Patent ID: 6741119
Filing Date: 2004-05-25
Classification: G05F

Abstract:
An apparatus including biasing circuitry for generating and maintaining a substantially constant output bias current notwithstanding variations in circuit fabrication processes, power supply voltage and operating temperature, comprising:first current replication circuitry that receives a reference current having a magnitude Iref and in response thereto generates a bias signal, and a first replica current having a magnitude N*Iref; second current replication circuitry, coupled to said first current replication circuitry, that receives said bias signal and in response thereto generates a branch current having a magnitude Ib, and a second replica current having a magnitude M*Ib; a reference transistor, coupled to said first and second current replication circuitry, that receives said branch current as an input current and conducts said first replica current as an output current; and output transistor circuitry, coupled to said second current replication circuitry, that receives said second replica current and in response thereto generates an output current having a magnitude M*N*Iref.