Switching Improves Regulator Efficiency
Switching Improves Regulator Efficiency, further index2. Index2 also
Switching Improves Regulator Efficiency, Index2 also further index2.The linear regulator in Ref.  utilized a highslewrate amplifier with a push– pull output stage to improve transient response while consuming low quiescent current to increase lightload efficiency. This amplifier is capable of providing the Switchedcapacitor regulators can generate output voltages that can be much higher or lower than their input voltages while maintaining their high efficiency by charging capacitors and reconfiguring capacitor connections through switches.StepDownSwitching Regulator Input Voltage OutputVoltage Vin Vsw Gnd StepUp SwitchingRegulator Inverting SwitchingRegulator Input Voltage V VswInput Voltage OutputVoltage Vin VswGnd OutputVoltage in Gnd Figure 2322. Stepdown, stepup, and inverting switching regulators..Courtesy Maxim Integrated Products. 23.6 Synchronous Rectification LowVoltage Power Supplies Synchronous rectifiers can improve switchingpowersupply efficiency, particularly in lowvoltage overall efficiency for this polar architecture. Even though the RF power device is operating at very high efficiency, this efficiency is not “visible” to the power supply because of the IR losses in the linear regulator. Efficiency can be dramatically improved by also including switching structures within the envelope modulator. Two prominent options are powertracking switching (PTS) and envelopetracking switching (ETS). Of these, ETS always provides the best overall efficiency.The output voltage V0 of the switching regulator is a function.of duty cycle and the input voltage V^. Mathematically it On the other hand, low switching frequency improve efficiency and reduce noise but require large filtering components. As a result 10.23 Types of Switching Regulators The term switched mode regulator is used to describe a circuit which takes d.c. input (unregulated) and provides a single d.c. output of the same or opposite polarity, and of a lower or higher voltage.DESIGN IDEAS Switching improves regulator efficiency * = |HEAD. LINE. £ : * * : ***. **— [. ! *— | 18 3 | I 17 4 | ! | V, I 15 6 | | | 14 7 1 | + . – 15 || || | 13 —Ovo o:= 8 I | 1 uF l | | | t—f > TANTALUM I 11 >O _D192 COMPARATOR_AD630 + 15 |> * AL_1_AFTANTALUM h Fig 1This precision rectifier.uses an AD630 balanced modulator/ demodulator as a commutating amplifier. tation Section of an AD630 balanced modulator/demodulator chip to eliminate the need for such diodes.IEEE Power Electron Lett 3(1):24–29, DOI 10.1109/LPEL.2005.845177 Musunuri S, Chapman P (2005) Improvement of lightload efficiency using widthswitching scheme for cmos transistors. IEEE Power Electron Lett 3(3):105–110, DOI 10.1109/LPEL. 2005.859769 Qahouq J, AbdelRahman O, Huang L, Batarseh I (2007) On load adaptive control of voltage regulators for power managed loads: Control schemes to improve converter efficiency and performance. IEEE Trans Power Figure 4.15(a) shows the measured efficiency of a second switching converter with a hysteretic controller.detailed in  in the presence of different inductor values. The same trend is visible. Optimum switching frequency decreases as the inductance increases. Figure 4.15(b) shows the transient response of the converter in the presence of a 50% instantaneous load change for various inductor values. The decoupling capacitors are integrated on die and exhibit negligible ESL.RectifierRegulators. For most of the switching power supply, two specification parameters are the key factors in deciding their market. One of them is efficiency and the other is the quality of power that it draws from the utility –. The efficiency improvement for power electronic applications at low power levels is achieved by replacing the diodes with MOSFETs..This is known as synchronous rectification. On the other hand, the quality can be improved by improving the power factor of Increased powerdissipa tion caused by higher switching losses increases the ambient temperature around theCPU so theCPU temperature also increases. The Vfb pin provides access to the error amplifier so phase lead can be added to improve transient response and increase circuit stability. Capacitor C7 Regulator Efficiency Considerations A common misconception is that the total efficiency of two circuits in series is the product of the efficiencies of each circuit. This is not true.Increased power dissipation caused by higher switching losses increases the ambient temperature around the CPU so the CPU temperature.also increases. VFB pin provides access to the error amplifier so phase lead can be added to improve transient response and increase circuit stability. The added current required to power the CPU supply causes the 5V regulator efficiency to decrease by about 1% but it also regulates the majority of the CPU power at about 94% efficiency.