ZHCSIY8C October 2018 – June 2021 LM5143-Q1
PRODUCTION DATA
- 1 特性
- 2 应用
- 3 说明
- 4 Revision History
- 5 说明（续）
- 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 Input Voltage Range (VIN)
- 8.3.2 High-Voltage Bias Supply Regulator (VCC, VCCX, VDDA)
- 8.3.3 Enable (EN1, EN2)
- 8.3.4 Power Good Monitor (PG1, PG2)
- 8.3.5 Switching Frequency (RT)
- 8.3.6 Clock Synchronization (DEMB)
- 8.3.7 Synchronization Out (SYNCOUT)
- 8.3.8 Spread Spectrum Frequency Modulation (DITH)
- 8.3.9 Configurable Soft Start (SS1, SS2)
- 8.3.10 Output Voltage Setpoint (FB1, FB2)
- 8.3.11 Minimum Controllable On-Time
- 8.3.12 Error Amplifier and PWM Comparator (FB1, FB2, COMP1, COMP2)
- 8.3.13 Slope Compensation
- 8.3.14 Inductor Current Sense (CS1, VOUT1, CS2, VOUT2)
- 8.3.15 Hiccup Mode Current Limiting (RES)
- 8.3.16 High-Side and Low-Side Gate Drivers (HO1/2, LO1/2, HOL1/2, LOL1/2)
- 8.3.17 Output Configurations (MODE, FB2)
- 8.4 Device Functional Modes
-
9 Application and Implementation
- 9.1 Application Information
- 9.2 Typical Applications
- 10Power Supply Recommendations
- 11Layout
- 12Device and Documentation Support
- 13Mechanical, Packaging, and Orderable Information
9.2.1 Design 1 – High Efficiency, Dual-Output Buck Regulator for Automotive Applications
Figure 9-4 shows the schematic diagram of a dual-output synchronous buck regulator with output voltages setpoints of 3.3 V and 5 V and a rated load current of 7 A for each output. In this example, the target half-load and full-load efficiencies are 91% and 90%, respectively, based on a nominal input voltage of 12 V that ranges from 3.5 V to 36 V. The switching frequency is set at 2.1 MHz by resistor RRT. The 5-V output is connected to VCCX to reduce IC bias power dissipation and improve efficiency.
Figure 9-4 Application Circuit 1 With LM5143-Q1 Buck Regulator at 2.1 MHzThis and subsequent design examples are provided herein to showcase the LM5143-Q1 controller in several different applications. Depending on the source impedance of the input supply bus, an electrolytic capacitor can be required at the input to ensure stability, particularly at low input voltage and high output current operating conditions. See Section 10 for more details.