A delta-sigma based DC to DC converter — A design space exploration

Delta-sigma buck converter — A design exploration for GSM Wireless systems

“…In order to see the viability of using a switching regulator to meet the above requirement, the spurious performance of the PWM based buck regulator obtained from [4] is compared.…”

“…An alternative control solution to reduce the clock spurs of the PWM using the noise shaping characteristics of the delta sigma (ΔΣ) modulator is described in [2][3][4][5][6][7][8]. It has been shown that the ΔΣ can replace the PWM controller in Figure 1 and still retain the stability and power efficiency properties of the conventional switching regulator.…”

“…The location and magnitude of these spurs determine the type of filtering that is required. The spurious performance of the PWM and ΔΣ controller presented in our previous work [4] obtained by performing a FFT on the DR node is shown in Figure 2. The spurs have been normalized for both the systems which make their comparison straightforward.…”

“…This study explores the optimal ΔΣ design parameters obtained from [4] in the framework of specifically powering the GSM wireless communication system application, where both high efficiency and excellent spurious performance are desired.…”

“…Section II describes the spectral requirement for the GSM system while section III extends reference [4] to higher order modulators. The ΔΣ based buck controller is examined for spurious performance and power efficiency for varying output voltages (V out ) and over sampling ratios (OSR), and is then compared with the spectral requirement of the GSM system.…”