Use more switches and the capacitor voltage conversion can be achieved more.
Similarly, the voltage conversion in two phases. In the first phase, switch S1 to S3 closed and switch S4 to S8 open. C1 and C2 in parallel, therefore, assume that C1 equals C2, then charged at half the input voltage Dell Latitude 2100 battery Dell Latitude E4300 battery
Cholder output capacitor charging supply current output. As this capacitor discharges, the output voltage until the desired output voltage below the second stage is activated to increase the output voltage to the above value. In the second phase, C1 and C2 in parallel, connected between Vin and Vout. Close switch S4 to S7, and S1 to S3 and S8 to open. Because the voltage drop across the capacitor is not changing, the transition voltage output to 1.5 times the input voltage
Voltage step-up is completed by the following model ︰ by closing S1 to S7 S8 and maintain open access to 1 times the voltage conversion gain.
Pulse frequency modulation (PFM) program
Figure shows a simplified frequency pulse modulation (PFM) regulatory program, which has used a number of gains. Dell Latitude E5400 battery Dell Latitude E5500 battery
Down the output voltage through the pump / SKIP comparator with 1.2V reference voltage for comparison. PUMP / SKIP comparator output voltage is linear in the start, to ensure a soft start function. When the output voltage exceeds the desired limit, the device does not open, will offer very little current consumption. During this idle state, the output capacitor Cholder the output load current. With the continued discharge capacitor and the output voltage until the desired output voltage below the output voltage until the charge pump is activated again to exceed this.
In the light load, PFM regulatory framework of the main advantages is obvious. Usually provided by the power output load capacity. Supply current is very low, only from time to time by the output capacitor charge pump to reload. Dell Latitude E6400 battery Dell Latitude E6500 battery
In short, the charge controller input of the pump in a wide range of high performance can be maintained because the entrance – the current output voltage conversion according to the basic regulation, not more than the voltage input multiplied by the gain of charge pump of the value of the output voltage will result in a lower power converter further, and efficiency will be reduced proportionately.
Converter input ratio in / out allows the ability to change the gain of the input voltage range to finish all the best efficiency. Ideally, the gain should be a change in linear style. In fact, given the number of fixed capacitors and switches, can reach only a limited gain configuration.
In the figure, the input voltage must be adjusted, and was fed to three comparators positive nodes. All nodes connected to compare reverse the output voltage. The input / output voltage ratio, the output of the comparator to provide a word of three with a gain control circuit, the gain control circuit is used to select the smallest gain G, so you get the conversion desired voltage. However, white LED applications, select the correct gain G is not only the voltage input and output. dell inspiron 1150 battery dell inspiron 1300 battery
Card is used to improve blood adaptive charge pump LED drivers, earning up to one and a half times that. Charge pump connected to the input pins VIN, Vout and the output pin is connected. By adjusting the voltage Vout will be stable in the VREG this constant level. For the anode configuration with a total of LEDs, each input LED current can be controlled using the internal power source, the peak current drive by an external resistor (RSET) to define.
This calculation method is correct or not depends on the following prerequisites: that is, value-VLED VOUT must be large enough to make the component chain does not appear to saturate. In fact, for light emitting diodes to provide a constant current source of tension must be the minimum, and this voltage is called the upper limit of the lowest voltage (HYV), its value will change with the resistance RHR change: dell inspiron 1100 battery fpcbp73ap fpcbp95
charge pump must continue to change for the gain multiplier to ensure that the constant current, to decide what are the multiple gain factors, including the voltage drop of light emitting diode, current source of tension and input voltage. So even if the input voltage range is extremely broad, double charge pump can still win the most efficient operations to reduce energy consumption battery.
Summary
Using the method of inductor-capacitor circuit switch and some benefits, an obvious advantage is the elimination of the inductor and the electromagnetic design problems. Switched capacitor converters in general have a relatively low noise and minimal EMI radiation. In addition, the application circuit is very simple, just a little bit of capacitors. Because the case in the absence of inducer, the final height of the CPC is typically higher than the same device switching converters smaller. fujitsu lifebook t4020 battery fpcbp121 fpcbp121ap