# US 11,079,432 B2 · Integrated laser voltage probe pad for measuring DC or low frequency AC electrical parameters with laser based optical probing techniques > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,079,432 B2 - Document ID: US11079432B2 - Status: Granted - Kind: B2 - Application number: 16/279,304 - Filed: 2019-02-19 - Published: 2020-08-20 - Granted: 2021-08-03 - Earliest claimed: 2019-02-19 - Assignees: NXP B.V. - Applicants: Npx B.V. - Inventors: Pieter Gustaaf Nierop; Gerben Boon; Harry Bernardus Antonius Kerver - Web page: https://patentgrep.com/patent/US11079432B2 ## CPC - G01R 15/241: {using electro-optical modulators, e.g. electro-absorption (probes containing electro-optic elements G01R1/071)} - G01R 31/31728: {Optical aspects, e.g. opto-electronics used for testing, optical signal transmission for testing electronic circuits, electro-optic components to be tested in combination with electronic circuits, measuring light emission of digital circuits (probes having electro-optic elements G01R1/071; electro-optic sampling for oscilloscopes G01R13/347; contactless testing of individual semiconductor devices by optical means G01R31/2656)} - G01R 31/2884: {using dedicated test connectors, test elements or test circuits on the IC under test (G01R31/2855 takes precedence)} - G01R 31/31707: {Test strategies (methods for generation of test sequences G01R31/318371)} - G01R 31/318505: {Test of Modular systems, e.g. Wafers, MCM's} - H10P 74/27: {Structural arrangements therefor} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract A semiconductor or integrated circuit block including a sense node and a converter circuit, in which the sense node develops a low frequency electrical parameter that is constant or varies at a frequency below a predetermined frequency level, and in which the converter circuit converts the low frequency electrical parameter into an alternating electrical parameter having a frequency at or above the predetermined frequency level sufficient to modulate a laser beam focused within a laser probe area of the converter circuit. The converter may include a ring oscillator, a switch circuit controlled by a clock enable signal, a capacitor having a charge rate based on the low frequency electrical parameter, etc. The laser probe area has a frequency level based on a level of the low frequency electrical parameter to modulate the reflected laser beam for measurement of the electrical parameter by a laser voltage probe test system. ## Claims ### Claim 1 An integrated circuit block, comprising: a sense node that develops a low frequency electrical parameter when the integrated circuit block is powered, wherein said low frequency electrical parameter is constant or varies at a frequency below a predetermined frequency level; and a converter circuit coupled to said sense node and including a laser probe area, wherein said converter circuit converts said low frequency electrical parameter into an alternating electrical parameter having a frequency at or above said predetermined frequency level sufficient to modulate from a laser beam focused on a point within said laser probe area, a reflected laser beam generated from said laser beam focused on a point within the laser probe area striking said laser probe area are being reflected as the reflected laser beam from said laser probe area. ### Claim 2 (depends on 1) The integrated circuit block of claim 1, wherein: said low frequency electrical parameter comprises an electrical current; and wherein said converter circuit comprises: a current mirror that mirrors said electrical current as a mirrored current; and a ring oscillator coupled in series with said current mirror, wherein said ring oscillator oscillates at a frequency based on a magnitude of said mirrored current. ### Claim 3 (depends on 1) The integrated circuit block of claim 1, wherein: said low frequency electrical parameter comprises an electrical voltage; and wherein said converter circuit comprises: a conversion device that converts said electrical voltage into an electrical current; and a ring oscillator coupled to said conversion device, wherein said ring oscillator oscillates at a frequency based on a magnitude of said electrical voltage. ### Claim 4 (depends on 1) The integrated circuit block of claim 1, wherein: said low frequency electrical parameter comprises an electrical voltage; and wherein said converter circuit comprises: an electronic device incorporating said laser probe area and coupled between a detect node and a supply voltage, wherein said electronic device develops said alternating electrical parameter; a plurality of switches comprising a sense switch and at least one reference switch; wherein said sense switch is coupled between said sense node and said detect node; wherein each of said at least one reference switch is coupled between said detect node and a corresponding one of at least one reference voltage node, wherein each said at least one reference voltage node has a known voltage level; and a switch control circuit that sequentially closes said plurality of switches for each of a plurality of cycles. ### Claim 5 (depends on 4) The integrated circuit block of claim 4, wherein said electronic device comprises a PN junction. ### Claim 6 (depends on 4) The integrated circuit block of claim 4, wherein said at least one reference