US 11,960,311 B2
Linear voltage regulator with isolated supply current
Seth N. Kazarians, Duarte, CA (US); Adam S. Trock, Simi Valley, CA (US); Jalal Elidrissi, Santa Clarita, CA (US); and Fatemeh Delijani, Chatsworth, CA (US)
Assigned to Medtronic MiniMed, Inc., Northridge, CA (US)
Filed by MEDTRONIC MINIMED, INC., Northridge, CA (US)
Filed on Jul. 28, 2020, as Appl. No. 16/940,669.
Prior Publication US 2022/0035392 A1, Feb. 3, 2022
Int. Cl. G05F 1/575 (2006.01); G01R 1/28 (2006.01)
CPC G05F 1/575 (2013.01) [G01R 1/28 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A linear voltage regulator comprising:
an input voltage terminal for a regulator input voltage;
an output voltage terminal for a regulator output voltage;
a series pass field-effect transistor coupled between the input voltage terminal and the output voltage terminal;
a voltage reference source to provide a reference voltage for the linear voltage regulator, the voltage reference source powered by an independent voltage supply that is isolated from the input voltage terminal;
a buffer amplifier comprising a buffer output that is not connected to the output voltage terminal, a positive buffer input coupled to the output voltage terminal, and a negative buffer input coupled to the buffer output, the buffer amplifier powered by the independent voltage supply;
a feedback divider network coupled between the buffer output and a ground terminal, the feedback divider network providing a scaled output voltage at a divider output, wherein the feedback divider network is driven by the buffer output; and
an error amplifier comprising an error output coupled to the transistor, a positive error input coupled to the divider output to receive the scaled output voltage, and a negative error input coupled to the voltage reference source to receive the reference voltage, the error amplifier powered by the independent voltage supply, wherein output of the error amplifier is based on a difference between the reference voltage and the scaled output voltage, and wherein the output of the error amplifier controls impedance of the transistor to adjust a regulator output voltage at the output voltage terminal.