US 12,216,484 B2
Voltage reference circuit
Sechang Oh, Lexington, MA (US); Soheil Golara, San Jose, CA (US); Denis C. Daly, Wellesley, MA (US); Seyedeh Sedigheh Hashemi, Santa Clara, CA (US); and Mansour Keramat, San Jose, CA (US)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Jun. 23, 2023, as Appl. No. 18/340,759.
Prior Publication US 2024/0427361 A1, Dec. 26, 2024
Int. Cl. G06F 1/26 (2006.01); G05F 1/46 (2006.01); G05F 1/56 (2006.01)
CPC G05F 1/468 (2013.01) [G05F 1/56 (2013.01); G06F 1/26 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An apparatus, comprising:
an output circuit configured to generate an output current and a bias signal using a control signal;
a divider circuit configured to generate a feedback voltage and a reference voltage using the output current; and
an asymmetric differential amplifier circuit including a first transistor and a second transistor manufactured according to a particular manufacturing process having a plurality of available threshold voltages, the first transistor having a first threshold voltage of the plurality of threshold voltages and the second transistor having a second, different threshold voltage of the plurality of threshold voltages, wherein the amplifier circuit is configured to generate the control signal using the feedback voltage, the bias signal, and a difference between the first threshold voltage and the second threshold voltage.