switch comprises: a first reference switch coupled between said detect node and a first reference voltage node; and a second reference switch coupled between said detect node and a second reference voltage node. ### Claim 7 (depends on 1) The integrated circuit block of claim 1, wherein: said low frequency electrical parameter comprises an electrical current; and wherein said converter circuit comprises: a current mirror that mirrors said electrical current as a mirrored current; a capacitor coupled in series with said current mirror; and a transistor having a current path coupled in parallel with said capacitor and having a control terminal receiving a clock signal. ### Claim 8 (depends on 1) The integrated circuit block of claim 1, wherein: said low frequency electrical parameter comprises an electrical voltage; and wherein said converter circuit comprises: a first transistor having a control input receiving said electrical voltage and having a current path that converts said electrical voltage into an electrical current; a capacitor coupled in series with said current path of said first transistor; and a second transistor having a current path coupled in parallel with said capacitor and having a control terminal receiving a clock signal. ### Claim 9 An integrated circuit block, comprising: a sense node that develops a low frequency electrical parameter when the integrated circuit block is powered, wherein said low frequency electrical parameter is constant or varies at a frequency below a predetermined frequency level; and a converter circuit coupled to said sense node and including a laser probe area, wherein said converter circuit converts said low frequency electrical parameter into an alternating electrical parameter having a frequency at or above said predetermined frequency level sufficient to modulate a laser beam focused on a point within said laser probe area; wherein said low frequency electrical parameter comprises an electrical voltage; and wherein said converter circuit comprises: an electronic device incorporating said laser probe area and coupled between a detect node and a supply voltage, wherein said electronic device develops said alternating electrical parameter; a plurality of switches comprising a sense switch and at least one reference switch; wherein said sense switch is coupled between said sense node and said detect node; wherein each of said at least one reference switch is coupled between said detect node and a corresponding one of at least one reference voltage node, wherein each said at least one reference voltage node has a known voltage level; and a switch control circuit that sequentially closes said plurality of switches for each of a plurality of cycles. ### Claim 10 (depends on 9) The integrated circuit block of claim 9, wherein said electronic device comprises a PN junction. ### Claim 11 (depends on 9) The integrated circuit block of claim 9, wherein said at least one reference switch comprises: a first reference switch coupled between said detect node and a first reference voltage node; and a second reference switch coupled between said detect node and a second reference voltage node. ### Claim 12 An integrated circuit block, comprising: a sense node that develops a low frequency electrical parameter when the integrated circuit block is powered, wherein said low frequency electrical parameter is constant or varies at a frequency below a predetermined frequency level; and a converter circuit coupled to said sense node and including a laser probe area, wherein said converter circuit converts said low frequency electrical parameter into an alternating electrical parameter having a frequency at or above said predetermined frequency level sufficient to modulate a laser beam focused on a point within said laser probe area; wherein said low frequency electrical parameter comprises an electrical current; and wherein said converter circuit comprises: a current mirror that mirrors said electrical current as a mirrored current; a capacitor coupled in series with said current mirror; and a transistor having a current path coupled in parallel with said capacitor and having a control terminal receiving a clock signal. ### Claim 13 An integrated circuit block, comprising: a sense node that develops a low frequency electrical parameter when the integrated circuit block is powered, wherein said low frequency electrical parameter is constant or varies at a frequency below a predetermined frequency level; and a converter circuit coupled to said sense node and including a laser probe area, wherein said converter circuit converts said low frequency electrical parameter into an alternating electrical parameter having a frequency at or above said predetermined frequency level sufficient to modulate a laser beam focused on a point within said laser probe area; wherein said low frequency electrical parameter comprises an electrical voltage; and wherein said converter circuit comprises: a first transistor having a control input receiving said electrical voltage and having a current path that converts said electrical voltage into an electrical current; a capacitor coupled in series with said current path of said first transistor; and a second transistor having a current path coupled in parallel with said capacitor and having a control terminal receiving a clock signal.