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

  • Rajkumar Sharma
  • 984
    Views
  • easy
  • Tested

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.

Note: The board works with DC input and due to the onboard rectifier the input polarity is not a problem. This project can also work with AC input, use appropriate filter capacitor for AC input needed, CX capacitor provision helps you to use THT capacitor at input DC line.

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

NOQNTY.REFDESCMANUFACTURERSUPPLIERSUPPLIER PART NO
11CN12 PIN SCREW TERMENAL 5.08MM PITCHWIEDMULLERDIGIKEY281-2888-ND
21CN22 PIN SCREW TERMENAL 5.08MM PITCHWIEDMULLERDIGIKEY281-2888-ND
31C11uF/100V SMD SIZE 1206MURATA/YAGEODIGIKEY
43C2,C5,C8100uF/63V SMD NICHICONDIGIKEY493-6185-1-ND
52C32200uF/63V THT NICHICONDIGIKEY493-1360-ND
65R1,J1,C4,C6,C7DNP
74D1,D2,D3,D41N5408ON SEMIDIGIKEY1N5408FSTR-ND
81D5RED LED SMD SIZE 0805OSRAMDIGIKEY475-1415-1-ND
91D6MBRS360ON SEMIDIGIKEYMBRS360T3GOSCT-ND
101L1150uH/5A 30MM DIABOURNSMOUSER652-2200LL-151-H-RC
111L220uH OR 12uH/4.5A 12MMX12MMBOURNSDIGIKEYSRR1260-120MTR-ND
121P150K POT 16MMBOURNSDIGIKEYPDB181-K415K-503B-ND
131R24.7K 5% SMD 2512 OR 1210MURATA/YAGEO
141R31.21K 1% SMD SIZE0805MURATA/YAGEO
151U1LM2576HVT-ADJ TO220TEXASDIGIKEYLM2576HVT-ADJ/NOPB-ND

Connections



Gerber View

Photos

Video

LM2576 Datasheet

lm2576

PCB

Subscribe
Notify of
guest
0 Comments
Inline Feedbacks
View all comments

RELATED PROJECTS

X
ADP3450 Oscilloscope Giveaway

By continuing to use the site, you agree to the use of cookies. more info

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.

Close