SNAS879 December 2024 LMR60420
PRODMIX
- 1
- 1 Features
- 2 Applications
- 3 Description
- 4 Device Comparison Table
- 5 Pin Configuration and Functions
- 6 Specifications
- 7 Detailed Description
-
8 Application and
Implementation
- 8.1 Application Information
- 8.2
Typical Application
- 8.2.1 Design Requirements
- 8.2.2 Detailed Design Procedure
- 8.2.3 Application Curves
- 8.3 Power Supply Recommendations
- 8.4 Layout
- 9 Device and Documentation Support
- 10Revision History
- 11Mechanical, Packaging, and Orderable Information
封裝選項(xiàng)
機(jī)械數(shù)據(jù) (封裝 | 引腳)
- RAK|9
散熱焊盤機(jī)械數(shù)據(jù) (封裝 | 引腳)
訂購(gòu)信息
7.4.2.1 Continuous Conduction Mode (CCM)
In CCM, the LMR60420 supplies a regulated output voltage by turning on the internal high-side (HS) and low-side (LS) switches with varying duty cycle (D). During the HS switch on time, the SW pin voltage, VSW, swings up to approximately VIN, and the inductor current, iL, increases with a linear slope. The HS switch is turned off by the control logic. During the HS switch off time, tOFF, the LS switch is turned on. Inductor current discharges through the LS switch, which forces the VSW to swing below ground by the voltage drop across the LS switch. The converter loop adjusts the duty cycle to maintain a constant output voltage. D is defined by the on time of the HS switch over the switching period:
In an ideal buck converter where losses are ignored, D is proportional to the output voltage and inversely proportional to the input voltage:
Figure 7-6 SW Voltage and Inductor Current Waveforms in Continuous Conduction Mode (CCM)