TCA9517A
- Two-channel bidirectional buffer
- I2C Bus and SMBus compatible
- Operating supply voltage range of 0.9V to 5.5V on A-side
- Operating supply voltage range of 2.7V to 5.5V on B-side
- Voltage-level translation from 0.9V - 5.5V to 2.7V - 5.5V
- Footprint and functional replacement for PCA9515B
- Active-high repeater-enable input
- Open-drain I2C I/O
- 5.5V Tolerant I2C and enable input support mixed-mode signal operation
- Accommodates standard mode and fast mode I2C devices and multiple controllers
- High-impedance I2C pins when powered-off
- Latch-up performance exceeds 100mA Per JESD 78, class II
- ESD Protection exceeds JESD 22
- 5500V Human-body model (A114-A)
- 200V Machine model (A115-A)
- 1000V Charged-device model (C101)
The TCA9517A is a bidirectional buffer with level shifting capabilities for I2C and SMBus systems. It provides bidirectional voltage-level translation (up-translation/down-translation) between low voltages (down to 0.9V) and higher voltages (2.7V to 5.5V) in mixed-mode applications. This device enables I2C and SMBus systems to be extended without degradation of performance, even during level shifting.
The TCA9517A buffers both the serial data (SDA) and the serial clock (SCL) signals on the I2C bus, thus allowing two buses of up to 400pF bus capacitance to be connected in an I2C application.
The TCA9517A has two types of drivers: A-side drivers and B-side drivers. All inputs and I/Os are over-voltage tolerant to 5.5V, even when the device is unpowered (VCCB and/or VCCA = 0V).
The TCA9517A offers a higher contention level threshold, VILC, than the TCA9517, which allows connections to targets which have weaker pulldown ability.
The type of buffer design on the B-side prevents it from being used in series with devices which use static voltage offset. This is because these devices do not recognize buffered low signals as a valid low and do not propagate it as a buffered low again.
The B-side drivers operate from 2.7V to 5.5V. The output low level for this internal buffer is approximately 0.5V, but the input voltage must be 70mV or more below the output low level when the output internally is driven low. The higher-voltage low signal is called a buffered low. When the B-side I/O is driven low internally, the low is not recognized as a low by the input. This feature prevents a lockup condition from occurring when the input low condition is released.
技術文件
| 重要文件 | 類型 | 標題 | 格式選項 | 下載最新的英文版本 | 日期 | |
|---|---|---|---|---|---|---|
| * | 資料表 | TCA9517A Level-Shifting I2 C Bus Repeater datasheet (Rev. E) | PDF | HTML | 2025/10/7 | ||
| 應用說明 | Understanding Transient Drive Strength vs. DC Drive Strength in Level-Shifters (Rev. A) | PDF | HTML | 2024/7/3 | |||
| 應用說明 | Resolving Improper Implementation of the Static Voltage Offset on I2C Buffers | PDF | HTML | 2023/10/9 | |||
| 應用說明 | Why, When, and How to use I2C Buffers | 2018/5/23 | ||||
| 應用說明 | Choosing the Correct I2C Device for New Designs | PDF | HTML | 2016/9/7 | |||
| 應用說明 | Understanding the I2C Bus | PDF | HTML | 2015/6/30 | |||
| 應用說明 | Maximum Clock Frequency of I2C Bus Using Repeaters | 2015/5/15 | ||||
| 應用說明 | I2C Bus Pull-Up Resistor Calculation | PDF | HTML | 2015/2/13 |
設計與開發
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I2C-DESIGNER — I2C 設計工具
PMP23365 — 具備外部熱插拔及遙測功能的 24V、3A 8 類 PoE PD 參考設計
此參考設計利用 24V 與 3A 輸出實作乙太網路供電 (PoE) 電源裝置 (PD) 主動箝位順向式轉換器。配備整合式脈衝寬度調變器 (PWM) 控制器的 TPS23730 PD 可提供所有必要功能，以實現主動箝位順向式轉換器的 PoE PD 與 PWM 控制。此設計使用二次側調節 (SSR) 和光耦合器回饋。增加外部熱插拔以實現 7 類與 8 類 PD 應用。一次側使用 INA237 來監控 DC/DC 輸入電壓和電流，電源資訊則會由 I2C 隔離器或光耦合器架構電路傳送至二次側。
PMP23366 — 具有平順轉換和遙測功能的雙輸入備援 PoE Class 6 PD 參考設計
此設計實作乙太網路供電 (PoE) 第 6 類供電產品 (PD)，搭載雙備援 PoE 輸入，可在這些輸入與輔助輸入間順暢轉換。使用兩個 TPS2372-3 PD 控制器進行高達 51W 的高功率 PoE 控制。5V 9A 主動箝位順向式轉換器隨 TPS23734 IC 的 PWM 部分實作。INA237A 透過 I2C 提供輸入電壓/電流/功率/溫度量測。
| 封裝 | 針腳 | CAD 符號、佔位空間與 3D 模型 |
|---|---|---|
| VSSOP (DGK) | 8 | Ultra Librarian |
訂購與品質
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