LT1999-10/LT1999-20/ LT1999-50 - High Voltage, Bidirectional Current Sense Amplifier - Linear Technology - #1

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LT1999-10/LT1999-20/ LT1999-50 1 1999fa TYPICAL APPLICATION FEATURES DESCRIPTION High Voltage, Bidirectional Current Sense Amplifier The LT®1999 is a high speed precision current sense amplifier, designed to monitor bidirectional currents over a wide common mode range. The LT1999 is offered in three gain options: 10V/V, 20V/V, and 50V/V. The LT1999 senses current via an external resistive shunt and generates an output voltage, indicating both magnitude and direction of the sensed current. The output voltage is referenced halfway between the supply voltage and ground, or an external voltage can be used to set the reference level. With a 2MHz bandwidth and a common mode input range of –5V to 80V, the LT1999 is suitable for monitoring currents in H-Bridge motor controls, switching power supplies, solenoid currents, and battery charge currents from full charge to depletion. The LT1999 operates from an independent 5V supply and draws 1.55mA. A shutdown mode is provided for minimizing power consumption. The LT1999 is available in an 8-lead MSOP or SOP package. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. APPLICATIONS n Buffered Output with 3 Gain Options: 10V/V, 20V/V, 50V/V n Gain Accuracy: 0.5% Max n Input Common Mode Voltage Range: –5V to 80V n AC CMRR > 80dB at 100kHz n Input Offset Voltage: 1.5mV Max n –3dB Bandwidth: 2MHz n Smooth, Continuous Operation Over Entire Common Mode Range n 4kV HBM Tolerant and 1kV CDM Tolerant n Low Power Shutdown <10ìA n –55°C to 150°C Operating Temperature Range n 8-Lead MSOP and 8-Lead SO (Narrow) Packages n High Side or Low Side Current Sensing n H-Bridge Motor Control n Solenoid Current Sense n High Voltage Data Acquisition n PWM Control Loops n Fuse/MOSFET Monitoring Full Bridge Armature Current Monitor TIME (10ìs/DIV) 2.5V VOUT (2V/DIV) V+IN (20V/DIV) 1999 TA01b VOUT V+IN LT1999 4k 0.8k 160k 160k 2ìA 4k 0.8k SHDN 5V V+ V+ 5V V+ RS 1999 TA01a + – + – VS 1 8 2 3 4 7 6 5 0.1ìF 0.1ìF VOUT RG V+IN V–IN VREF VSHDN V+ V+