A buck converter uses flying capacitors and cross coupling. The flying capacitors reduce the voltage stress across the inductors and the devices, and may provide high efficiency at very low duty cycle ratios. In addition to the high efficiency performance, the converters may provide a significant reduction in area, since smaller inductors can be used compared to typical buck converters. An example of realization shows up to 90% efficiency at 0.5V output and 10 A load from a 3.6V input with small flying capacitors, compared to what is typically used in a switched capacitor converter.

A buck converter uses flying capacitors and cross coupling. The flying capacitors reduce the voltage stress across the inductors and the devices, and may provide high efficiency at very low duty cycle ratios. In addition to the high efficiency performance, the converters may provide a significant reduction in area, since smaller inductors can be used compared to typical buck converters. An example of realization shows up to 90% efficiency at 0.5V output and 10 A load from a 3.6V input with small flying capacitors, compared to what is typically used in a switched capacitor converter.

The disclosed technology can be used to convert direct-current voltage and current from an input to a different or the same voltage and current at an output. One example direct-current to direct-current (DC-DC) power converter includes a first switch connected between a source voltage and a first side of an inductor, a second switch connected between the first side of the inductor and a ground, a third switch connected between a second side of the inductor and the ground, and a fourth switch connected between the second side of the inductor and a capacitor. The power converter may further include a comparator configured to compare an output voltage at the capacitor to a threshold voltage and based on the result of the comparison selectively activate or deactivate the first, second, third, and fourth switches in a power cycle.

The disclosed technology can be used to convert direct-current voltage and current from an input to a different or the same voltage and current at an output. One example direct-current to direct-current (DC-DC) power converter includes a first switch connected between a source voltage and a first side of an inductor, a second switch connected between the first side of the inductor and a ground, a third switch connected between a second side of the inductor and the ground, and a fourth switch connected between the second side of the inductor and a capacitor. The power converter may further include a comparator configured to compare an output voltage at the capacitor to a threshold voltage and based on the result of the comparison selectively activate or deactivate the first, second, third, and fourth switches in a power cycle.

Present invention is an apparatus and method for power conversion charge pumps that uses cross-coupling capacitors. High efficiency power converter charge pump for both divide by 3 (), divide by 3/2 () are explicitly discussed. The power conversion charge pumps utilizing cross coupled capacitors may provide up to 40% reduction in a number of switches required for a charge pump implementation, thus reducing design area cost while also resulting in high-efficiency performance.

Present invention is an apparatus and method for power conversion charge pumps that uses cross-coupling capacitors. High efficiency power converter charge pump for both divide by 3 (), divide by 3/2 () are explicitly discussed. The power conversion charge pumps utilizing cross coupled capacitors may provide up to 40% reduction in a number of switches required for a charge pump implementation, thus reducing design area cost while also resulting in high-efficiency performance.

A method of converting a positive voltage to a negative voltage includes applying an input signal having intermittent high- (e.g., positive-) and low (e.g., zero or ground) levels to a capacitor network having two or more capacitors; configuring the network into a serial configuration, in which the capacitors are connected to each other in series; charging the capacitors connected in series with the input signal during a pre-charge period, during which the input signal level is high; subsequently, during a pump period, during which the input signal level is low, configuring the network into a parallel configuration, in which the capacitors are connected to each other in parallel; and discharging the capacitors connected in parallel to an output. A negative charge pump includes a network of two or more capacitors, and switches and adapted to switch the capacitor network between a serial configuration, in which the capacitors are connected to each other in series, and a parallel configuration, in which the capacitors are connected to each other in parallel. The negative charge pump has an input adapted to receive an input signal having intermittent high- and low levels, and an output. The switches are adapted to switch the capacitor network into the serial configuration when the input signal is high and switch the switch the capacitor network into the parallel configuration when the input signal is low (e.g., zero or ground level).

The disclosed technology can be used to convert direct-current voltage and current from an input to a different or the same voltage and current at an output. One example direct-current to direct-current (DC-DC) power converter includes a first switch connected between a source voltage and a first side of an inductor, a second switch connected between the first side of the inductor and a ground, a third switch connected between a second side of the inductor and the ground, and a fourth switch connected between the second side of the inductor and a capacitor. The power converter may further include a comparator configured to compare an output voltage at the capacitor to a threshold voltage and based on the result of the comparison selectively activate or deactivate the first, second, third, and fourth switches in a power cycle.

The disclosed technology can be used to convert direct-current voltage and current from an input to a different or the same voltage and current at an output. One example direct-current to direct-current (DC-DC) power converter includes a first switch connected between a source voltage and a first side of an inductor, a second switch connected between the first side of the inductor and a ground, a third switch connected between a second side of the inductor and the ground, and a fourth switch connected between the second side of the inductor and a capacitor. The power converter may further include a comparator configured to compare an output voltage at the capacitor to a threshold voltage and based on the result of the comparison selectively activate or deactivate the first, second, third, and fourth switches in a power cycle.

A charge pump system including charge pump circuitry, a charge pump controller, and current limit circuitry. The charge pump circuitry has an input coupled to a supply input node and has an output for developing a drive voltage. The charge pump controller controls the charge pump circuitry to increase the drive voltage above a supply voltage provided to the supply input node. The current limit circuitry limits current through the charge pump circuitry to a limited current level that is less than a maximum current level during a current limit mode to reduce current spikes at the nodes of the charge pump system that may generate EMI. A current mirror may be used as the current limit circuitry to directly limit current through switches of the charge pump circuitry. The timing of the charge pump switches may also be modified such as inserting strategic delays to reduce the current spikes.