Low side V-I converter reference design, 0-V to 5-V input, 0-mA to 500-mA output


Design files


This verified design provides the theory, component selection, simulation, PCB design, and measurement details for a low-side voltage-to-current (V-I) converter. The circuit delivers a well-regulated current to a floating load which could include actuators, sensors, motors, LEDs and many other applications. The design uses the OPA735 small-signal op amp to control an NPN emitter-follower that sources current to the load. The current is accurately regulated by feeding back the voltage drop across a low-side current-sense resistor to the op amp. The rail-to-rail input/output topology of the OPA735 allows for good accuracy even at low currents because there is very little "dead-zone" in either the input or output stage. The auto-zero zero-drift technology in the OPA735 allows for great DC performance over temperature.

  • Converts Voltage to current: 0 to 5 V, 0 mA to 500 mA    
  • 1 % Error     
  • Single-supply solution with rail-to-rail input op amp
  • Good compliance voltage to the both rails        
  • Design allows for a floating load   
  • Excellent DC performance and temperature drift using zero-drift OPA735 op amp         
This Verified Design Includes:
  • Theory
  • Component Selection
  • TINA-TI Simulation
  • Schematics and PCB Layout
  • Verification and Measured Performance
  • Modification Options
??image.gallery.download_en_US?? View video with transcript Video

A fully assembled board has been developed for testing and performance validation only, and is not available for sale.

Design files & products

Design files

Download ready-to-use system files to speed your design process.

SLAC572.ZIP (510 K)

Detailed schematic diagram for design layout and components

TIDR175.PDF (110 K)

Detailed schematic diagram for design layout and components

TIDR176.PDF (66 K)

Complete listing of design components, reference designators, and manufacturers/part numbers

TIDC138.ZIP (410 K)

Design file that contains information on physical board layer of design PCB


Includes TI products in the design and potential alternatives.

Precision op amps (Vos<1mV)

OPA735Single 0.05uV/degC (max) single-supply CMOS operational amplifier, zero-drift series

Data sheet: PDF

Start development


Technical documentation

= Top documentation selected by TI
No results found. Please clear your search and try again.
View all 1
Type Title Date
* User guide TIPD101 Verified Design Reference Guide Sep. 19, 2013

Related design resources

Design tools & simulation

TINA-TI SPICE-based analog simulation program

Support & training

TI E2E™ forums with technical support from TI engineers

View all forum topics

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​