CV Amplifier
The CV amplifier controls the output of the power module when the module is operating in constant voltage mode. The CV amplifier consists of two stages: an error amplifier stage and a voltage monitor stage. The calibrated CVPROG* signal from the CV DAC pulls current out of the negative input of the error amplifier at a rate determined by the DAC’s programmed value. The error amplifier in turn, controls the output of the module.
The output of the module is monitored by the voltage monitor stage. It reduces the module’s output voltage so that the 0 to
When the current pulled out of the error amplifier input by the CV DAC exceeds the current fed into the input by the voltage monitor, the error amplifier turns on, which turns the output of the module on. When the current pulled out of the error amplifier input by the CV DAC is less than the current fed into the input by the voltage monitor, the error amplifier turns off, which turns off the output of the module. When the current pulled out of the error amplifier input by the CV DAC is equal to the current fed into the input by the voltage monitor, the net current into the error amplifier is zero. At this point, there is no change on the output voltage of the power module because the output voltage equals the programmed voltage value.
CC Amplifier
The CC amplifier controls the output of the power module when the module is operating in constant current mode. The CC amplifier also consists of two stages: an error amplifier stage, and a current monitor stage. The calibrated CCPROG* signal from the CC DAC pulls current out of the negative input of the error amplifier at a rate determined by the DAC’s programmed value. The error amplifier in turn, controls the output of the module.
The current monitor stage monitors the current at the output of the module by sensing the voltage drop across current monitor resistor (RM). The current monitor amplifies this voltage (which is typically in the range of 0 to 50mV) so that the 0 to
When the current pulled out of the error amplifier input by the CC DAC exceeds the current fed into the input by the current monitor, the error amplifier turns on, which turns on the output of the module. When the current pulled out of the error amplifier input by the CC DAC is less than the current fed into the input by the current monitor, the error amplifier turns off, which turns off the output of the module. When the current pulled out of the error amplifier input by the CC DAC is equal to the current fed into the input by the current monitor, the net current into the error amplifier is zero. At this point, there is no change on the output current of the power module because the output current equals the programmed current value.
OR Gates
The outputs of the CV and CC amplifiers are "or"ed through two diodes, producing a single