Топологии импульсных преобразователей презентация

Switching Power Supplies A to Z Basic Switcher Architectures Thanks to John Bittner

Voltage Mode Buck Regulator Basic Architecture

Feedback, Error Amplifier, and Compensation – Two Types

Voltage Mode Buck Regulator Loop Gain Modulator and Power Stage gain: Feedback, Error Amplifier, and Compensation gain (Gm-type Error Amp): Regulator loop gain, H(s):

Voltage-Mode Buck Regulator Frequency Response

Current Mode Buck Regulator Basic Architecture

Current Mode Buck Regulator Loop Gain Gain of Modulator and Power Stage:

Current Mode Buck Regulator Loop Gain Feedback, Error Amplifier, and Compensation gain (Gm-type Error Amp): Regulator loop gain:

Current-Mode Buck Regulator Frequency Response

Hysteretic Buck Regulator Basic Architecture

Hysteretic Buck Regulator Switching Waveforms

Calculating Hysteretic Regulator Switching Frequency In most cases, switching frequency is determined by output ripple voltage (VOUT) resulting from ESR. Amplitude of VOUT is described by the following two equations: Combining these two equations yields an expression for the switching frequency

Compensating for excessive ESL in output capacitor

Constant On-Time Buck Regulator Basic Architecture

Constant On-time Buck Regulator Switching Waveforms

Calculating Constant 0n-Time Regulator Switching Frequency tON is a constant, so the regulator must adjust tOFF to the value necessary to maintain charge balance in the inductor. This is expressed by the following equation: Solving this equation for 1/T yields an expression for the switching frequency: