Monday, August 17, 2009

Rangkaian +5V Switching regulator

Rangkaian +5V Switching regulator used LM2575-5.0. You can make the stable voltage by using the 3 terminal regulator like LM317. However, because the output electric current and the inputted electric current are the same approximately, the difference between the input electric power (The input voltage x The input electric current) and the output power (The output voltage x The output current) is consumed as the heat with the regulator. Because it is, the efficiency isn’t good. In case of the switching regulator, it inputs only the electric power which is necessary to output from the input by the switching operation. Because it is, there is little electric power to consume with the regulator and it is efficient.

Switching regulator
Skema Rangkaian +5V Switching regulator

DC to DC step down voltage regulator. Wide input voltage 8Vdc to 40Vdc.
  • LM2575-3.3 (3.3Vdc output)
  • LM2575-5.0 (5Vdc output)
  • LM2575-12 (12Vdc output)
  • LM2575-15 (15Vdc output)
  • LM2575-ADJ (1.23Vdc to 37Vdc output)

The switching regulator which introduces in this page is the step down type and is the one to get the output voltage which is lower than the input voltage. As for the regulator which uses this time, the output is 5-V fixation.
The switching regulator of the step up type can be made the voltage which is higher than the input voltage.

Kegunaan IC LM2575

The LM2575 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving a 1A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5V, 12V, 15V, and an adjustable output version.

Requiring a minimum number of external components, these regulators are simple to use and include internal frequency compensation and a fixed-frequency oscillator.

The LM2575 series offers a high-efficiency replacement for popular three-terminal linear regulators. It substantially reduces the size of the heat sink, and in many cases no heat sink is required.

A standard series of inductors optimized for use with the LM2575 are available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies.

Other features include a guaranteed ±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.

Skema Rangkaian Elektronika