i am desgning a quad negative voltage control loop for 4 EMLs. Each EML can sink up to 30 mA of current and needs a tunable voltage from -0.5 to -5 (depends on temp, bias etc....). to make a long story short i need 4 tunable negative voltages each sinking up to 30mA of current. There is nothing standard on the market for this (at least i didnt find anything, would be glad to find out i am wrong), so i decided to use a DAC in series with the AD4505-4.
my questions is this:
can i provide a single negative 5 volt bias for the AD4505-4, i.e. V+ at GND and V- at -5 V (supplied by a charge pump).