ZHCSI27C April 2018 – October 2021 LM5036
PRODUCTION DATA
- 1 特性
- 2 應用
- 3 說明
- 4 Revision History
- 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 Undervoltage Lockout (UVLO)
- 7.3.3 Reference Regulator
- 7.3.4 Oscillator, Synchronized Input
- 7.3.5 Voltage-Mode Control
- 7.3.6 Primary-Side Gate Driver Outputs (LSG and HSG)
- 7.3.7 Half-Bridge PWM Scheme
- 7.3.8 Maximum Duty Cycle Operation
- 7.3.9 Pre-Biased Start-Up Process
- 7.3.10 Zero Duty Cycle Operation
- 7.3.11 Enhanced Cycle-by-Cycle Current Limiting with Pulse Matching
- 7.3.12 Reverse Current Protection
- 7.3.13 CBC Threshold Accuracy
- 7.3.14 Hiccup Mode Protection
- 7.3.15 Hiccup Mode Blanking
- 7.3.16 Over-Temperature Protection (OTP)
- 7.3.17 Over-Voltage / Latch (ON_OFF Pin)
- 7.3.18 Auxiliary Constant On-Time Control
- 7.3.19 Auxiliary On-Time Generator
- 7.3.20 Auxiliary Supply Current Limiting
- 7.3.21 Auxiliary Primary Output Capacitor Ripple
- 7.3.22 Auxiliary Ripple Configuration and Control
- 7.3.23 Asynchronous Mode Operation of Auxiliary Supply
- 7.4 Device Functional Modes
-
8 Application and Implementation
- 8.1 Application Information
- 8.2
Typical Application
- 8.2.1 Design Requirements
- 8.2.2
Detailed Design Procedure
- 8.2.2.1 Custom Design With WEBENCH? Tools
- 8.2.2.2 Input Transient Protection
- 8.2.2.3 Level-Shift Detection Circuit
- 8.2.2.4 Applications with VIN > 100-V
- 8.2.2.5 Applications without Pre-Biased Start-Up Requirement
- 8.2.2.6 UVLO Voltage Divider Selection
- 8.2.2.7 Over Voltage, Latch (ON_OFF Pin) Voltage Divider Selection
- 8.2.2.8 SS Capacitor
- 8.2.2.9 SSSR Capacitor
- 8.2.2.10 Half-Bridge Power Stage Design
- 8.2.2.11 Current Limit
- 8.2.2.12 Auxiliary Transformer
- 8.2.2.13 Auxiliary Feedback Resistors
- 8.2.2.14 RON Resistor
- 8.2.2.15 VIN Pin Capacitor
- 8.2.2.16 Auxiliary Primary Output Capacitor
- 8.2.2.17 Auxiliary Secondary Output Capacitor
- 8.2.2.18 Auxiliary Feedback Ripple Circuit
- 8.2.2.19 Auxiliary Secondary Diode
- 8.2.2.20 VCC Diode
- 8.2.2.21 Opto-Coupler Interface
- 8.2.2.22 Full-Bridge Converter Applications
- 8.2.3 Application Curves
- 9 Power Supply Recommendations
- 10Layout
- 11Device and Documentation Support
- 12Mechanical, Packaging, and Orderable Information
8.2.2.4 Applications with VIN > 100-V
For applications where the input voltage exceeds 100-V, all of the 100V-rated internal circuit blocks, including VCC start-up regulator, auxiliary supply and half-bridge gate drivers, need to be bypassed, or powered from a reduced voltage. In this case, VIN pin can be powered from an external start-up regulator, as shown in Figure 8-4. If pre-biased start-up is required the integrated flybuck aux circuit should be used from the reduced VIN pin voltage to supply the secondary control circuit. If pre-biased start-up is not required, the bias supply VAUX1, can be derived from an external auxiliary supply. An external gate driver with higher voltage rating should be used to drive the half bridge.
Figure 8-4 External Start-Up Regulator