Voltage to Current Converter

Calculate voltage to current converter circuits using op-amps. Design voltage controlled current sources for various applications.

Voltage to Current Converter Circuit

                    +Vs
                     โ”‚
    Vin โ”€โ”€โ”ฌโ”€โ”€โ”€ R1 โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€ Op-Amp โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€ Iout
          โ”‚          โ”‚      +       โ”‚
          โ”‚          โ”‚              โ”‚
          โ””โ”€โ”€โ”€ R2 โ”€โ”€โ”€โ”ผโ”€โ”€โ”€ Op-Amp โ”€โ”€โ”€โ”ค
                     โ”‚      -       โ”‚
                     โ”‚              โ”‚
                     โ””โ”€โ”€โ”€ Rs โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”˜
                     
    Iout = Vin / Rs (for unity gain configuration)
    Conversion Ratio = 1/Rs (A/V)
V
mA/V
ฮฉ
V

About Voltage to Current Converters

Voltage to current converters (V-I converters) transform a voltage signal into a proportional current output. They're essential in many analog signal processing applications.

Circuit Types:

  • Howland Current Source: Floating load capability
  • Grounded Load: Simple single op-amp design
  • Differential Input: Better noise immunity
  • Buffered Output: Higher current capability

Applications:

  • 4-20mA current loop transmitters
  • LED driver circuits
  • Sensor excitation
  • Analog signal transmission
  • Test equipment

Design Considerations:

  • Op-amp selection for required performance
  • Compliance voltage limitations
  • Resistor precision and stability
  • Frequency response requirements
  • Load isolation and protection