Description

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.See more TI Precision Designs"