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:
Jan. 31, 1989
Filed:
Jan. 04, 1988
Denis F Spicer, Bedford, GB;
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
An apparatus and a method for monitoring the functioning of an integrated circuit in operation using an electron beam directed to a particular node of the circuit which is of interest and measuring the energy of the secondary electrons emitted, in which the energy measurement is made using a filter grid, the bias on which is set by comparing a voltage representing the rate of receipt of secondary electrons past the filter grid with a reference voltage and adjusting the bias in response to the comparison so as to reduce the number of electrons received. A current is produced proportional to the difference between the two voltages and applied to charge a capacitor, the voltage on which is used to set the voltage on the filter grid. The electron beam may be pulsed and the comparison gated in synchronism with the pulsing but delayed relative to it so that the control of the filter grid bias is effected only when the signal due to the secondary electrons emitted in response to the beam pulse is received by the comparator.