LT3092
Production
The LT3092 is a programmable 2-terminal current source. It requires only two resistors to set an output current between 0.5mA and 200mA. A multitude of...
Datasheet
LT3092 on Analog.com
This question is regarding the use of LT3092 as a DAC controlled current source. Before I proceed further, let me state some of my references from the ADI forum and the LT3092 datasheet,
Ref 1- LT3092 Datasheet Applications Information
Ref 2 and Ref 3,
Using LT3092 with a DAC
Circuit-
Now moving to my circuit, I would like to use the LT3092 as a DAC-controlled current source that provides an output current roughly in the range between 2mA and 50mA. I am using the inbuilt DAC of ESP32 S2. It has a full-scale range of 0V to 3.3V. I am scaling it down to the suggested range of 0V to 1V using a feedback resistor network with a 50.8k and 24.2k resistor. After scaling it down, I am supplying this voltage to the SET pin of LT3092. I can accurately control this voltage to vary between 0V and 1V.
The IN pin of the LT3092 is supplied with a 5V supply through a 2.6k resistor (I have also tried other combinations to make sure that the minimum load current of 1mA is reached)
I am taking the OUT pin and connecting it to a 10 Ohm resistor which is connected to the ground. I have also connected a capacitor of 1 microfarad (also tried 30 microfarad) between the IN and OUT pins. I am using the SOT 223 package and have also connected the exposed tab to the OUT pin.
I am unable to get the circuit to work as expected. These are my observations,
1. Irrespective of the resistor connected to the output, the load current is always between 0mA and 5mA. The voltage across the shunt drops according to the value connected to the OUT pin and always yields the same output current.
2. The SET pin voltage supplied by the DAC seems to not at all affect the output voltage and hence the output current. The output voltage seems to be affected instead by the voltage supplied to the IN pin.
My theoretical simulation in LTspice is as follows,

Upon reading the forums, I have added a resistor at the IN pin to satisfy min load current conditions and also a capacitor for stability. Really looking forward to your assistance
Regards,
Chandru
Hi, can anyone help me out here?