ZHCS791C March 2012 – July 2015 TPS2378
PRODUCTION DATA.
- 1 特性
- 2 應用
- 3 說明
- 4 修訂歷史記錄
- 5 Pin Configuration and Functions
- 6 Specifications
-
7 Detailed Description
- 7.1 Overview
- 7.2 Functional Block Diagram
- 7.3 Feature Description
- 7.4
Device Functional Modes
- 7.4.1 PoE Overview
- 7.4.2 Threshold Voltages
- 7.4.3 PoE Start-up Sequence
- 7.4.4 Detection
- 7.4.5 Hardware Classification
- 7.4.6 Inrush and Start-up
- 7.4.7 Maintain Power Signature
- 7.4.8 Start-up and Converter Operation
- 7.4.9 PD Hotswap Operation
- 7.4.10 Start-up and Power Management, CDB and T2P
- 7.4.11 Adapter ORing
- 7.4.12 Using DEN to Disable PoE
- 7.4.13 ORing Challenges
- 8 Application and Implementation
- 9 Power Supply Recommendations
- 10Layout
- 11器件和文檔支持
- 12機械、封裝和可訂購信息
5 Pin Configuration and Functions
DDA Package
8-Pin HSOP
Top View
Pin Functions
| PIN | I/O | DESCRIPTION | |
|---|---|---|---|
| NAME | NO. | ||
| VDD | 1 | I | Connect to positive PoE input power rail. Bypass with 0.1 µF to VSS. |
| DEN | 2 | I/O | Connect 24.9 kΩ to VDD for detection. Pull to VSS disable pass MOSFET. |
| CLS | 3 | O | Connect resistor from CLS to VSS to program classification current. |
| VSS | 4 | — | Connect to negative power rail derived from PoE source. |
| RTN | 5 | — | Drain of PoE pass MOSFET. |
| CDB | 6 | O | Active low, open-drain converter disable output, referenced to RTN. |
| T2P | 7 | O | Active low indicates type 2 PSE connected or APD active. |
| APD | 8 | I | Raise 1.5 V above RTN to disable pass MOSFET and force T2P active. |
| Pad | — | — | The PowerPad™ must be connected to VSS. A large fill area is required to assist in heat dissipation. |