Allegro MicroSystems A1366LKTTF-5-T

Overview

A1366LKTTF-5-T from Allegro MicroSystems is a factory-programmed linear Hall-effect current sensor IC designed for high-accuracy bidirectional current sensing in automotive power electronics. It delivers 5 mV/G sensitivity, ±0.25% linearity error, 120 kHz analog bandwidth, and operates across –40°C to 150°C - enabling precise real-time current monitoring in HEV inverter legs and electric power steering (EPS) motor control circuits.

For engineers reviewing the A1366LKTTF-5-T datasheet, A1366LKTTF-5-T pinout, A1366LKTTF-5-T application, or A1366LKTTF-5-T equivalent, key selection criteria include its ratiometric analog output, factory-trimmed temperature-flat sensitivity, built-in broken-ground-wire detection, and AEC-Q100 qualification for under-hood deployment.

Technical Context

The A1366LKTTF-5-T integrates a BiCMOS interface with a proprietary chopper-stabilized Hall element, dynamic offset cancellation, and digital-domain segmented linear interpolation temperature compensation stored in on-chip EEPROM. This architecture maintains <±1% typical total accuracy over temperature without degrading analog signal path bandwidth.

Its functional block includes VCC-powered signal conditioning, internal 500 kHz chopping frequency for noise reduction, open-circuit ground detection logic, undervoltage lockout (UVLO) with 3.5 V/4 V thresholds, and a low-impedance rail-to-rail-capable output stage delivering 2.5 V quiescent voltage at 5 V supply.

Key Specifications

Pinout & Package

The A1366LKTTF-5-T is housed in a 4-pin single in-line package (SIP), suffix KT, with 1 mm case thickness, Pb-free construction, and 100% matte tin leadframe plating. The package is optimized for surface-mount assembly and thermal performance (R_θJA = 174 °C/W on 1-layer PCB).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar linear Hall-effect current sensing applications.

Compared with ACS724LLCTR-5AB-T and TLE4971-5U, the A1366LKTTF-5-T provides fixed high-precision analog output with zero configuration overhead, superior temperature flatness, and integrated open-ground diagnostics - making it optimal for deterministic, safety-critical analog feedback loops in automotive power stages.

Availability

A1366LKTTF-5-T is available at Aetrix Electronics and suitable for hybrid electric vehicle inverter design, electric power steering systems, and high-reliability DC-DC converter development requiring stable component supply through production ramp.

Supply support for A1366LKTTF-5-T 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

Allegro MicroSystems is a U.S.-based semiconductor company specializing in high-performance magnetic sensing and power ICs for automotive and industrial motion control.

The A1366 product line was engineered specifically for high-accuracy, high-bandwidth current sensing in demanding automotive electrification applications - emphasizing temperature stability, diagnostic integrity, and AEC-Q100 compliance from wafer to package.

FAQ

What is the sensitivity value of the A1366LKTTF-5-T, and how is it programmed?

The A1366LKTTF-5-T has a factory-programmed sensitivity of 5 mV/G, measured at 200 G and 25°C. This value is permanently stored in on-chip EEPROM using Allegro's proprietary linear interpolation temperature compensation algorithm, ensuring minimal drift across –40°C to +150°C. No user programming or external calibration is required - the A1366LKTTF-5-T ships ready for immediate integration into current-sensing circuits.

Does the A1366LKTTF-5-T support bidirectional current sensing?

Yes, the A1366LKTTF-5-T supports true bidirectional magnetic field detection: a south-pole field increases VOUT above its 2.5 V quiescent level, while a north-pole field decreases it symmetrically. Its <±0.25% symmetry sensitivity error and ratiometric output ensure matched positive/negative gain and zero-point stability - critical for accurate net-current measurement in H-bridge or inverter leg configurations using the A1366LKTTF-5-T.

What diagnostic features does the A1366LKTTF-5-T include?

The A1366LKTTF-5-T integrates two hardware-level diagnostics: open-circuit detection on the GND pin (broken wire) and undervoltage lockout (UVLO) with 3.5 V/4 V thresholds. When GND is disconnected, VOUT shifts to either VCC or GND depending on external pull configuration - providing immediate fault signaling without MCU intervention. These diagnostics are active across the full –40°C to +150°C range and are integral to the A1366LKTTF-5-T's AEC-Q100 Grade 0 qualification.

Is the A1366LKTTF-5-T pin-compatible with other variants in the A1366 family?

Yes, all A1366 variants - including A1366LKTTF-1-T, A1366LKTTF-2-T, A1366LKTTF-5-T, and A1366LKTTF-10-T - share identical 4-pin SIP (KT) packaging, pinout, and electrical interface. Only sensitivity and noise performance differ between variants; no PCB layout change is needed when upgrading or downgrading sensitivity within the A1366 family, simplifying design reuse and qualification for the A1366LKTTF-5-T and its siblings.

What is the maximum recommended capacitive load on the A1366LKTTF-5-T VOUT pin?

The A1366LKTTF-5-T VOUT pin is specified to drive capacitive loads up to 10 nF while maintaining stability and specified response time (t_R = 3.6 µs, t_RESPONSE = 3.7 µs). For optimal high-frequency fidelity and minimal overshoot, Allegro recommends limiting CL to ≤1 nF in most applications - especially those requiring full 120 kHz bandwidth. Exceeding 10 nF may cause instability or degraded transient response in the A1366LKTTF-5-T output stage.