ZHCSG23A March 2017 – February 2018 LM25141-Q1
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
-
7 Detailed Description
- 7.1 Overview
- 7.2 Functional Block Diagram
- 7.3
Feature Description
- 7.3.1 High Voltage Start-Up Regulator
- 7.3.2 VCC Regulator
- 7.3.3 Oscillator
- 7.3.4 Synchronization
- 7.3.5 Frequency Dithering (Spread Spectrum)
- 7.3.6 Enable
- 7.3.7 Power Good
- 7.3.8 Output Voltage
- 7.3.9 Current Sense
- 7.3.10 DCR Current Sensing
- 7.3.11 Error Amplifier and PWM Comparator
- 7.3.12 Slope Compensation
- 7.3.13 Hiccup Mode Current Limiting
- 7.3.14 Standby Mode
- 7.3.15 Soft Start
- 7.3.16 Diode Emulation
- 7.3.17 High- and Low-Side Drivers
-
8 Application and Implementation
- 8.1 Application Information
- 8.2 Typical Application
- 9 Power Supply Recommendations
- 10Layout
- 11器件和文档支持
- 12机械、封装和可订购信息
8.2.2.5.4 Frequency Dithering
Figure 33 shows the CISPR 25 Class 5 conducted emission test run on the LM25141-Q1EVM, without the Dither feature enabled. The first harmonic (peak measurement) is 48 dBµV, Figure 34 shows the conducted emissions test results with the Dither feature enabled. With the Dither featured enabled, the first harmonic (peak measurement) was lowered to 40 dBµV, an 8-dB reduction.
Figure 33. CISPR 25 Class 5 Conducted EMI, Without Dither
Figure 34. CISPR 25 Class 5 With Dither