12-75V Input to 10V Output DC-DC Buck Converter

This is a versatile synchronous Buck DC/DC converter built using the LM5007 chip. It operates with an input voltage range 12V to 75V_DC, and provides 10V/250mA output. The regulator can provide load current up to 400mA, but it is advisable to draw only 250mA due to the small thermal area (small PCB). The default output of the converter is set to 10V_dc. The output is adjustable by changing the feedback resistor values R1 and R4. You may refer to the datasheet of the LM5007 chip for more info.

Features

• Operating Input Voltage Range of 12 V to 75 V
• Output 10V @ 250mA (Output Up to 400mA with forced air)
• Adjustable Output Voltage
• High-Efficiency Operation
• Adaptive Constant On-Time Control Architecture
• Ultra-Fast Transient Response
• No Control Loop Compensation Required
• Nearly Constant Switching Frequency
• PWM On-Time Varies Inversely with Input Voltage
• Low Input Quiescent Current
• Inherent Protection Features for Robust Design
• Intelligent Current Limit Protection
• V_CC and Gate Drive U_VLO Protection
• Thermal Shutdown Protection with Hysteresis
• PCB Dimensions 20 x 14.29mm

The LM5007 Step down-switching regulator features all of the functions needed to implement low-cost, efficient, Buck bias regulators. This high-voltage regulator contains an 80V, 0.7A N-channel Buck switch. The regulator is based on a hysteretic control scheme using an on-time inversely proportional to input voltage (VIN). This feature allows the operating frequency to remain relatively constant with load and input voltage variations. The hysteretic control requires no control loop compensation while providing fast load transient response. Additional protection features include: Thermal Shutdown, VCC undervoltage lockout, and maximum duty–cycle limiter. LM5007 can be used in numerous applications to efficiently regulate step-down higher voltage input This regulator is well suited for 48V telecom and the new 42V automotive power bus ranges. The LM5007 operates in discontinuous conduction mode at light load currents or continuous conduction mode at heavier load currents. In discontinuous conduction mode, current through the output inductor starts at zero, ramps up to the peak value during the buck switch on time, and then back to zero during buck switch-off time. In discontinuous conduction mode, the operating frequency can be relatively low and will vary with load. Therefore, at light loads, the conversion efficiency is maintained, since switching losses decrease with reduction in switching frequency.

Connections

• Pin 1 = Voltage Input 12V to 75V
• Pin 2 = NC
• Pin 3 = GND
• Pin 4 = NC
• Pin 5 = Output 10V, 250mA

Schematic

Parts List

Connections

Gerber View

Photos

Video

LM5007 Datasheet

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