High Side Current Sense Amplifier has Wide Input Range and Offset
Linear Technology announced the LT6105, a precision 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. Therefore the LT6105 can operate as a high-side or a low-side current sense monitor. It can continuously monitor current during a load short or power supply failure, as well as continuously monitor a battery from full charge to depletion. It can also directly monitor the current on a negative supply voltage, and is ideal for monitoring loads connected through a fuse or a MOSFET switch because the inputs can withstand differential voltages up to ±44V. There is a high level of prcesion due to just 300uV of input offset voltage and only 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 percent maximum. The LT6105 operates with an independent supply voltage of 2.85V to 36V and draws only 150uA. When powered down, the sense pins are biased off, which prevents any loading of the sense resistor, irrespective of the sense voltage. Pricing starts at $0.99 each in 1,000-piece quantities.