The TPS2062/TPS2066 devices are dual-channel, 1-A, power-distribution switches that are intended for applications where heavy capacitive loads and short circuits are likely to be encountered. These devices incorporate 70-milliohm, N-channel MOSFET power switches for power-distribution systems that require multiple power switches in a single package. When output load exceeds current-limit threshold or a short is present, the device limits output current to a safe level by switching into a constant-current mode, pulling the overcurrent logic output low. Current limit for each power switch is set at 1.5 A, typically. When continuous heavy overloads and short circuits increase power dissipation in the switch, causing the junction temperatue to rise, a thermal protection circuit shuts off the switch to prevent damage. Recovery from a thermal shutdown is automatic once the device has cooled sufficiently. Internal circuitry ensures that the switch remains off until valid input voltage is present.
While the 1-A continuous current for one switch can provide up to 5 W of power to the switch output, it may still not be enough for some applications. A simple solution is to gang the two power switches in one package by connecting the two output pins together. Mathematically, this can double the power to a load. However, if voltage drops, switch impedances, and/or the4mal distributions are different between the two channels, the currents in the two power switches will be imbalanced. A current imbalance could cause one power path to run away until breakdown or over-heating occurs. This application report shows that the TPS2062/TPS2066 switches can share the current almost equally when the switches are ganged and effectively double the power outage compared to an indivual single switch.