ZHCS165B April 2011 – October 2014 TPS55010
PRODUCTION DATA.
- 1 特性
- 2 應用
- 3 說明
- 4 簡化電路原理圖
- 5 修訂歷史記錄
- 6 Pin Configuration and Functions
- 7 Specifications
-
8 Detailed Description
- 8.1 Overview
- 8.2 Functional Block Diagram
- 8.3
Feature Description
- 8.3.1 Fixed Frequency PWM Control
- 8.3.2 Half Bridge and Bootstrap Voltage
- 8.3.3 Error Amplifier
- 8.3.4 Voltage Reference
- 8.3.5 Adjusting the Output Voltage
- 8.3.6 Enable and Adjusting Undervoltage Lockout
- 8.3.7 Adjusting Slow Start Time
- 8.3.8 Constant Switching Frequency and Timing Resistor (RT/CLK Pin)
- 8.3.9 How to Interface to RT/CLK Pin
- 8.3.10 Overcurrent Protection
- 8.3.11 Reverse Overcurrent Protection
- 8.3.12 FAULT Pin
- 8.3.13 Thermal Shutdown
- 8.4 Device Functional Modes
-
9 Application And Implementation
- 9.1 Application Information
- 9.2
Typical Applications
- 9.2.1 Design Guide - Step-by-Step Design Procedure
- 9.2.2 Primary Side Voltage
- 9.2.3 Voltage Feedback
- 9.2.4 Selecting the Switching Frequency and Primary Inductance
- 9.2.5 Primary Side Capacitor
- 9.2.6 Secondary Side Diode
- 9.2.7 Secondary Side Capacitor
- 9.2.8 Input Capacitor
- 9.2.9 Y - Capacitor
- 9.2.10 Slow Start Capacitor
- 9.2.11 Bootstrap Capacitor Selection
- 9.2.12 UVLO Resistors
- 9.2.13 Compensation
- 9.2.14 Design Tips
- 9.2.15 How to Specify a Fly-Buck Transformer
- 9.2.16 Application Curves
- 9.3 Typical Application, Dual Output
- 10Power Supply Recommendations
- 11Layout
- 12器件和文檔支持
- 13機械封裝和可訂購信息
11 Layout
11.1 Layout Guidelines
Layout is a critical portion of good power supply design. There are several signal paths that conduct fast changing currents or voltages that can interact with stray inductance or parasitic capacitance to generate noise or degrade the power supplies performance. Care should be taken to minimize the loop area formed by the bypass capacitor connections and the VIN pins. See Figure 55 for a PCB layout example. The GND pins should be tied directly to the thermal pad under the IC. The power pad should be connected to any internal PCB ground planes using multiple vias directly under the IC. Additional vias can be used to connect the top side ground area to the internal planes near the input and output capacitors.
- Locate the input bypass capacitor as close to the IC as possible.
- The PH pin should be routed to the primary side of the transformer.
- Since the PH connection is the switching node, the transformer should be located close to the PH pins, and the area of the PCB conductor minimized to prevent excessive capacitive coupling.
- The boot capacitor must also be located close to the device.
- The sensitive analog ground connections for the feedback voltage divider, compensation component, slow start capacitor and frequency set resistor should be connected to a separate analog ground trace as shown.
- The RT/CLK pin is particularly sensitive to noise so the RT resistor should be located as close as possible to the IC and routed with minimal lengths of trace. Avoid connecting y capacitor on nodes which experience high dv/dt.
11.2 Layout Example
Figure 55. PCB Layout Example