Patent ID: 6885179

Claim:
A bandgap reference circuit comprising: an operational amplifier ( 62 , 82 ) having a positive input end, a negative input end, and an output end; a first transistor (M 1 , M 1 ) having a source connected to a first voltage and a drain connected to the positive input end and separately to a first node (n 1 ) through a first resistor (R 3 ); a second transistor (M 2 , M 2 ) having a source connected to the first voltage and a drain connected to a second node (n 2 ) through a second resistor (R 4 ), the second node (n 2 ) being connected to the negative input end; a gate of the second transistor (M 2 , M 2 ) connected to a gate of the first transistor (M 1 , M 1 ) and the output of the operational amplifier ( 62 , 82 ); a third resistor (R 1 a ) and a fourth resistor (R 1 b ) connected in series at the first node (n 1 ), the third and fourth resistors (R 1 a , R 1 b ) connected in parallel with a first diode (Q 1 , Q 1 ) between a first current source (I 1 ) and a second voltage; and a fifth resistor (R 2 a ) and a sixth resistor (R 2 b ) connected in series at the second node (n 2 ), the fifth and sixth resistors (R 2 a , R 2 b ) connected in parallel with a second diode (Q 2 , Q 2 ) between a second current source (I 2 ) and the second voltage.