Abstract: A buck regulator switching power supply (10) selectively enabling a low side device to effectively recharge a bootstrap capacitor (Cboot) during a high duty cycle of operation. The switching power supply (10) includes a gate driver (12) driving a gate of a high side FET (Q1) responsive to a controller circuit (14). Controller circuit (14) includes a controller (16) responsively controlled by a comparator (18). Comparator (18) senses the charge of the charging side of the bootstrap capacitor (Cboot) as compared to a voltage (Vref). The comparator (18) also responsively generates an output signal on an output line (20) as a function of the voltage at the phased output.

Abstract: A synchronized sampled data system comprising two or more sampled data circuits (10) each sharing a common databus (12) providing instructional words. Each sampled data system has an output (20) synchronized and phase shifted with respect to the other by preloading a unique start word into its respective internal counter (22) via a common control line. After initialization, each counter is clocked in synchronization with the other by a common clock (SCLK), such that the counter's counts remain the predetermined count difference from the other, and respective circuit output (20) maintains the corresponding phase relationship. The present invention finds particular advantages controlling switching power supplies and A to D converters. A desired phase lag can be established with a granularity of 1/M clock cycles. The present invention achieves lower input ripple current, lower in-band conducted emissions and better signal to noise ratio of the whole system.

Abstract: A switch mode power supply (30) having a power-good function (34) which senses whether a switch mode converter (32) is switching. The power-good function determines and indicates that the switch mode power supply is within tolerance when the switch mode converter is switching, i.e., a duty cycle is between 0 and 100%. Conversely, has a duty cycle determined to be 0% or 100%, the power-good function determines and indicates that the power supply is outside tolerance. The power-good function circuitry senses the output directly, (mode A) wherein the switching converter is driven by an integrator consisting of an error amplifier within the feedback loop. The power-good function is simple, accurate, and saves valuable silicon space, especially when implemented in switch mode power supplies that are programmable and have multiple output lines.