# US 2018/0322934 A1 · Voltage generator and flash memory thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0322934 A1 - Document ID: US20180322934A1 - Status: Published application - Kind: A1 - Application number: 15/668,683 - Filed: 2017-08-03 - Published: 2018-11-08 - Earliest claimed: 2017-05-04 - Assignees: Winbond Electronics Corp. - Applicants: Winbond Electronics Corp. - Inventors: Shih-Ming Tsai - Web page: https://patentgrep.com/patent/US20180322934A1 ## CPC - G11C 16/3436: {Arrangements for verifying correct programming or erasure} - G11C 5/147: {Voltage reference generators, voltage or current regulators; Internally lowered supply levels; Compensation for voltage drops (G11C5/141 takes precedence)} - G11C 8/08: Word line control circuits, e.g. drivers, boosters, pull-up circuits, pull-down circuits, precharging circuits, for word lines - G11C 16/08: Address circuits; Decoders; Word-line control circuits - G11C 16/30: Power supply circuits - G11C 29/021: {in voltage or current generators} - G11C 29/028: {with adaption or trimming of parameters} - H02M 3/07: using capacitors charged and discharged alternately by semiconductor devices with control electrode {, e.g. charge pumps} - G11C: STATIC STORES (semiconductor memory devices H10B) - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) ## Abstract A voltage generator and a flash memory thereof are provided. The voltage generator is used to provide a work reference voltage having a plurality of reference levels to a word line decoder circuit and includes a plurality of voltage trimming circuits. The voltage trimming circuits are connected in series between the work reference voltage and a ground voltage and respectively receive a trimming code, wherein the voltage levels of the work reference voltages are controlled by the trimming codes received by the voltage trimming circuits to select one of the reference levels. ## Claims ### Claim 1 A voltage generator adapted to provide a work reference voltage having a plurality of reference levels to a word line decoder circuit, the voltage generator comprising: a plurality of voltage trimming circuits connected in series between the work reference voltage and a ground voltage and respectively receiving a trimming code, wherein a voltage level of the work reference voltage is controlled by the trimming codes received by the voltage trimming circuits to select one of the reference levels; a charge pump receiving a gain voltage to provide the work reference voltage; an impedance circuit coupled in series between the work reference voltage and the voltage trimming circuits; a voltage divider coupled in series between the voltage trimming circuits and the ground voltage to provide a feedback voltage different from the work reference voltage; and a differential amplifier receiving the feedback voltage different from the work reference voltage and an operation reference voltage to provide the gain voltage. ### Claim 2 (depends on 1) The voltage generator according to claim 1, wherein each of the voltage trimming circuits comprises an input end, a control end, and an output end, wherein the input end is coupled to the work reference voltage or the output end of a previous one of the voltage trimming circuit, the control end receives the corresponding trimming code, and the output end is coupled to the input end of a following one of the voltage trimming circuit or the ground voltage. ### Claim 3 (depends on 2) The voltage generator according to claim 2, wherein each of the voltage trimming circuits comprises: a resistor series coupled to the output end and comprising a plurality of resistors connected in series, wherein each of the resistors comprises a first end and a second end; a plurality of switches each comprising a first end coupled to the input end, a second end coupled to the second end of the corresponding resistor, and a control end; a logic circuit receiving the corresponding trimming code to provide a plurality of switch signals; and a plurality of level shifters respectively coupled between the logic circuit and the control ends of the switches and controlling the switches according to the switch signals. ### Claim 4 (depends on 3) The voltage generator according to claim 3, wherein the number of the switches of the voltage trimming circuits is 2n, wherein n is larger than or equal to 1. ### Claim 5 (depends on 1) The voltage generator according to claim 1, wherein the voltage trimming circuits respectively receive the trimming codes having different bit numbers. ### Claim 6 (depends on 5) The voltage generator according to claim 5, wherein the trimming code received by the voltage trimming circuit that is closer to the work reference voltage has a larger bit number while the trimming code received by the voltage trimming circuit that is closer to the ground voltage has a smaller bit number. ### Claim 7 (depends on 1) The voltage generator according to claim 1, wherein the voltage trimming circuits receive the trimming codes having the same bit number. ### Claim 8 (canceled) ### Claim 9 (canceled) ### Claim 10 (depends on 1) A flash memory, comprising: a memory array; a word line decoder circuit receiving a work reference voltage and a row address to provide a row selection voltage to the memory array; and the voltage generator of claim 1 coupled to the word line decoder circuit to provide the work reference voltage and receiving a voltage adjustment signal to adjust a voltage level of the work reference voltage, wherein the voltage adjustment signal comprises a plurality of trimming codes.