# US 10,873,327 B2 · Hot swap controller with multiple current limits > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,873,327 B2 - Document ID: US10873327B2 - Status: Granted - Kind: B2 - Application number: 16/738,922 - Filed: 2020-01-09 - Published: 2020-05-07 - Granted: 2020-12-22 - Earliest claimed: 2017-09-29 - Assignees: Texas Instruments Incorporated - Applicants: Texas Instruments Incorporated - Inventors: Artem Andreevich Rogachev - Web page: https://patentgrep.com/patent/US10873327B2 ## CPC - H03K 17/08122: {in field-effect transistor switches} - G06F 13/4081: {Live connection to bus, e.g. hot-plugging (current or voltage limitation during live insertion H02H9/004)} - H02H 9/004: {in connection with live-insertion of plug-in units (involving communication with a central processing unit G06F13/40)} - H03K 5/19: Monitoring patterns of pulse trains (indicating amplitude G01R19/00; indicating frequency G01R23/00; measuring characteristics of individual pulses G01R29/02) - H03K 17/122: {in field-effect transistor switches} - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) ## Abstract A hot swap controller circuit includes a comparator and current control circuitry. The comparator is configured to compare voltage across a power transistor controlled by the hot swap controller circuit to a predetermined threshold voltage. The current control circuitry is coupled to the comparator. The current control circuitry is configured to limit current through the power transistor to no higher than a predetermined high current based on the voltage across the transistor being less than the predetermined threshold voltage. The current control circuitry is also configured to limit the current through the transistor to be no higher than a predetermined low current based on the voltage across the transistor being greater than the predetermined threshold voltage. The predetermined high current is greater than the predetermined low current. ## Claims ### Claim 1 Controller circuitry comprising: (a) a power terminal adapted to be coupled to a power supply lead, a sense terminal adapted to be coupled to a first terminal of a power transistor, a gate terminal adapted to be coupled to a gate of the power transistor, and a control terminal adapted to be coupled to a second terminal of the power transistor through a control resistor; (b) a voltage divider resistor coupled between the control terminal and the power terminal; (c) comparator circuitry having a first input coupled to the control terminal, having a second input coupled to a reference voltage output, and having a comparator output; (d) selector circuitry having a high voltage input, having a low voltage input, having a control input coupled to the comparator output, and a selector output; and (e) an amplifier having a first input coupled to the selector output, having a second input coupled to the sense terminal, and having an amplifier output coupled to the gate terminal. ### Claim 2 (depends on 1) The controller circuitry of claim 1 in which the comparator first input is an inverting input. ### Claim 3 (depends on 1) The controller circuitry of claim 1 in which the comparator second input is a non-inverting input. ### Claim 4 (depends on 1) The controller circuitry of claim 1 in which the reference voltage output provides 1.5 volts. ### Claim 5 (depends on 1) The controller circuitry of claim 1 in which the high voltage input receives 25 millivolts. ### Claim 6 (depends on 1) The controller circuitry of claim 1 in which the low voltage input receives 3 millivolts. ### Claim 7 (depends on 1) The controller circuitry of claim 1 in which the amplifier first input is a non-inverting input. ### Claim 8 (depends on 1) The controller circuitry of claim 1 in which the amplifier second input is an inverting input. ### Claim 9 An electronic device comprising: (a) a power input; (b) a power output; (c) a power transistor having a gate and having power terminals coupled between the power input and the power output; (d) a sense resistor coupled between the power input and the power transistor; (e) a control resistor having a lead coupled to the power output; and (f) controller circuitry including: (i) a power terminal to the power input, a sense terminal coupled to a first terminal of the power transistor, a gate terminal coupled to the gate of the power transistor, and a control terminal coupled to the second terminal of the power transistor through the control resistor; (ii) a voltage divider resistor coupled between the control terminal and the power terminal; (iii) comparator circuitry having a first input coupled to the control terminal, having a second input coupled to a reference voltage output, and having a comparator output; (iv) selector circuitry having a high voltage input, having a low voltage input, having a control input coupled to the comparator output, and having a selector output; and (v) an amplifier having a first input coupled to the selector output, having a second input coupled to the sense terminal, and having an amplifier output coupled to the gate terminal. ### Claim 10 (depends on 9) The electronic device of claim 9 in which the comparator first input is an inverting input. ### Claim 11 (depends on 9) The electronic device of claim 9 in which the comparator second input is a non-inverting input. ### Claim 12 (depends on 9) The electronic device of claim 9 in which the reference voltage output provides 1.5 volts. ### Claim 13 (depends on 9) The electronic device of claim 9 in which the high voltage input receives 25 millivolts. ### Claim 14 (depends on 9) The electronic device of claim 9 in which the low voltage input receives 3 millivolts. ### Claim 15 (depends on 9) The electronic device of claim 9 in which the amplifier first input is a non-inverting input. ### Claim 16 (depends on 9) The electronic device of claim 9 in which the amplifier second input is an inverting input. ### Claim 17 (depends on 9) The electronic device of claim 9 in which the power input receives minus 48 volts.