POWER MANAGEMENT |
DC-DC Converters, Topologies & Control Techniques Basic nonisolated dc/dc converter topologies, waveforms, and operating modes. Derivative nonisolated converters (two-switch buck-boost, SEPIC, Cuk, coupled-inductor buck). Isolated and multi-output converters. Synchronous rectification. Control techniques: single-loop (constant- frequency and variable-frequency voltage-mode control, voltage regulation without error amplifier), multiple-loop [constant-frequency and variable frequency current-mode control, feedforward control (input-voltage feedforward for line-transient rejection and for frequency stabilization, load-current feedforward), Vsquare control]. Control for improving efficiency at light load. Overload protection techniques. |
Converter Modeling and Feedback Loop Design Averaged small-signal and large-signal models (state-space averaging, direct circuit averaging, method of injected/absorbed currents). Transfer-function block models. Control-to-output and input-to-output transfer functions of voltage-mode-controlled and current-mode-controlled converters. The right-half-plane (RHP) zero. Fundamentals of stability analysis. Feedback loop design for phase/gain margin using the K factor. Practical design examples. |
Microprocessor Power Supplies Power supply specifications for microprocessors. Distribution model and multi-tier decoupling. Effect of parasitics on load transient response. Single-phase and multi-phase converter topologies. Controlling multi-phase converters. Load transient limits. Fast load transient with high dc-gain control. Passive and active voltage positioning techniques. Optimal positioning: current-mode, voltage-mode. On-the-fly programming of the output voltage. Current balance vs. temperature balance in multiphase converters. Maintaining high efficiency at light load with constant on-time control and with phase shedding. Overvoltage protection techniques. |
Battery Charging Techniques & Circuits for Notebook Computers NiCad, NiMH, LiIOn, Li-Metal and Li-Polimer batteries and their properties. Charging and charge termination techniques for the different battery chemistries. Off-line, DC/DC and linear battery charger circuits. |
Bandgap References Voltage references derived from the base-emitter voltage of bipolar transistors, and why they are generally known as "Bandgaps." Fundamental ideas related to most circuits, including noise, temperature behavior and trimming, curvature and curvature correction, and sensitivity to component variability. Some basic circuits and the practical issues related to their use in power management. Additional examples which illustrate the use of parasitic bipolar transistors to derive a reference voltage on CMOS circuits. |
Alternative Bandgaps and Applications Applications of Bandgap References to single and double loop Regulators will be examined, including the "Virtual Bandgap" arrangement. Several implementations of the Bandgap circuit principle will be explained for use in biasing, references, and regulators. |
Fundamentals of Switched-Mode Power Supplies for Portable Applications Review of power management requirements of key IC building blocks in current and future portable applications, comparison of on-chip power conversion methods and topologies: Magnetic switching converters vs switched-capacitor converters (charge-pumps) vs linear power converters (LDO) / Efficiency optimization / Trends in fully monolithic integration of switching power converters: on-chip reactive components for switchers: IC-compatible power inductors and low ESR on-chip capacitors, Power MOSFET switches, efficient switch drivers in standard CMOS technologies / Power management subsystems in an SoC environment. |
Control Techniques and their Integrated Circuit Implementation for Switched-Mode Converters in Portable Applications Review of control requirements / Voltage-mode and current-mode circuit techniques for analog controllers / IC architecture and block design details of analog controller for sliding-mode control, one-cycle control and neurofuzzy control/ Integration of PFM or pulse-skipping control for light-load efficiency improvements/ Description of several practical implementations of analog IC controllers / Digital versus analog control of switching power converters / IC architecture and block design details of digital PWM controller / design of A-D converters / Area and power efficient implementation of digital pulse width modulators (DPWM): hybrid and segmented architectures / Quantization and limit-cycle phenomena in digitally controlled switchers. |
Adaptive Power Management Techniques for Portable Applications Adaptive power supplies for RF power amplifiers/ Slow envelope tracking / Fast Envelope Elimination and Restoration (EER) technique / Specifications for EDGE, IS95 and 3GPP-WCDMA modulations / Adaptive voltage and threshold scaling for low-power microprocessor and DSP supply/ Description of several practical implementations of adaptive power management. |
Transistor-Level Off-Line DC-DC Controller Design Typical application and design of a current-mode off-line, switched-mode power supply. Review of the application diagram and general theory of operation. Start-up and bias techniques. The design of critical blocks, including voltage references, oscillators, error amplifiers, protection circuits, and output drive, with emphasis on design tradeoffs and performance in bipolar and CMOS technologies. |
Switched-Capacitor Power Supplies General overview of switched-capacitor (SC) power supplies: topologies and properties. Efficiency analysis, and circuit techniques that may be used to improve the efficiency. How to design and evaluate CMOS switches for SC power supplies. Step by step design of a voltage doubler. Analysis and several practical examples of how to design voltage multipliers. |
Power CMOS and BCD Linear Amplifier Design Output stage, CMOS and all-NMOS size of the power transistors, class AB circuits. Current limit for amplifier and for load protection. Number of the gain stages, compensation and linearity. Input stage, gain boost and slew rate boost. Biasing and temperature protection. Layout, package and wirebonding. |
Circuit Techniques for Integrated Switching Regulators Power switches: static and dynamic power loss, switch sizing, wire bonds and their inductance, parasitic vertical PNP and lateral NPN structures, substrate noise, signal grounding and isolation of the control circuitry. Switch Control: Low and high-side gate drivers, use of the bootstrap capacitors with charge regeneration, transfer of the control signal to the high-side. Low and high-side synchronous rectifiers: comparator design, minimization of delays, elimination of shoot-through currents. Feedback and frequency compensation: continuous and discontinuous operation, current and voltage mode; inductor current sensing with and without external elements; oscillator and PWM circuits; error amplifier. |