Low Dropout Regulator (LDO)

The aspect of heat transfer which in itself requires an elaborate model is considered here. Taken Into account are the convection and radiation between gas and brick wall, and the conduction from bricks to light diesel oil as a fuel used in this paper. by taking minimum heat loss rate (HLR) as optimization objective. Two boundary conditions of the insulation layers, convective heat transfer and combined convective and radioactive heat transfer, are taken into account. The optimal constructs of the insulation layers with the two boundary conditions are obtained. Improvement of energy efficiency of the most consuming facilities was achieved by improving the use of alternative energy minimization such as reducing the heat loss of hot gases, minimizing the heat radiated through refractory linings of metallurgical furnaces.

This paper presents the design of Low Drop-Out (LDO) voltage regulator has fast transient response and
which exploits a few current else low quiescent current in the operational amplifier PMOS type. We use
band-gap reference for eliminate the temperature dependence. The proposed LDO voltage regulator
implemented in 0.18-µm CMOS technology, we use Folded cascode CMOS amplifiers high performance in
the stability , provide fast transient response which explains a fast settling, the LDO itself should provide in
the output regulator voltages at ∆t equal 2ps with transient variation of the voltage less than 170mV. High
accuracy in the DC response terms, the simulation results show that the accuracy of the output regulator
voltages is 1.54±0.009V, and power consumption of 1.51 mW.

This thesis describes the analysis and design of an ultra low power linear voltage regulator that is targeted for the application in a wireless sensor node. In the introductory chapter, the concepts of wireless sensor nodes, power management and ultra low power design are summarized. The second chapter contains fundamental considerations concerning the design of linear voltage regulators. A small signal model of the control loop is presented and methodologies for stability analysis and performance measures are introduced. The AC characteristics of both NMOS and PMOS pass device transistors are investigated by analytical calculations. A symbolic circuit analysis methodology is introduced that allows the analytical treatment of larger circuits. This methodology is applied to derive analytical models of the power supply rejection of simple CMOS OTAs. In the third chapter, the design of the voltage regulator based on an NMOS pass device is described. A new circuit topology for the control loop is presented that allows the biasing of the pass device for low dropout operation. The proposed topology is analytically investigated concerning stability, power supply rejection and output impedance. Additional circuit blocks like an oscillator, a charge pump and a startup circuit are described. The fourth chapter contains simulation results of the complete system. The functionality is shown by transient simulations and parameter variations are considered. Finally in the last chapter a conclusion of the presented results is given.

The power supply rejection ratio (PSRR) is a crucial specification for the low-dropout regulator (LDO). Many circuit topologies have been proposed to achieve high PSRR for the LDO. To simplify the design flow, most analog circuit designers estimate the PSRR performance based on the small signal model. However, the accuracy of the small signal model for PSRR has not been verified. In this paper, the accuracy of the general small signal model has been analyzed. A new small signal model for PSRR of LDO has been developed and verified. The simulation results shows that the accuracy has been improved significantly while the new model is applied comparing to the general model. The simulation results has been verified using a standard 0.35-µm CMOS process technology.

Super capacitor power bank is a charge storage device composed of normal electrolytic capacitors. As the name suggests it can perform exactly like a charge storage cell. In addition to that it can provide multiple output power options and LDO output for small power applications. The charging and discharging time is one of the crucial factors in the calculation of charge in the device. The charging time of the capacitor is very small and discharging time will be very high. Since we can block the discharging path then the discharging time can be increased to two to three days. The main advantages of the system are less weight, easy to handle and multiple power options. The function of LDO is to provide sustained low drop voltage for low power applications.

