ZHCSIJ1E June 1999 – July 2018 LM2574 , LM2574HV
PRODUCTION DATA.
- 1 特性
- 2 应用
- 3 说明
- 4 修订历史记录
- 5 Pin Configuration and Functions
-
6 Specifications
- 6.1 Absolute Maximum Ratings
- 6.2 ESD Ratings
- 6.3 Recommended Operating Conditions
- 6.4 Thermal Information
- 6.5 Electrical Characteristics for All Output Voltage Versions
- 6.6 Electrical Characteristics – 3.3-V Version
- 6.7 Electrical Characteristics – 5-V Version
- 6.8 Electrical Characteristics – 12-V Version
- 6.9 Electrical Characteristics – 15-V Version
- 6.10 Electrical Characteristics – Adjustable Version
- 6.11 Typical Characteristics
- 7 Detailed Description
-
8 Application and Implementation
- 8.1 Application Information
- 8.2 Typical Applications
- 9 Power Supply Recommendations
- 10Layout
- 11器件和文档支持
- 12机械、封装和可订购信息
8.1.1 Input Capacitor (CIN)
To maintain stability, the regulator input pin must be bypassed with at least a 22-μF electrolytic capacitor. The leads of the capacitor must be kept short, and located near the regulator.
If the operating temperature range includes temperatures below −25°C, the input capacitor value may need to be larger. With most electrolytic capacitors, the capacitance value decreases and the ESR increases with lower temperatures and age. Paralleling a ceramic or solid tantalum capacitor increases the regulator stability at cold temperatures. For maximum capacitor operating lifetime, the RMS ripple current rating of the capacitor must be greater than Equation 2.
Equation 2. 
where
for a buck regulator
for a buck-boost regulator