DC-DC converter with digital current sensing

摘要

A regulated DC-DC switching converter includes a bypass mode in which ends of an output inductor are coupled together. Circuitry determines output capacitor current and load current components of output inductor current during operation of the switching converter, for use in controlling switching operations.

主权项

1. A method of determining output inductor current for a DC-DC switching regulator including a bypass switch coupling ends of an output inductor and an output capacitor, the output inductor having one end coupled to a node between a high side switch and a low side switch coupled in series and another end coupled to the output capacitor and a power load, comprising:
deactivating the bypass and low side switches and activating the high side switch when a bypass mode is disabled; determining a first change in capacitor voltage of the output capacitor over a first time period during which the bypass switch is deactivated; determining a first capacitor current value based on the first change in capacitor voltage, the first time period, and a capacitance of the capacitor; activating the bypass switch and deactivating the low and high side switches when the bypass mode is enabled; determining a second change in capacitor voltage of the output capacitor over a second time period during which the bypass switch is activated; determining a second capacitor current value based on the second change in capacitor voltage, the second time period, and the capacitance of the capacitor; and summing the first capacitor current value and the second capacitor current value to obtain an indication of output inductor current.