JAJS381E
September 2009 – September 2018
TPS54218
PRODUCTION DATA.
1
特長
2
アプリケーション
3
概要
Device Images
概略回路図
効率と出力電流との関係
4
改訂履歴
5
概要(続き)
6
Pin Configuration and Functions
Pin Functions
7
Specifications
7.1
Absolute Maximum Ratings
7.2
ESD Ratings
7.3
Recommended Operating Conditions
7.4
Thermal Information
7.5
Electrical Characteristics
7.6
Typical Characteristics
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
Slope Compensation and Output Current
8.3.3
Bootstrap Voltage (Boot) and Low Dropout Operation
8.3.4
Error Amplifier
8.3.5
Voltage Reference
8.3.6
Adjusting the Output Voltage
8.3.7
Enable and Adjusting Undervoltage Lockout
8.3.8
Soft-Start Pin
8.3.9
Sequencing
8.3.10
Constant Switching Frequency and Timing Resistor (RT/CLK Pin)
8.3.11
Overcurrent Protection
8.3.12
Frequency Shift
8.3.13
Reverse Overcurrent Protection
8.3.14
Synchronize Using the RT/CLK Pin
8.3.15
Power Good (PWRGD Pin)
8.3.16
Overvoltage Transient Protection
8.3.17
Thermal Shutdown
8.4
Device Functional Modes
8.4.1
Small Signal Model for Loop Response
8.4.2
Simple Small Signal Model for Peak Current Mode Control
8.4.3
Small Signal Model for Frequency Compensation
9
Application and Implementation
9.1
Application Information
9.2
Typical Application
9.2.1
Design Requirements
9.2.2
Detailed Design Procedure
9.2.2.1
Step One: Select the Switching Frequency
9.2.2.2
Step Two: Select the Output Inductor
9.2.2.3
Step Three: Choose the Output Capacitor
9.2.2.4
Step Four: Select the Input Capacitor
9.2.2.5
Step Five: Minimum Load DC COMP Voltage
9.2.2.6
Step Six: Choose the Soft-Start Capacitor
9.2.2.7
Step Seven: Select the Bootstrap Capacitor
9.2.2.8
Step Eight: Undervoltage Lockout Threshold
9.2.2.9
Step Nine: Select Output Voltage and Feedback Resistors
9.2.2.9.1
Output Voltage Limitations
9.2.2.10
Step 10: Select Loop Compensation Components
9.2.2.11
Power Dissipation Estimate
9.2.3
Application Curves
10
Power Supply Recommendations
11
Layout
11.1
Layout Guidelines
11.2
Layout Example
12
デバイスおよびドキュメントのサポート
12.1
デバイス・サポート
12.1.1
WEBENCH®ツールによるカスタム設計
12.1.2
開発サポート
12.2
商標
12.3
静電気放電に関する注意事項
12.4
Glossary
13
メカニカル、パッケージ、および注文情報
パッケージ・オプション
メカニカル・データ(パッケージ|ピン)
RTE|16
MPQF149D
サーマルパッド・メカニカル・データ
RTE|16
QFND290G
発注情報
jajs381e_oa
jajs381e_pm
9.2.3
Application Curves
Figure 38.
Efficiency vs Load Current
1-A Load Step
Figure 40.
Transient Response
Figure 42.
Power Up, V
OUT
, V
IN
Figure 44.
Power Up, V
OUT
, EN
1.
Figure 46.
SS Discharge During EN Disable / Enable
I
OUT
= 2 A
Figure 48.
Output Ripple
I
OUT
= 2A
Figure 50.
Input Ripple
Figure 52.
Load Regulation vs Load Current
Figure 54.
Regulation vs Input Voltage
Figure 39.
Efficiency vs Load Current
2-A Load Step
Figure 41.
Transient Response
Figure 43.
Power Down, V
OUT
, V
IN
Figure 45.
Power Down, V
OUT
, EN
I
OUT
= 0 A
Figure 47.
Output Ripple
I
OUT
= 0 A
Figure 49.
Input Ripple
V
IN
= 3.3. V
I
OUT
= 2 A
Figure 51.
Closed Loop Response
Figure 53.
Load Regulation vs Load Current