LM2577 12V to 16V DC/DC Converter

The circuit is a boost step-up regulator based around an LM2577-ADJ voltage regulator chip and a few other discrete components. Resistors R1 and R2 set the regulated output voltage.

A switch inside the voltage regulator closes between pins 4 and 3, causing current to flow through the inductor to ground. When the switch is released a few microseconds later, a back-EMF ‘kick’ is produced by the inductor, resulting in a positive pulse with respect to the input voltage. This pulse charges the output capacitor via the schottky diode, which tends towards an equilibrium voltage.
The switch continues to oscillate, the diode preventing the switch from shorting the output capacitor during the ‘on’ phase. The output voltage is monitored via the voltage divider R1/R2, causing the duty cycle of the switch oscillator to be continuously regulated in order to maintain a constant output voltage under varying loads.
Source: http://www.mcrent.com/workbench/dcdc1216/

5V to 12V DC LM2577 Converter step up Voltage Regulator

This is Circuit DC to DC Converter Step up Voltage Regulator From 5V To 12V 1A Regulated Output.

LM2577 (3A)
DC to DC step up voltage regulator.
Wide input voltage 3.5Vdc to 40Vdc.
Component list
- 2.2k 1/4W resistor
- 0.1uF capacitor
- 0.33uF capacitor
- 680uF 50V electrolytic capacitor
- 1N5822 high speed schottky diode (3A)
- wire coil inductor, 100uH
- “for LM2577-adj IC” 20k multi-turn variable resistor, set to ratio to R2=2k, R1=18k for voltage output of 12Vdc before soldering
Part number:
- LM2577-12 (12Vdc output)
- LM2577-15 (15Vdc output)
- LM2577-ADJ (1.23Vdc to 37Vdc output)

LM2577 and LM2575 Switching Regulators

Switching regu­lators are available is different circuit configurations in­cluding the flyback, feed-forward, push-pull, and non-iso­lated single-ended or single-polarity types. Also, the switching regulators can operate in any of three modes – step-down, step-up, or polarity inverting.
rovide the active functions for step-down (back) switching regulator, capable of driving a1A 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. LM 2575 series offers a high-efficiency replacement for popular 3-terminal linear regulators. It substantially reduces the size of the heat sink, and in many cases no heat sink is required. Fixed output voltage version is illustrated in figure.

The National Semiconductor LM 1577/LM 2577 are monolithic ICs that provide all of the power and control functions for step-up (boost), fly back, and forward converter switching regulators. The device is available in three different output voltage versions: 12 V, 15 V and adjustable.

Read more: http://www.circuitstoday.com/switching-regulators-using-lm-2575-and-lm-2577
Under Creative Commons License: Attribution

Circuit Switching Regulators Using LM2575 and LM2577

Switching regu­lators are available is different circuit configurations in­cluding the flyback, feed-forward, push-pull, and non-iso­lated single-ended or single-polarity types. Also, the switching regulators can operate in any of three modes – step-down, step-up, or polarity inverting.
rovide the active functions for step-down (back) switching regulator, capable of driving a1A 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. LM 2575 series offers a high-efficiency replacement for popular 3-terminal linear regulators. It substantially reduces the size of the heat sink, and in many cases no heat sink is required. Fixed output voltage version is illustrated in figure.

The National Semiconductor LM 1577/LM 2577 are monolithic ICs that provide all of the power and control functions for step-up (boost), fly back, and forward converter switching regulators. The device is available in three different output voltage versions: 12 V, 15 V and adjustable.

Read more: http://www.circuitstoday.com/switching-regulators-using-lm-2575-and-lm-2577
Under Creative Commons License: Attribution