JAJSBZ4B June   2014  – January 2018

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. Pin Configuration and Functions
6. Specifications
7. Detailed Description
1. 7.1 Overview
2. 7.2 Functional Block Diagram
3. 7.3 Feature Description
4. 7.4 Device Functional Modes
8. Applications and Implementation
1. 8.1 Application Information
2. 8.2 Typical Applications
1. 8.2.1 Design Requirements
2. 8.2.2 Detailed Design Procedure
3. 8.2.3 Application Curves
9. Power Supply Recommendations
10. 10Layout
1. 10.1 Layout Guidelines
2. 10.2 Layout Example
11. 11デバイスおよびドキュメントのサポート
1. 11.1 デバイス・サポート
1. 11.1.1 開発サポート
2. 11.2 ドキュメントの更新通知を受け取る方法
3. 11.3 コミュニティ・リソース
4. 11.4 商標
5. 11.5 静電気放電に関する注意事項
6. 11.6 Glossary
12. 12メカニカル、パッケージ、および注文情報

• PWP|16
• PWP|16

8.2.2.12 Undervoltage Lockout Setpoint

The undervoltage lockout (UVLO) is adjusted using the external voltage divider network of RENT and RENB. RENT is connected between VIN and the EN pin of the LM46001 device. RENB is connected between the EN pin and the GND pin. The UVLO has two thresholds, one for power up when the input voltage is rising and one for power down or brownouts when the input voltage is falling. Use Equation 24 to determine the rising VIN (UVLO) level:

Equation 24. VIN-UVLO-RISING = VENH × (RENB + RENT) / RENB

The EN rising threshold for LM46001 is set to be 2.1 V. Choose the value of RENB to be 1 MΩ to minimize input current going into the converter. If the desired VIN (UVLO) level is at 5 V, then the value of RENT can be calculated using Equation 25:

Equation 25. RENT = (VIN-UVLO-RISING / VENH – 1) × RENB

Equation 25 yields a value of 1.37 MΩ. The resulting falling UVLO threshold can be calculated by Equation 26:

Equation 26. VIN-UVLO-FALLING = 1.8 × (RENB + RENT) / RENB