JAJSDM5E September   2017  – November 2019

PRODUCTION DATA.

1. 特長
2. アプリケーション
3. 概要
1.     Device Images
4. 改訂履歴
5. 概要 (続き)
6. Pin Configuration and Functions
7. Specifications
8. Detailed Description
1. 8.1 Overview
2. 8.2 Functional Block Diagram
3. 8.3 Feature Description
4. 8.4 Device Functional Modes
9. Application and Implementation
1. 9.1 Application Information
2. 9.2 Typical Applications
1. 9.2.1 Window Comparator
2. 9.2.2 IR Receiver Analog Front End
3. 9.2.3 Square-Wave Oscillator
10. 10Power Supply Recommendations
11. 11Layout
12. 12デバイスおよびドキュメントのサポート
1. 12.1 デバイス・サポート
1. 12.1.1 開発サポート
2. 12.2 関連リンク
3. 12.3 ドキュメントの更新通知を受け取る方法
4. 12.4 コミュニティ・リソース
5. 12.5 商標
6. 12.6 静電気放電に関する注意事項
7. 12.7 Glossary
13. 13メカニカル、パッケージ、および注文情報

• DPW|5
• DCK|5
• DBV|5
• DPW|5
• DCK|5

9.2.3.2 Detailed Design Procedure

The oscillation frequency is determined by the resistor and capacitor values. The following calculation provides details of the steps.

First consider the output of Figure Figure 44 is high which indicates the inverted input VC is lower than the noninverting input (VA). This causes the C1 to be charged through R4, and the voltage VC increases until it is equal to the noninverting input. The value of VA at the point is calculated by Equation 7.

Equation 7.

if R1 = R2= R3, then VA1 = 2 VCC/ 3

At this time the comparator output trips pulling down the output to the negative rail. The value of VAat this point is calculated by Equation 8.

Equation 8.

if R1 = R2 = R3, then VA2 = VCC/3

The C1 now discharges though the R4, and the voltage VCC decreases until it reaches VA2. At this point, the output switches back to the starting state. The oscillation period equals to the time duration from for C1 from 2VCC/3 to VCC / 3 then back to 2VCC/3, which is given by R4C1 × ln 2 fro each trip. Therefore, the total time duration is calculated as 2 R4C1 × ln 2. The oscillation frequency can be obtained by Equation 9:

Equation 9.