The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 27, 1979
Filed:
Jun. 27, 1977
Richard H Morrow, Temple, PA (US);
Grant F Stetzler, Temple, PA (US);
Western Electric Company, Inc., New York, NY (US);
Abstract
In testing transistor devices, measurements of the collector-emitter leakage current of the devices with the base open (i.e., I.sub.CEO) generally require long measuring intervals. This is due to the necessity of charging the Miller Capacitance of the device under test prior to taking the measurement. While the Miller Capacitance is charging, a small base current flows which makes an accurate reading of the I.sub.CEO very difficult. To shorten these measurement times, a voltage is applied to the base of the device to increase the charging rate of the Miller Capacitance. After a predetermined time, the voltage is disconnected thereby opening the base of the transistor device. The I.sub.CEO reading is then taken at the emitter of the device after it has stabilized to an approximate level of I.sub.CEO. As an alternative to the application of a voltage to the base, a feedback circuit is connected between the emitter and the base of the test device to provide an automatically adjusted driving current to the base. This sets the emitter current at a desired level and rapidly charges the Miller Capacitance. If the desired emitter current is set at the level of maximum allowable I.sub.CEO, a go-no go reading of the device can be very rapidly made after the base is open by determining whether the I.sub.CEO is increasing or decreasing from the present level.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile