Bidirectional Current Sense Amplifier

Linear Technology's LT1999 has a 2MHz bandwidth to monitorcurrents in H-bridge motor controls, switching power supplies, solenoid andbattery chargers. To maintain accuracy, even when monitoring motor and solenoidcurrent, the LT1999 guarantees more than 80 dB of common-mode rejection at 100kHz. This ensures that the LT1999remains insensitive to the large square wave input common-mode voltages presentin these applications.

The LT1999 features abuffered output with three fixed-gain options for 10, 20 and 50V/V. By default,the LT1999output voltage is referenced halfway between the supply voltage and ground,enabling the output to indicate both the magnitude and direction of the sensedcurrent. The output bias level can be set via a separate input. Gain error isguaranteed at less than 0.5 percent and input offset voltage is guaranteed atless than 1.5 mV over the full temperature range of -40 to 125C. The LT1999operates with an independent 5V supply voltage, drawing 1.5 mA while active and10AmuA in shutdown mode.

Offered in an8-lead MSOP package and 8-lead SOP package, the LT1999family is fully specified over four temperature ranges: 0 to 70, -40 to 85, -40to 125, and -55 to 150C.

Bi-Directional Current Sense Amplifier