UC1843: UCx84xCurrent-ModePWM Controllers want to use it in an application as a current-source

Is there a UCx84x Current-Mode PWM Controller-like IC that brings out the error amplifier's non-inverting pin so that the user can supply his own reference to that pin?  I would like to connect a DAC to that pin so that I can use the DAC to adjust the output current when I use the PWM controller in a current source application.  I would sense the current with an instrumentation amplifier and bring the output of the instrumentation amplifier  to the inverting pin of the error amplifier and of course add an RC from the inverting pin to the error amplifier output for compensation.  The DAC voltage would control the voltage across the shunt resistor measuring the current-source output current and thus the DAC would be able to adjust the current source current.