High side current sense amplifier

Linear Technology announces the LT6105, a current sense amplifier with an input common mode range that extends from –0.3V below V-, up to 44V above V-. The common mode range of the LT6105 is independent of the positive supply voltage. As a result, the device 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 chip 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 ideal for monitoring loads connected through a fuse or a MOSFET switch. The device offers precision with 300uV of input offset voltage and 0.5uV/°C of input offset drift. 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 2.85V to 36V and draws 150uA. When powered down, the sense pins are biased off, which prevents any loading of the sense resistor, irrespective of the sense voltage.