Patent ID: 9107245
Filing Date: 2015-08-11
Classification: H05B

Abstract:
1. A current driver circuit, comprising: a digital to analog converter configured to receive a time varying digital value representing a light intensity and convert the digital value to an time varying analog current signal; a current mirror formed by a first transistor, in a first current mirror leg, having a first transistor control input and a second transistor, in a second current mirror leg, having a second transistor control input, the first transistor control input and the second transistor control input connected to form a control node, the current mirror configured to create a current mirror output which is equal to or larger than the analog current signal based on a ratio of the current mirror to thereby created a modified analog current signal; an amplifier having an input and an output, the amplifier configured to: a balancing amplifier having a first input connected to a drain node of the first transistor and a second input connected to a drain node the second transistor, the balancing amplifier configured to process a signal on the drain node of the first transistor and a signal on the drain node of the second transistor to generate a balancing signal that is provided the first leg of the current mirror to balance the drain nodes of the first transistor and second transistor within the current mirror to establish accuracy in the current mirror output; a light source configured to receive the current mirror output, and responsive to the current mirror output generate a light signal, the light signal having an intensity controlled by and proportional to the digital value.