DC/DC Conversion Step-Down (Buck) Switch Mode Power Converter Applications
The purpose of this module is to help you to design different low-power applications and provide insight on how simple synchronous buck converters can be used to develop solutions for non-typical requirements. The following provides examples of converter applications that fulfill a variety of industry requirements.
MCP16311/2 30 V Input, High-Efficiency, Integrated Synchronous Buck Regulator
The MCP16311 is a compact, high-efficiency, fixed-frequency Pulse Width Modulation/Pulse Frequency Modulation (PWM/PFM), synchronous step-down DC-DC converter in an 8-pin MSOP or 2 × 3 Thin Dual Flat No Leads (TDFN) package that operates from input voltage sources up to 30V. Integrated features include a high-side and a low-side switch, fixed-frequency Peak Current mode control, internal compensation, peak current limit and overtemperature protection. The MCP16311 provides all the active functions for local DC-DC conversion, with fast transient response and accurate regulation.
• PIC®/dsPIC® Microcontroller Bias Supply
• 24V Industrial Input DC-DC Conversion
• General Purpose DC-DC Conversion
• Local Point of Load Regulation
• Automotive Battery Regulation
• Set-Top Boxes
• Cable Modems
• Wall Transformer Regulation
• Laptop Computers
• Networking Systems
• AC-DC Digital Control Bias
• Distributed Power Supplies
MCP16311 Synchronous Buck Regulator Application Circuit Example
This circuit example offers up to 95 percent efficiency with a wide input voltage range (4.5V to 30V) and steps down to 3.3V at 1A output. Output voltage can be adjusted to a wide range from 2V to 24V. The integrated N-channel low and high-side switches offer low RDSon at 170 mΩ and 300 mΩ. While the PCP16311 offer automatic pulse-frequency modulation/pulse-width modulation (PFM/PWM) operation, its shutdown and quiescent current are only at 3 μA and 44 μA respectively. The following diagrams show the MCP16311 output current capability and efficiency, with and without PFM Operation enabled.
CBOOST should be placed between the boost pin (BOOST) and the switch node pin. This leaves space close to the MCP16311/2 VFB pin to the feedback resistors. The feedback loop must be routed away from the switch node, so noise is not coupled into the high-impedance VFB input.
MCP16311/2 Synchronous Buck Evaluation Board ( ADM00467 )
The MCP16311/2 Synchronous Buck Converter Evaluation Board is used to evaluate and demonstrate Microchip's MCP16311/2 products. This board demonstrates the MCP16311 and MCP16312 in two Buck converter applications with two output voltages.