The LT1999 is a high speed precision current sensing amplifier designed to monitor bidirectional current in a wide common model range. The LT1999 is available in three gain options :10V/V, 20V/V and 50V/V. The LT1999 induces current through an external resistance shunt and produces an output voltage, showing the magnitude and direction of the induced current.
Block diagram
The output voltage is the middle between the reference supply voltage and ground, or the reference level can be set using an external voltage. With a bandwidth of 2MHz and common-mode input range of -5V to 80V, the LT1999 is suitable for monitoring H-bridge motor control, switching power supply, electromagnetic current, and battery charging current from full to exhausted.
Test circuit
The LT1999 operates from a separate 5V power supply and draws 1.55mA. Provide an off mode to reduce power consumption. The LT1999 is available as an 8-pin SOP, an 8-pin MSOP(original pin), or an 8-pin option designed for FMEA
