US Patent No. 10,368,412

LED DRIVER


Patent No. 10,368,412
Issue Date July 30, 2019
Title Led Driver
Inventorship John Peter Fenske, Richardson, TX (US)
Muhammad Roshanali Rajabali, Plano, TX (US)
Jeffrey Scott Farris, Flower Mound, TX (US)
Assignee TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US)

Claim of US Patent No. 10,368,412

1. A circuit, comprising:a switch control circuit having a switch control output, a switch control input and a loop control input, the switch control output adapted to be coupled to a control node of a first switch in parallel with a light emitting diode (LED), the loop control input adapted to be coupled to an output node of the first switch, and the switch control circuit configured to: responsive to a signal at the switch control input, generate a first control signal at the switch control output based on whether a current through the first switch is above a threshold;
a switch driver having a driver output and a driver input, the driver output adapted to be coupled to a control node of a second switch in series with an inductor and the first switch, the driver input adapted to be coupled to the output node of the first switch, and the switch driver configured to generate a second control signal at the driver output based on whether the current through the first switch is above the threshold; and
a comparator having a comparator output and first and second comparator inputs, the comparator output adapted to be coupled to the switch control input, the first comparator input adapted to be coupled to a photosensitive device, the second comparator input adapted to be coupled to a reference node, and the comparator configured to generate a signal at the comparator output based on a magnitude of a signal at the first comparator input relative to a magnitude of a signal at the second comparator input, the signal at the first comparator input being indicative of light detected by the photosensitive device.