Abstract: A switching power supply circuit for generating an output voltage at an output node based on an input voltage at an input node includes a reference voltage generating circuit configured to generate a reference voltage such that during an initial start-up period of the reference voltage a voltage rise rate of the reference voltage within a first predetermined period from a start point of the initial start-up period and a voltage rise rate thereof within a second predetermined period immediately preceding an end point of the initial start-up period are smaller than a voltage rise rate thereof in a period between the first predetermined period and the second predetermined period, a coil disposed between the input output nodes, and a switch circuit configured to switch on and off to control current through the coil in response to comparison between the reference voltage and a voltage proportional to the output voltage.

Abstract: A switching power supply circuit for generating an output voltage at an output node based on an input voltage at an input node includes a reference voltage generating circuit configured to generate a reference voltage such that during an initial start-up period of the reference voltage a voltage rise rate of the reference voltage within a first predetermined period from a start point of the initial start-up period and a voltage rise rate thereof within a second predetermined period immediately preceding an end point of the initial start-up period are smaller than a voltage rise rate thereof in a period between the first predetermined period and the second predetermined period, a coil disposed between the input output nodes, and a switch circuit configured to switch on and off to control current through the coil in response to comparison between the reference voltage and a voltage proportional to the output voltage.

Abstract: A DC test point finding method includes steps of: displaying a list of all input and output terminals of an integrated circuit; inputting selected terminals among the terminals of the list; inputting a selected test pattern file among a number of stored test pattern files, each test pattern file including a plurality of sequentially occurred test vectors and identified by a name of the test pattern file, the test vectors identified by respective vector numbers; inputting a test point finding condition related to a DC test point; finding the DC test point of the circuit among the selected terminals by using the test vectors of the selected test pattern file and the test point finding condition; and inserting test point data of the DC test point into the list so that the resulting list including the test point data is displayed.