Analog Devices Inc. LT1999HMS8-50#TRPBF

Overview

LT1999HMS8-50#TRPBF from Analog Devices is a high-voltage, bidirectional current sense amplifier with 50V/V fixed gain, –5V to 80V input common mode range, 2MHz bandwidth, and ±0.5% gain accuracy. It operates from a 4.5V–5.5V supply, draws 1.55mA, and supports high-side or low-side shunt monitoring in automotive H-bridge motor controls and battery charge/discharge systems.

For engineers reviewing the LT1999HMS8-50#TRPBF datasheet, LT1999HMS8-50#TRPBF pinout, LT1999HMS8-50#TRPBF application, or LT1999HMS8-50#TRPBF equivalent, this page delivers verified electrical specs, FMEA-optimized MSOP-8 pin configuration, thermal performance up to 125°C ambient, and real-world use cases in PWM-controlled power stages and fuse/MOSFET health monitoring.

Technical Context

The LT1999HMS8-50#TRPBF uses matched on-chip resistor networks (R_+IN/R_−IN = 4kΩ each) and transconductance amplification to convert differential shunt voltage into a level-shifted output referenced to the REF pin. Its architecture enables smooth, continuous operation across the full –5V to 80V common mode range without gain discontinuity or offset shift.

It integrates internal 160kΩ/160kΩ resistive divider for mid-supply REF bias, supports external REF override (1.125V to V₊–1.125V), and features 2µA internal SHDN pull-up enabling default-active operation. The 50V/V gain version uses a nominal 200kΩ internal RG resistor, yielding ±0.08V full-scale input sense voltage at ≤0.5% gain error.

Key Specifications

Pinout & Package

LT1999HMS8-50#TRPBF is housed in an 8-lead plastic MSOP package with FMEA-optimized pinout (pin 3 = NC), designed to prevent misconnection-induced failure in safety-critical systems. Package dimensions: 3.0mm × 3.0mm × 1.1mm, θ_JA = 300°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage bidirectional current sensing applications.

Compared with INA240A1QDRQ1 and MAX40056ATA+T, the LT1999HMS8-50#TRPBF uniquely combines FMEA-optimized MSOP pinout, guaranteed 1.2MHz bandwidth at 50V/V gain, and integrated mid-supply REF bias - making it optimal for automotive H-bridge and industrial servo designs requiring both functional safety and dynamic accuracy.

Availability

LT1999HMS8-50#TRPBF is available at Aetrix Electronics and suitable for automotive H-bridge motor control, battery management systems, and industrial power supply design requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LT1999HMS8-50#TRPBF includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LT1999 family was engineered specifically for high-voltage, high-accuracy bidirectional current sensing in safety-critical power systems - emphasizing robustness across wide common mode ranges, FMEA-aware packaging, and AEC-Q100 qualification for automotive deployment.

FAQ

What is the maximum common mode voltage the LT1999HMS8-50#TRPBF can handle?

The LT1999HMS8-50#TRPBF supports an input common mode voltage range of –5V to 80V, verified across its full operating temperature range of –40°C to 125°C. This allows direct sensing on high-side MOSFET sources in 48V and 60V industrial systems without level-shifting circuitry. Absolute maximum ratings extend to –5.25V and 88V for short-duration transients, but sustained operation beyond 80V may degrade performance or reliability.

Does the LT1999HMS8-50#TRPBF require external components for basic operation?

The LT1999HMS8-50#TRPBF operates with only two external bypass capacitors (0.1µF on V+ and REF) and a shunt resistor. Its internal 160kΩ/160kΩ divider sets REF to mid-supply by default, eliminating need for external biasing. No gain-setting resistors are required - the 50V/V ratio is laser-trimmed on-die. External RC filtering on OUT is optional and only needed for loads exceeding 200pF capacitance.

How does the FMEA-optimized pinout of the LT1999HMS8-50#TRPBF improve system reliability?

The LT1999HMS8-50#TRPBF uses an FMEA-optimized MSOP-8 pinout where Pin 3 is designated NC (no connect). This prevents catastrophic failure modes such as accidental shorting of +IN or –IN to V+ during solder bridging, probe contact, or PCB trace errors. Unlike standard MSOP variants, this layout eliminates single-point wiring faults that could disable current sensing or damage downstream circuitry - a key requirement for ISO 26262 ASIL-B compliant designs.

Can the LT1999HMS8-50#TRPBF be used in bidirectional battery monitoring applications?

Yes, the LT1999HMS8-50#TRPBF is explicitly designed for bidirectional current sensing. Its output voltage polarity relative to the REF pin indicates current direction: positive deviation means current flows from +IN to –IN; negative deviation means reverse flow. With ±0.5% gain accuracy and ±500µV input offset, it delivers reliable zero-crossing detection and charge/discharge quantification in 12V–48V battery systems, supporting coulomb counting and state-of-charge estimation.

What is the shutdown behavior of the LT1999HMS8-50#TRPBF and how is it controlled?

The LT1999HMS8-50#TRPBF enters ultra-low-power shutdown (<10µA) when the SHDN pin (Pin 8) is pulled to ≤0.5V. It defaults to active mode due to an internal 2µA pull-up current source - no external pull-up is required. Turn-on and turn-off times are both ≤1µs, enabling rapid enable/disable cycles in burst-mode power supplies. During shutdown, the output is high-impedance, preventing loading of downstream circuitry.