LT1999CMS8-20#PBF

Instrumentation, Op Amps, Buffer Amps Overview

The LT1999CMS8-20#PBF is a high-speed precision current sense amplifier manufactured by Analog Devices Inc. It features a fixed gain of 20V/V and operates from an independent 5V supply with a typical quiescent current of 1.55mA. The device supports bidirectional current monitoring over a wide common mode input range of –5V to 80V. Key electrical specifications include a 2MHz small-signal bandwidth, a slew rate of 3V/µs, and a maximum input offset voltage of 1.5mV. It is housed in an 8-lead MSOP package and is rated for commercial operating temperatures from 0°C to 70°C.

Instrumentation, Op Amps, Buffer Amps Feature Summary

• Provides buffered output with a fixed gain of 20V/V and maximum gain accuracy of 0.5%.
• Supports smooth, continuous operation across the entire common mode input range from –5V to 80V.
• Includes a low power shutdown mode that reduces supply current to less than 10µA.
• Features high immunity to electromagnetic interference with AC CMRR greater than 80dB at 100kHz.

Instrumentation, Op Amps, Buffer Amps Applications

• H-Bridge motor control systems
• Switching power supplies
• Solenoid current sensing
• Battery charge current monitoring

Instrumentation, Op Amps, Buffer Amps Procurement Notes

Verify the specific suffix #PBF indicates lead-free finish and RoHS compliance when sourcing. Confirm the temperature grade 'C' corresponds to the required 0°C to 70°C operational range for your application environment. Ensure the 8-lead MSOP package dimensions match your PCB footprint requirements before finalizing procurement orders.

Instrumentation, Op Amps, Buffer Amps Selection Notes

Select this component when a fixed 20V/V gain is required for bidirectional current sensing applications. Consider the LT1999-10 or LT1999-50 variants if different gain factors are needed. Evaluate the wider temperature grades (I, H, MP) if the operating environment exceeds the commercial 0°C to 70°C limit. Verify that the 80V common mode range meets the system's voltage requirements.

Instrumentation, Op Amps, Buffer Amps Part Context

This part belongs to the LT1999 family of high-voltage, bidirectional current sense amplifiers. The series offers three gain options: 10V/V, 20V/V, and 50V/V. The CMS8 designation identifies the commercial temperature grade and the 8-lead MSOP plastic package. The family is designed for high-side or low-side sensing in industrial and automotive environments.

Instrumentation, Op Amps, Buffer Amps Replacement Considerations

Direct replacements within the same family include LT1999CMS8-10#PBF and LT1999CMS8-50#PBF, which share identical pinouts but offer different gains. For automotive applications, consider the AEC-Q100 qualified LT1999HMS8-20F#WPBF variant.

Instrumentation, Op Amps, Buffer Amps FAQ

How does the REF pin function?

The REF pin sets the output common mode level. It defaults to mid-supply via internal resistors but can be overdriven by an external voltage source to shift the output reference point.

What is the purpose of the SHDN pin?

The SHDN pin controls the shutdown mode. Pulling it below 0.5V minimizes power consumption, while leaving it floating activates the internal pull-up to keep the amplifier in the active state.