1.2V to 50V @ 3A – Adjustable Power Supply with 55Vdc Input

The project presented here is a wide input voltage range non-isolated DC-DC Converter, that provides a regulated, adjustable output voltage. The operating input supply is 55V DC and output regulated from 1.2V to 50V DC. The project built using LM2576HVT-ADJ IC. Screw terminals provided for easy input and output connections, onboard power LED at the input, bridge rectifier for AC/DC Input, an onboard potentiometer to adjust the output voltage, etc. This is a low-profile board with a thermal area on PCB that acts as a heatsink. An additional LC filter using C5 and L2 that reduces the output ripple by a factor of 10 or more is included in this circuit. The device has a current limiting feature to prevent the switching current from exceeding a safe value during an accidental overload on output.

LM2576 Description

The LM2576 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving 3-A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3 V, 5 V, 12 V, 15 V, and an adjustable output version. Requiring a minimum number of external components, these regulators are simple to use and include fault protection and a fixed-frequency oscillator. The LM2576 series offers a high-efficiency replacement for popular three-terminal linear regulators. It substantially reduces the size of the heat sink, and in some cases, no heat sink is required. A standard series of inductors optimized for use with the LM2576 are available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies. Other features include a ±4% tolerance on output voltage within specified input voltages and output load conditions, and ±10% on the oscillator frequency. External shutdown is included, featuring 50-µA (typical) standby current. The output switch includes cycle-by-cycle current limiting, as well as thermal shutdown for full protection under fault conditions.

Features

• Input voltage 55V (it can work with Lower Input DC Supply, but the output will be lower)
• Bridge Rectifier at the input so No polarity issue in DC input
• Adjustable version output voltage range: 1.23 V to 50 V ±4% maximum over line and load conditions
• 3A output current (Maximum)
• Cycle-by-Cycle Peak Current Limit for Overload Protection
• Power LED at input
• Onboard Potentiometer for Output Voltage Adjust
• Screw Terminal for Inputs and Output Connection
• Additional Inductor and Capacitor to reduce the Ripple
• 52-kHz Fixed-frequency internal oscillator
• Thermal shutdown and current limit protection
• PCB Dimensions 85 x 71.60 mm

Schematic

Parts List

Connections

Gerber View

Photos

Video

LM2576 Datasheet

Please follow and like us: