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
                     │
    Vin ──┬─── R1 ───┬─── Op-Amp ───┬─── Iout
          │          │      +       │
          │          │              │
          └─── R2 ───┼─── Op-Amp ───┤
                     │      -       │
                     │              │
                     └─── Rs ───────┘
                     
    Iout = Vin / Rs (for unity gain configuration)
    Conversion Ratio = 1/Rs (A/V)
V
mA/V
Ω
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