Current Sense Amp Features Wide Input Range

Dec 19, 2007 4:56 PM

Linear Technology’s LT6105 is a precision current sense amplifier with an input common mode range that extends from –0.3 V below V-, up to 44 V above V-. The common mode range of the LT6105 is independent of the positive supply voltage, making it ideal for a wide range of applications. As a result, the LT6105 can operate as a high-side or a low-side current sense monitor.

The LT6105 can continuously monitor current during a load short or power supply failure, as well as continuously monitor a battery from full charge to depletion. The LT6105 can directly monitor the current on a negative supply voltage and because the inputs of LT6105 can withstand differential voltages up to ±44V, it is suited to monitoring loads connected through a fuse or a MOSFET switch.

The LT6105 offers an input offset voltage of only 300uV with an input offset drift of 0.5uV/°C of. Any gain between 1 to 100V/V can be designed with external resistors and gain error is limited to less than 1% maximum. The LT6105 operates with an independent supply voltage of 2.85 V to 36 V and draws only 150 µA. When powered down, the sense pins are biased off, which prevents any loading of the sense resistor, irrespective of the sense voltage. Unit pricing starts at $0.99 each in 1,000-piece quantities.