Multi Output DC to DC Converter
This is the circuit diagram of DC to DC converter based LM2596, the circuit has a single input supply and multiple voltage outputs. The circuit has an input voltage range of 15V to 40V. It has 5 outputs: 3.3V at 1.5A; +12V and −12V at 50 mA each; and +5V and −5V at 50 mA each. The 3.3V, +5V and −5V outputs are regulated with ±5% accuracy over line and load variations.
Circuit parts list:
- Cin : 220 μF, 50V, Nichicon UPL1H221MPH
- C1: 270 μF, 63V, Nichicon UPL1J271MRH
- C2, C3: 47 μF, 35V, Nichicon UPL1V470MPH
- D1: MBR360,
- D2, D3: 1N459,
- C4, C5: 0.01 μF
- IC1: LM2596-3.3 (SIMPLE SWITCHER® Step-Down Voltage Regulator)
- IC2, IC3: LM78L05, and LM79L05. (3- Terminal Regulators)
- L1: Custom Inductor with three windings (W1, W2 and W3) with the following specs:
- W1: 47 μH; Peak Current: 2.6A, RMS Current ≈ 2.32A
- W2: Number of turns = 3.4 x Number of turns in W1; RMS Current; 113 mA
- W3: Same as W2
The +12V and −12V outputs are regulated with ±20% accuracy. A typical application of this circuit is where the 3.3V output provides the power to the main circuit which is 3.3V logic, the ±5V outputs power the 5V logic and ±12V outputs provide the bias supply of op-amps.
The efficiency of the circuit with full load at all outputs is 75%. The ripple voltage across the 3.3V output is less than 20 mV and that across the ±12V outputs is less than 30 mV. The ripple across the ±5V is less than 10 mV.
Download the application notes fro this DC to DC converter circuit HERE