# US 2018/0323722 A1 · Secondary controller applied to a secondary side of a power converter and operation method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0323722 A1 - Document ID: US20180323722A1 - Status: Published application - Kind: A1 - Application number: 15/965,996 - Filed: 2018-04-30 - Published: 2018-11-08 - Earliest claimed: 2017-05-05 - Assignees: Leadtrend Technology Corp. - Applicants: Leadtrend Technology Corp. - Inventors: Yao-Tsung Chen; Mao-Shih Li; San-Yi Li; Hung-Ching Lee - Web page: https://patentgrep.com/patent/US20180323722A1 ## CPC - H02M 3/33561: {having more than one ouput with independent control} - H02M 3/33523: {with galvanic isolation between input and output of both the power stage and the feedback loop} - H02M 1/0032: {Control circuits allowing low power mode operation, e.g. in standby mode} - Y02B 70/10: Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes - 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) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A secondary controller applied to a secondary side of a power converter includes a detector and a standby signal generation circuit. The detector is used for detecting a first signal and a second signal of a universal serial bus device, and a frequency of a synchronization signal corresponding to a primary side of the power converter. The standby signal generation circuit is coupled to the detector for delaying a first predetermined time to generate a standby signal to a primary controller of the primary side of the power converter when the detector fails to detect the first signal and the second signal, and the frequency of the synchronization signal is less than a first predetermined frequency, wherein the primary controller enters a standby mode according to the standby signal. ## Claims ### Claim 1 A secondary controller applied to a secondary side of a power converter, comprising: a detector for detecting a first signal and a second signal of a universal serial bus (USB) device and a frequency of a synchronization signal corresponding to a primary side of the power converter; and a standby signal generation circuit coupled to the detector for delaying a first predetermined time to generate a standby signal to a primary controller of the primary side of the power converter when the detector fails to detect the first signal and the second signal, and the frequency of the synchronization signal is less than a first predetermined frequency, wherein the primary controller enters a standby mode according to the standby signal. ### Claim 2 (depends on 1) The secondary controller of claim 1, wherein after the secondary controller generates the standby signal, the secondary controller enters the standby mode, and after the secondary controller enters the standby mode, the secondary controller turns off circuits within the secondary controller other than the detector, the standby signal generation circuit, and a comparator further comprised in the secondary controller. ### Claim 3 (depends on 1) The secondary controller of claim 1, wherein the first signal and the second signal are a differential signal pair. ### Claim 4 (depends on 1) The secondary controller of claim 1, wherein the standby signal is an analog signal, a digital signal, or a mixed-mode signal. ### Claim 5 (depends on 1) The secondary controller of claim 1, further comprising: a comparator for comparing an output voltage of the secondary side of the power converter with a first reference voltage, and comparing the output voltage with a second reference voltage after the detector detects a rising edge of the synchronization signal until the detector detects a falling edge of the synchronization signal. ### Claim 6 (depends on 5) The secondary controller of claim 5, wherein when the output voltage is between the first reference voltage and the second reference voltage, the comparator generates a comparison signal to the standby signal generation circuit, and the standby signal generation circuit generates a turning-on signal to the primary controller according to the comparison signal. ### Claim 7 (depends on 6) The secondary controller of claim 6, wherein after the standby signal generation circuit generates the turning-on signal to the primary controller, a gate control signal generation circuit of the primary controller generates a gate control signal to a power switch of the primary side of the power converter accordingly, and the power switch is turning-on and turning-off according to the gate control signal. ### Claim 8 (depends on 7) The secondary controller of claim 7, wherein after the gate control signal generation circuit generates the gate control signal, if a detector of the primary controller fails to detect a corresponding signal corresponding to the turning-on signal within a second predetermined time, the primary controller leaves the standby mode. ### Claim 9 (depends on 8) The secondary controller of claim 8, wherein after the primary controller enters the standby mode, the primary controller turns off circuits within the primary controller other than the detector and the gate control signal generation circuit of the primary controller. ### Claim 10 (depends on 5) The secondary controller of claim 5, wherein when the output voltage is less than the second reference voltage, the standby signal generation circuit generates a leaving signal to the primary controller after a turning-on signal generated by thereof, and the primary controller leaves the standby mode accordingly, wherein the secondary controller leaves the standby mode as the primary controller leaves the standby mode. ### Claim 11 (depends on 5) The secondary