In this paper, a high performance adaptive digital low-dropout voltage regulator (ADLDO) is proposed for Internet-of-Things (IoT) applications. In the proposed ADLDO, a fully synthesizable adaptive digital controller is designed. It automatically senses load variations and adaptively controls multi-loop architecture to reduce quiescent current, minimize output voltage ripples and achieve fast transient response. The multi-loop architecture with hill climbing reduces the total bi-directional shift registers length which results in the reduced leakage current in the transistor-switch-array (TSA), and improves the recovery time and output DC voltage accuracy. A dithering technique is introduced to eliminate the limit cycle oscillation (LCO) and improve the performance of the regulator. The dynamic frequency scaling (DFS) mechanism is proposed for reducing controller power consumption in steady state. In order to reduce the offset and output voltage error, a dynamic latch comparator is utilized. When the input supply voltage is varied from 0.5 V to 1 V, the measured output voltage ranges from 0.45 V to 0.95 V with 50 mV dropout voltage. The operating frequency is 10 MHz with fast transient response and quiescent current of 350 ns and 3.7 µA, respectively. The maximum measured power and current efficiencies are 89.7 % and 99.97 %, respectively, with 1.9 mV output voltage ripples. Measured load and line regulations are 2.2 mV/mA and 9.5 mV/V respectively. The proposed circuit is implemented in 28 nm CMOS process and occupies 0.016 mm 2 chip area. INDEX TERMS Adaptive, dithering, digital LDO, dynamic frequency scaling (DFS), fully synthesizable, fast transient, hill climbing, limit cycle oscillation (LCO), low power, multi-loop.

This paper demonstrates the design of a LDO that regulates the power supply voltage 3.3V to a voltage 2.2V, to supply a small current load. This LDO has been designed for minimum current consumption to be the 1st priority. Two different solutions have been proposed, using different topologies of op amps. The first op amp is a folded cascode op amp and the second op amp is a simple two-stage op amp. The second solution was proposed in order to reduce even more the current consumption and the required area.

A new topology for a low dropout regulator with NMOS pass device is presented. The stability is checked by a model derived from symbolic circuit analysis. The startup by use of a pre-charge mechanism and the integrated oscillator and charge pump are described. The regulator is designed for an input voltage range of 1 to 3.6 V, an output voltage of 920 mV and a load current of 1 to 100 μA.
The overall quiescent current is approximately 100 nA.

This paper presents the design of Low Drop-Out (LDO) voltage regulator has fast transient response and
which exploits a few current else low quiescent current in the operational amplifier PMOS type. We use
band-gap reference for eliminate the temperature dependence. The proposed LDO voltage regulator
implemented in 0.18-μm CMOS technology, we use Folded cascode CMOS amplifiers high performance in
the stability , provide fast transient response which explains a fast settling, the LDO itself should provide in
the output regulator voltages at t equal 2ps with transient variation of the voltage less than 170mV. High
accuracy in the DC response terms, the simulation results show that the accuracy of the output regulator
voltages is 1.54±0.009V, and power consumption of 1.51 mW.

Design and implementation of control systems for power supplies require the use of efficient techniques that
provide simple and practical solutions in order to fulfill the performance requirements at an acceptable cost.
Application of manual methods of system identification in determining optimal values of controller settings is
quite time-consuming, expensive and, sometimes, may be impossible to practically carry out. This paper
describes an analytical method for the design of a control system for a fast transient response, low dropout
(LDO) linear regulated power supply on the basis of PID compensation. The controller parameters are
obtained from analytical model of the regulator circuit. Test results showed good dynamic characteristics
with adequate margin of stability. This study shows that PID parameter values sufficiently close to optimum
can easily be obtained from analytical study of the regulator system. The applied method of determining
controller settings greatly reduces design time and cost.

This paper presents the design of Low Drop-Out (LDO) voltage regulator has fast transient response and
which exploits a few current else low quiescent current in the operational amplifier PMOS type. We use
band-gap reference for eliminate the temperature dependence. The proposed LDO voltage regulator
implemented in 0.18-μm CMOS technology, we use Folded cascode CMOS amplifiers high performance in
the stability , provide fast transient response which explains a fast settling, the LDO itself should provide in
the output regulator voltages at t equal 2ps with transient variation of the voltage less than 170mV. High
accuracy in the DC response terms, the simulation results show that the accuracy of the output regulator
voltages is 1.54±0.009V, and power consumption of 1.51 mW.