCC = 2.3 V) | 6 | mA | |
| TA Operating Free-Air Temperature | -40 | 85 | °C |
| ESD Protection (Human-Body Model) | 2000 | V | |
| ESD Protection (Charged-Device Model) | 1000 | V |
Key Features
- I2C Bus and SMBus Compatible
- Support for I2C Standard Mode (100-kHz) and Fast Mode (400-kHz)
- Active-High Repeater-Enable Input with internal pull-up to VCC
- Open-Drain I2C Input and Output
- 5.5-V Tolerant I2C Input and Output and Enable Input
- Mixed-Mode Signal Operation Support
- Lockup-Free Operation
- Accommodates Standard Mode, Fast Mode I2C Devices, and Multiple Masters
- Supports Arbitration and Clock Stretching Across Repeater
- Powered-Off High-Impedance I2C Pins
- Latch-Up Performance Exceeds 100-mA Per JESD 78, Class I
- Bidirectional Voltage-Level Translation (up-translation and down-translation) between low voltages (down to 2.3 V) and higher voltages (up to 5.5 V)
Applications
- Servers
- Routers (Telecom Switching Equipment)
- Industrial Equipment
- Products with Many I2C Slaves and Long PCB Traces
The PCA9515B is typically used to buffer I2C signals, isolating capacitance from two sides of the bus. This allows for longer traces and cables, and more robust I2C communication. It can also be used to operate two buses at different voltage levels (e.g., 3.3 V and 5 V) and at different frequencies (100 kHz and 400 kHz).
Q & A
- What is the PCA9515B used for?
The PCA9515B is used to extend I2C and SMBus systems without degrading performance by buffering the serial data (SDA) and serial clock (SCL) signals.
- What are the supported I2C modes?
The PCA9515B supports both I2C Standard Mode (100-kHz) and Fast Mode (400-kHz).
- What is the voltage range for the PCA9515B?
The PCA9515B operates within a voltage range of 2.3 V to 3.6 V.
- What is the purpose of the active-high enable input?
The active-high enable input allows users to select when the repeater is active and isolate malfunctioning slaves on power-up reset.
- Can the PCA9515B handle different voltage levels on the two buses?
Yes, the PCA9515B supports bidirectional voltage-level translation between low voltages (down to 2.3 V) and higher voltages (up to 5.5 V).
- What are the ESD protection ratings for the PCA9515B?
The PCA9515B has ESD protection exceeding 2000 V for the Human-Body Model and 1000 V for the Charged-Device Model.
- Can multiple PCA9515B devices be used in series?
No, two or more PCA9515B devices cannot be used in series due to potential lockup conditions.
- What is the recommended operating temperature range for the PCA9515B?
The recommended operating temperature range is from -40°C to 85°C.
- What type of input and output configuration does the PCA9515B have?
The PCA9515B has open-drain I2C input and output configurations.
- How does the PCA9515B handle arbitration and clock stretching?
The PCA9515B supports arbitration and clock stretching across the repeater.
- What are some typical applications of the PCA9515B?
Typical applications include servers, routers, industrial equipment, and products with many I2C slaves and long PCB traces.