controller of claim 5, wherein when the output voltage is between the first reference voltage and the second reference voltage and the frequency is greater than a second predetermined frequency, the standby signal generation circuit generates a leaving signal to the primary controller after a turning-on signal generated by thereof, and the primary controller leaves the standby mode accordingly, wherein the secondary controller leaves the standby mode as the primary controller leaves the standby mode. ### Claim 12 (depends on 1) The secondary controller of claim 1, wherein when the detector detects the first signal and the second signal, the standby signal generation circuit generates a leaving signal to the primary controller after a turning-on signal generated by thereof, and the primary controller leaves the standby mode accordingly, wherein the secondary controller leaves the standby mode as the primary controller leaves the standby mode. ### Claim 13 An operation method of a secondary controller applied to a secondary side of a power converter, wherein the secondary controller comprises a detector, a standby signal generation circuit, and a comparator, the operation method comprising: the detector detecting a first signal and a second signal of a universal serial bus device and a frequency of a synchronization signal corresponding to a primary side of the power converter; and the standby signal generation circuit delaying a first predetermined time to generate a standby signal to a primary controller of the primary side of the power converter when the detector fails to detect the first signal and the second signal, and the frequency of the synchronization signal is less than a first predetermined frequency, wherein the primary controller enters a standby mode according to the standby signal. ### Claim 14 (depends on 13) The operation method of claim 13, wherein after the secondary controller generates the standby signal, the secondary controller enters the standby mode, and after the secondary controller enters the standby mode, the secondary controller turns off circuits within the secondary controller other than the detector, the standby signal generation circuit, and the comparator. ### Claim 15 (depends on 13) The operation method of claim 13, wherein the first signal and the second signal are a differential signal pair. ### Claim 16 (depends on 13) The operation method of claim 13, further comprising: the comparator comparing an output voltage of the secondary side of the power converter with a first reference voltage, and comparing the output voltage with a second reference voltage after the detector detects a rising edge of the synchronization signal until the detector detects a falling edge of the synchronization signal. ### Claim 17 (depends on 16) The operation method of claim 16, wherein when the output voltage is between the first reference voltage and the second reference voltage, the comparator generates a comparison signal to the standby signal generation circuit, and the standby signal generation circuit generates a turning-on signal to the primary controller according to the comparison signal. ### Claim 18 (depends on 17) The operation method of claim 17, wherein after the standby signal generation circuit generates the turning-on signal to the primary controller, a gate control signal generation circuit of the primary controller generates a gate control signal to a power switch of the primary side of the power converter accordingly, and the power switch is turning-on and turning-off according to the gate control signal. ### Claim 19 (depends on 18) The operation method of claim 18, wherein after the gate control signal generation circuit generates the gate control signal, if a detector of the primary controller fails to detect a corresponding signal corresponding to the turning-on signal within a second predetermined time, the primary controller leaves the standby mode. ### Claim 20 (depends on 19) The operation method of claim 19, wherein after the primary controller enters the standby mode, the primary controller turns off circuits within the primary controller other than the detector and the gate control signal generation circuit of the primary controller. ### Claim 21 (depends on 16) The operation method of claim 16, wherein when the output voltage is less than the second reference voltage, the standby signal generation circuit generates a leaving signal to the primary controller after a turning-on signal generated by thereof, and the primary controller leaves the standby mode accordingly, wherein the secondary controller leaves the standby mode as the primary controller leaves the standby mode. ### Claim 22 (depends on 16) The operation method of claim 16, wherein when the output voltage is between the first reference voltage and the second reference voltage and the frequency is greater than a second predetermined frequency, the standby signal generation circuit generates a leaving signal to the primary controller after a turning-on signal generated by thereof, and the primary controller leaves the standby mode accordingly, wherein the secondary controller leaves the standby mode as the primary controller leaves the standby mode. ### Claim 23 (depends on 13) The operation method of claim 13, wherein when the detector detects the first signal and the second signal, the standby signal generation circuit generates a leaving signal to the primary controller after a turning-on signal generated by thereof, and the primary controller leaves the standby mode accordingly, wherein the secondary controller leaves the standby mode as the primary controller leaves the standby mode.