MCP4725- voltage and led.


I bought MCP4725 module.

DAC MCP4725 values 0 - 4095; 0 - 5 volts

I want to measure the current- voltage characteristics(from 0V to 5V).

I have connected to circuit INA219 DC sensor.

When i set on MCP4725 4095 in circuit is 5 volts, but when i connect led into circuit, voltage of curcuit maximum is ~3 volt.(3,2V and 15mA)

why is this happening?

In code i am set voltage from 0 to 5v- but in curcuit is from 0 to ~3V…

#include <Wire.h>
#include <Adafruit_MCP4725.h>
#include <Adafruit_INA219.h>

Adafruit_INA219 ina219;
Adafruit_MCP4725 dac;

void setup() {
  dac.setVoltage(4000, true);

void loop() {
  float shuntvoltage = 0;
  float busvoltage = 0;
  float current_mA = 0;
  float loadvoltage = 0;
for (int x=0; x<4095;x++ ){
  dac.setVoltage(x, true);
  busvoltage = ina219.getBusVoltage_V();
  current_mA = ina219.getCurrent_mA();
  int bus=busvoltage*100;
  int current=current_mA*100;


What is the value of your LED current limiting resistor?

I dont have any resistor for led. Normally the diode should burn on this voltage but in this curcuit
but in this circuit nothing happens.