The UC19432 is an adjustable precision analog controller with 100-mA sink capability if the ISET pin is grounded. A resistor between ISET and ground will modify the transconductance while decreasing the maximum current sink. This will add further control in the optocoupler configuration. The trimmed precision reference along with the non-inverting error amplifier inputs are accessible for custom configuration. A sister device, the UC19431 adjustable shunt regulator, has an on-board resistor network providing six preprogrammed voltage levels, as well as exernal programming capability.