Ricoh Company, Ltd.

Toshiya Murota

Masanobu Fukushima

Shohtaroh Sohma

Katsuhisa Furuse

Yasuhiro Ishizaka

Koichi Hagino

Toshihiro Takahashi

Shinichiro Yamada

Naohiko Nishigaki

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.

Switching power supply circuit

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.

Method of finding DC test point of an integrated circuit

Growing community of inventors

Hyogo, Japan

Toshiya Murota