US 9,811,105 B2
Reference voltage circuit
Masakazu Sugiura, Chiba (JP); and Tsutomu Tomioka, Chiba (JP)
Assigned to SII SEMICONDUCTOR CORPORATION, Chiba (JP)
Filed by Seiko Instruments Inc., Chiba-shi, Chiba (JP)
Filed on Jan. 14, 2015, as Appl. No. 14/596,923.
Claims priority of application No. 2014-012660 (JP), filed on Jan. 27, 2014.
Prior Publication US 2015/0212536 A1, Jul. 30, 2015
Int. Cl. G05F 3/16 (2006.01); H03K 5/153 (2006.01); G05F 3/24 (2006.01)
CPC G05F 3/16 (2013.01) [G05F 3/24 (2013.01); Y10T 307/549 (2015.04)] 8 Claims
OG exemplary drawing
 
1. A reference voltage circuit comprising:
a first constant current circuit;
a first transistor of a first conductivity type having a source connected to the first constant current circuit, the first transistor having a gate-source voltage substantially equal to a threshold voltage and configured to operate as a first stage source follower;
a second constant current circuit;
a second transistor of a second conductivity type having a gate connected to the source of the first transistor and a source connected to the second constant current circuit, the second transistor having a gate-source voltage substantially equal to a threshold voltage and configured to operate as a second stage source follower; and
an output terminal connected to the source of the second transistor.