ZHCSFB5D July 2016 – December 2017 LM5141-Q1
PRODUCTION DATA.
- 1 特性
- 2 應用
- 3 說明
- 4 修訂歷史記錄
- 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器件和文檔支持
- 12機械、封裝和可訂購信息
8.2.2.6 Control Loop
The open loop gain is defined as the product of modulator transfer function and feedback transfer function. When plotted on a dB scale, the open loop gain is shown as the sum of modulator gain and feedback gain.
DC modulator gain is:
The modulator gain plus power stage transfer function with an embedded current loop is show in Equation 50. The equation includes the sample gain at FSW /2 (ωn), which is caused by sampling effect of current mode control.
Because the loop crossover frequency is well below sample gain effects, Equation 50 can be simplified as one pole and a one zero system as shown in Equation 51.
RLOAD is the load resistance
RDCR is the dc resistance on the output inductor which is 8.1 mΩ
RSENSE is the current sense resistance which is 9 mΩ