Analog Devices Inc. LT6109AHMS-1#PBF

Overview

LT6109AHMS-1#PBF from Analog Devices (formerly Linear Technology) is a high-side current sense amplifier with integrated 400mV precision reference and dual latching comparators configured in opposing polarity (LT6109-1 variant). It delivers 125µV max input offset, 0.2% max gain error, and 1.4µs typical propagation delay for overcurrent/undercurrent fault detection in industrial and automotive power systems. Its 2.7V–60V supply range and –40°C to 125°C operation support battery monitoring and motor control applications.

For engineers reviewing the LT6109AHMS-1#PBF datasheet, LT6109AHMS-1#PBF pinout, LT6109AHMS-1#PBF application, or LT6109AHMS-1#PBF equivalent, key selection criteria include its 10-lead MSOP package, comparator polarity configuration (opposing), latch/reset timing (2–15µs pulse width), and ability to operate with V+ up to 60V while sensing differential voltages across shunt resistors up to 500mV full-scale.

Technical Context

The LT6109AHMS-1#PBF implements a high-impedance current-output sense amplifier that forces SENSEHI to match SENSELO potential, generating I_OUTA = V_SENSE/R_IN. Its two comparators share an internal 400mV reference but are wired with opposite polarity - one triggers on rising input (overcurrent), the other on falling input (undercurrent) - enabling simultaneous high- and low-threshold fault detection.

Each comparator features ±1.25% total threshold error, 10mV hysteresis, and open-drain outputs capable of sinking 500µA at 2.7V supply while tolerating up to 60V pull-up voltage relative to V–. The EN/RST pin enables shutdown (I_Q ≤ 5µA) and provides asynchronous reset of latched comparator states with 0.5µs reset time.

Key Specifications

Pinout & Package

LT6109AHMS-1#PBF is housed in a 10-lead MSOP package (3mm × 3mm, 0.5mm pitch) with exposed pad for thermal enhancement. Pin numbering follows standard top-view orientation with Pin 1 at bottom-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-side current sense amplifier applications.

Compared with MAX4008AASA+ and INA302A3IDR, the LT6109AHMS-1#PBF uniquely integrates dual latching comparators with opposing polarity, a precision 400mV reference, and 60V operation - making it optimal for safety-critical, high-voltage applications requiring persistent fault state retention and minimal external components.

Availability

LT6109AHMS-1#PBF is available at Aetrix Electronics and suitable for battery monitoring, motor control, and automotive monitoring applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LT6109AHMS-1#PBF 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 acquired Linear Technology in 2017 and maintains full product support, documentation, and manufacturing continuity for the LT6109 family.

The LT6109 series was designed specifically for high-reliability high-side current sensing in harsh environments, emphasizing low offset, wide supply range, and integrated fault detection with latch capability for automotive and industrial power systems.

FAQ

What is the maximum sense voltage supported by the LT6109AHMS-1#PBF before accuracy degrades?

The LT6109AHMS-1#PBF specifies a full-scale input sense voltage (V_SENSE(MAX)) of 500mV. While the device can tolerate higher differential inputs without damage, output accuracy degrades beyond this point due to increased output current and associated errors. For guaranteed performance per datasheet specifications, V_SENSE must remain ≤500mV under all operating conditions, including peak load transients.

How does the LT6109AHMS-1#PBF differ from the LT6109AHMS-2#PBF variant?

The LT6109AHMS-1#PBF uses opposing-polarity comparators - one detects overcurrent (rising threshold), the other undercurrent (falling threshold). In contrast, the LT6109AHMS-2#PBF configures both comparators with the same polarity, enabling dual overcurrent thresholds or window-based detection. Pinout, package, and core amplifier specs are identical between the two variants.

Can the LT6109AHMS-1#PBF be used in a 48V telecom power system?

Yes - the LT6109AHMS-1#PBF supports supply voltages up to 60V and common-mode input ranges extending to V+ + 1V, making it fully compatible with 48V nominal telecom power shelves. Its –40°C to 125°C qualification, 125µV offset, and 1.4µs fault response meet stringent requirements for hot-swap controllers and redundant power monitoring in NEBS-compliant equipment.

What is the minimum pulse width required on the EN/RST pin to reset the latched comparators in the LT6109AHMS-1#PBF?

The LT6109AHMS-1#PBF requires a low-going pulse on the EN/RST pin with duration between 2µs and 15µs to reliably reset both latched comparators. Pulses shorter than 2µs may fail to trigger reset; pulses longer than 15µs will force the device into shutdown mode instead of reset. This timing is specified across the full –40°C to 125°C temperature range.

Does the LT6109AHMS-1#PBF require external passive components to operate as a basic current sensor?

Yes - the LT6109AHMS-1#PBF requires at minimum an external input resistor (R_IN) between SENSEHI and V+, and an output resistor (R_OUT) from OUTA to V–, to convert sensed voltage into usable current and then voltage outputs. Comparator thresholds are set via additional resistive dividers connected to INC1/INC2. No external reference is needed due to the integrated 400mV precision reference.