Patent ID: 8334724

Claim:
A system, comprising: a photodiode having a first terminal and a second terminal; and an open-loop transimpedance amplifier (OLTA) having a supply voltage node, a ground node, a photocurrent input node, and a second node, wherein the photocurrent input node is coupled to the first terminal of the photodiode, the OLTA comprising: a first current mirror that outputs a first current onto the photocurrent input node and that outputs a second current onto the second node; a diode-connected field effect transistor having a drain, a source, and a gate, wherein the drain and gate are coupled to the photocurrent input node; and a second field effect transistor having a drain, a source, and a gate, wherein the second field effect transistor and the diode-connected field effect transistor form a second current mirror, and wherein the drain of the second field effect transistor is coupled to the second node.