Patent ID: 8204388

Claim:
A circuit, comprising: a first substrate; a first photodiode having a cathode and an anode; a second photodiode having a cathode and an anode; a conductor extending from the first photodiode to the second photodiode to thereby electrically couple the anode of the first photodiode to the cathode of the second photodiode, the conductor having first, second and third portions, such that the second portion constitutes a bonding pad that is provided between the first and third portions, the conductor has a length extending in a first direction in which a current flows from the first photodiode to the second photodiode, and the first portion has a first width, the second portion has a second width, and the third portion has a third width, each of the first, second, and third widths extending in a second direction transverse to the length, the first and third widths being less than the second width; an amplifier having an input and an output, the input being electrically coupled to the second portion of the conductor, the amplifier supplying a voltage at the output based on the current; and a second substrate, such that the first and second photodiodes and the conductor, including the bonding pad, are provided on the first substrate and the amplifier is provided on the second substrate.