How to get 5 volts from a higher voltage? Of course by LM7805.
The fact that the chip is the LM7805 linear voltage regulator. This means that all the excess stress she planted on his. That is, when an input voltage of 12 V, she is forced to provide for themselves a voltage drop of 7 volts. Multiply that by at least a current of 100 mA, and already get 0.7 W power dissipation. With a little high currents or the difference between input and output voltage without heat sink is not enough.
Step-down switching regulator – [Link]
Adam introduces the LM21212-1 & LM21215 12-15A High Efficiency, Adjustable Current Synchronous Switching Regulator family, which features:
- Greater than 97% peak efficiency
- 2.95 – 5.5V input voltage range
- Resistor-programmable current (LM21215)
- Synchronous or adjustable frequency up to 1.5 MHz (LM21212-1)
- Start up into pre-biased loads
- Sub-7mΩ integrated FETs
- Output voltage tracking capability
LM21212/15 15A Adjustable Current Buck Regulator – [Link]
This device allows solar cell arrays to be connected to either conventional lead-acid, sealed lead-acid, or lithium storage batteries without fear of overcharging. It allows two different electrical loads to be driven from the batteries at two different charge states to maximise power usage efficiency.
Photovoltaic Solar Battery Regulator and Load Controller – [Link]
ST1S10 is monolithic synchronous step-down regulator able to provide 3A of output current and it is working at 900Khz frequency. The device operates with an input voltage range from 2.5V to 18V and provides an adjustable output range. It can operate either at 900KHz or from an external clock. The high switching frequency allows the use of tiny SMD external components. youritronics.com published an spreadsheet calculator made on OpenOffice Calc and saved as XLS. You have to enter the requested values on brown boxes and you’ll get the result in the yellow boxes. Download the calculator on the link below.
ST1S10 calculator - [Link]
TI instruments announced the TPS82671 step-down regulator that combines all external components on TI’s new MicroSiP(TM) package. This new package simplifies the design of portable applications because it includes all external component on a miniature board. This part is able to provide 600mA of output current. It has a tiny footprint of 6.7mm2 and 90% efficiency at 5.5-MHz operation. It also has a unique PWM frequency dithering feature that reduces noise and improves performance. Check datasheet on the link below.
TPS82671 – 600mA Fully Integrated step-down regulator - [Link]
LM2596 is a step-down (buck) Switching Regulator capable of delivering 3A of current and it is working at 150 KHz switching frequency. Using a few external components you are able to build a powerful power supply. It comes on 3.3V, 5V, 12V, and adjustable output versions.
Switching Power Supply Regulator with LM2596 - [Link]
This ebook has a collection of Switching Regulator Circuits for a variety of input and output voltages. Using this catalog you are able to easily select which type of switching regulator fits better on you needs. There are 12 basic circuit categories: Battery, Boost, Buck, Buck-Boost, Flyback, Forward, High Voltage, Multioutput, Off Line, Preregulator, Switched Capacitor and Telecom.
Switching Regulator Circuit Collection - [Link]
This circuit is a voltage regulator based on LM2576 step down regulator. It is able to provide an output of 12V 3A with an input of 16-40V.
LM2576 Switching Regulator 12V 3A - [Link]
The circuit diagram shown here is of a 10V switching regulator based on the LM5007 from National Semiconductors. The LM5007 is an integrated step down switching regulator which has all necessary systems required for making a cost effective and reliable switching regulator circuit. The IC is available in MSOP-8, LLp-8 packages and has a lot of built in features like thermal shut down, under voltage lock out, duty cycle limiting, current limiting etc.
10V switching regulator using LM5007 – [Link]
Here is the circuit diagram of a 30V/3A adjustable regulator using the LM723 IC from the National Semiconductors. LM723 is an integrated series regulator whose output voltage can be adjusted between 2V and 37V. The IC by itself can deliver an output current of 150mA and the maximum input voltage to the IC is 40V.
30V / 3A adjustable regulator using LM723 - [Link]