Voltage doubler
Dickson charge pump
Figure 7. Dickson charge-pump voltage-doubler
The Dickson charge pump, or Dickson multiplier, consists of a cascade of diode/capacitor cells with the bottom plate of each capacitor driven by a clock pulse train. The circuit is a modification of the Cockcroft-Walton multiplier but takes a DC input with the clock trains providing the switching signal instead of the an AC input. The Dickson multiplier normally requires that alternate cells are driven from clock pulses of opposite phase. However, since a voltage doubler, shown in figure 7, requires only one stage of multiplication only one clock signal is required.[12]
The Dickson multiplier is frequently employed in integrated circuits where the supply voltage (from a battery for instance) is lower than that required by the circuitry. It is advantageous in integrated circuit manufacture that all the semiconductor components are of basically the same type. MOSFETs are commonly the standard logic block in many integrated circuits. For this reason the diodes are often replaced by this type of transistor, but wired to function as a diode - an arrangement called a diode-wired MOSFET. Figure 8 shows a Dickson voltage doubler using diode-wired n-channel enhancement type MOSFETs.[13]
Figure 8. Dickson voltage doubler using diode-wired MOSFETs
There are many variations and improvements to the basic Dickson charge pump. Many of these are concerned with reducing the effect of the transistor drain-source voltage. This can be very significant if the input voltage is small, such as a low-voltage battery. With ideal switching elements the output is an integral multiple of the input (two for a doubler) but with a single-cell battery as the input source and MOSFET switches the output will be far less than this value since much of the voltage will be dropped across the transistors. For a circuit using discrete components the Schottky diode would be a better choice of switching element for its extremely low voltage drop in the on state. However, integrated circuit designers prefer to use the easily available MOSFET and compensate for its inadequacies with increased circuit complexity.[14]
As an example, an alkaline battery cell has a nominal voltage of 1.5 V. A voltage doubler using ideal switching elements with zero voltage drop will output double this, namely 3.0 V. However the drain-source voltage drop of a diode-wired MOSFET when it is in the on state must be at least the gate threshold voltage which might typically be 0.9 V.[15] This voltage "doubler" will only succeed in raising the output voltage by about 0.6 V to 2.1 V. If the drop across the final smoothing transistor is also taken into account the circuit may not be able to increase the voltage at all without using multiple stages. A typical Schottky diode, on the other hand, might have an on state voltage of 0.3 V.[16] A doubler using this Schottky diode will result in a voltage of 2.7 V at the output.[17]
http://en.wikipedia.org/wiki/Voltage_doubler
 
128로 펄스 출력을 시켜서 배전압을 얻어보겠습니다.
추가 회로는 다이오드 2개, 캐패시터 2개 입니다.
 
 
 
정전압아답터 5V 전원 공급 외에 배선은 3가닥 뿐입니다.
+5V, GND, 100KHz펄스출력
 
펄스 출력을 연결 하기 전에는 다이오드에 의한 전압 강하에 의해서 5V 보다 조금 낮은 전압이 LED에 걸리게 되고
LED 정격 전압보다 낮으므로 LED는 켜지지 않습니다.
 
 
LED 부하가 없는 상태에서는 10V 가까운 전압을 얻을 수 있지만
 
 
LED가 켜지면 부하로 작용 해서 전압이 낮아집니다.
 
 
#include   
void main(void){
    //CTC Mode
    DDRB=0x20;  // PORTB.5=A
    OCR1A=79;   // 16000000/(1+79)=200KHz
    TCCR1A=0x40; TCCR1B=9; TCCR1C=0x80; //WGM11=0, WGM10=0, WGM13=0, WGM12=1
    while(1){}
} 
200KHz 설정은 CTC모드에서 출력이 토글 되므로 100KHz가 됩니다.