SLVSFS4A December 2021 – June 2022 TPS92623-Q1
The TPS92623-Q1 device provides two current output paths for each channel. Current flows from the supply through the R(SNSx) resistor into the integrated current regulation circuit and to the LEDs through OUTx pin and RESx pin. The current output on both OUTx pin and RESx pin is independently regulated to achieve total required current output. The summed current of OUTx and RESx is equal to the current through the R(SNSx) resistor in the channel. The OUTx connects to anode of LEDs load in serial directly, however RESx connects to the LEDs through an external resistor to share part of the power dissipation and reduce the thermal accumulation in TPS92623-Q1.
The integrated independent current regulation in TPS92623-Q1 dynamically adjusts the output current on both OUTx and RESx output to maintain the stable summed current for LED. The TPS92623-Q1 always regulates the current output to the RESx pin as much as possible until the RESx current path is saturated, and the rest of required current is regulated out of the OUTx. As a result, the most of the current to LED outputs through the RESx pin when the voltage dropout is large between SUPPLY and LED required total forward voltage. In the opposite case, the most of the current to LED outputs through the OUTx pin when the voltage headroom is relative low between SUPPLY and LED required forward voltage.