# US 5,708,277 A · Optically coupled device with high current protection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,708,277 A - Document ID: US5708277A - Status: Granted - Kind: A - Application number: 08/569,991 - Filed: 1995-12-08 - Granted: 1998-01-13 - Earliest claimed: 1994-12-28 - Assignees: Sharp Kabushiki Kaisha - Inventors: Atsushi Murayama; Masatosi Kotake; Kazuya Uekawa - Web page: https://patentgrep.com/patent/US5708277A ## CPC - H10F 55/25: wherein the radiation-sensitive devices and the electric light source are all semiconductor devices - H10W 72/5445: {being orthogonal to a side surface of the chip, e.g. parallel arrangements} - H10W 72/926: {Multiple bond pads having different sizes} - H10W 90/756: {between a chip and a stacked lead frame, conducting package substrate or heat sink} - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract An optically coupled device is composed of input and output sides. The input side includes a light-emitting element while the output side includes: an element for driving; a light-receiving element for receiving light from the light-emitting element to turn on the element for driving; and a resistance element having a positive or negative temperature-coefficient and connected in series with the light-receiving element. By the above configuration, the optically coupled device by itself is constructed to prevent rush-current from occurring and to the device itself from being excessively heated due to excessive current. ## Claims ### Claim 1 An optically coupled solid-state relay package comprising: input and output sides sealed in a package, said input side comprising: a light-emitting element, and, said output side consisting of: first and second output terminals; an element for driving, said element being connected between said first and second output terminals; a light-receiving element for receiving light from said light-emitting element to turn on said element for driving, said light-receiving element connected directly to said element for driving; and a resistance element having a positive or negative temperature-coefficient, and connected in series with said light-receiving element. ### Claim 2 An optically coupled solid-state relay package comprising: input and output sides sealed in a package, said input side comprising: a light-emitting element, and, said output side comprising: first and second output terminals; an element for driving, said element being connected between said first and second output terminals; a light-receiving element for receiving light from said light-emitting element to turn on said element for driving; a resistance element having a positive or negative temperature-coefficient, and connected in series with said light-receiving element; a capacitor connected in series with said light-receiving element and with said resistance element between said first and second output terminals; and a triggering element connected between said element for driving and a node, the node being a point of connection between said capacitor and said light-receiving element, said triggering element being triggered at a predetermined voltage to ignite said element for driving, wherein said capacitor charges, in use, to the predetermined voltage thereby delaying the triggering of said triggering element. ### Claim 3 (depends on 2) The optically coupled solid-state relay package according to claim 2, wherein said element for driving is a triac. ### Claim 4 An optically coupled solid-state relay package comprising: input and output sides sealed in a package, said input side comprising: a light-emitting element; and a plurality of series-connected diodes connected in parallel with said light-emitting element, and said output side comprising: first and second output terminals; an element for driving, said element being connected to said first and second output terminals; and a light-receiving element which receives light from said light-emitting element and ignite said element for driving, said light-receiving element connected directly to said element for driving. ### Claim 5 (depends on 4) The optically coupled solid-state relay package according to claim 4, wherein said element for driving is a triac, and said light-receiving element is a phototriac. ### Claim 6 (depends on 4) The optically coupled solid-state relay package according to claim 4, wherein said input side further comprises first and second input terminals, said first and second input terminals being connected directly to said light-emitting element and said plurality of series-connected diodes. ### Claim 7 (depends on 6) The optically coupled solid-state relay package according to claim 6, wherein said input side consists of said first and second input terminals, said light-emitting element, and said plurality of series-connected diodes. ### Claim 8 (depends on 4) The optically coupled solid-state relay package according to claim 4, wherein said input and output sides are sealed in a package, and further include respective input and output terminals. ### Claim 9 An optically coupled device comprising: input and output sides, said input side comprising: a light-emitting element, and, said output side comprising: first and second output terminals; a light-receiving element for receiving light from said light-emitting element; a thyristor connected in series with said light-receiving element between said first and second output terminals; and a resistance element connected between said first output terminal and a gate of said thyristor, said resistance element having a negative temperature-coefficient and being for turning on said thyristor. ### Claim 10 (depends on 9) The optically coupled device according to claim 9, wherein said light-receiving element includes a base and an emitter, said thyristor being connected between the base and the emitter. ### Claim 11 (depends on 10) The optically coupled device according to claim 10, wherein said thyristor is connected to the base and to said second output terminal. ### Claim 12 (depends on 9) The optically coupled device according to claim 9, further comprising a sealed package for housing said input and output sides.