ZHCSLD0B May 2020 – June 2021 LM62435-Q1
PRODUCTION DATA
- 1 特性
- 2 應用
- 3 說明
- 4 Revision History
- 5 Device Comparison Table
- 6 Pin Configuration and Functions
- 7 Specifications
-
8 Detailed Description
- 8.1 Overview
- 8.2 Functional Block Diagram
- 8.3
Feature Description
- 8.3.1 EN Uses for Enable and VIN UVLO
- 8.3.2 MODE/SYNC Pin Operation
- 8.3.3 PGOOD Output Operation
- 8.3.4 Internal LDO, VCC UVLO, and BIAS Input
- 8.3.5 Bootstrap Voltage and VCBOOT-UVLO (CBOOT Pin)
- 8.3.6 Adjustable SW Node Slew Rate
- 8.3.7 Spread Spectrum
- 8.3.8 Soft Start and Recovery From Dropout
- 8.3.9 Output Voltage Setting
- 8.3.10 Overcurrent and Short Circuit Protection
- 8.3.11 Thermal Shutdown
- 8.3.12 Input Supply Current
- 8.4 Device Functional Modes
- 9 Application and Implementation
- 10Power Supply Recommendations
- 11Layout
- 12Device and Documentation Support
- 13Mechanical, Packaging, and Orderable Information
8.4.3.2.1 Diode Emulation
Diode emulation prevents reverse current through the inductor which requires a lower frequency needed to regulate given a fixed peak inductor current. Diode emulation also limits ripple current as frequency is reduced. With a fixed peak current, as output current is reduced to zero, frequency must be reduced to near zero to maintain regulation.
The device has a minimum peak inductor current setting while in auto mode.Once current is reduced to a low value with fixed input voltage, on-time is constant. Regulation is then achieved by adjusting frequency. This mode of operation is called PFM mode regulation.