Allegro MicroSystems A1366LKTTG-1-T

Overview

A1366LKTTG-1-T from Allegro MicroSystems is a factory-programmed linear Hall-effect current sensor IC designed for high-accuracy, high-bandwidth current sensing in automotive power electronics. It delivers 1 mV/G sensitivity, ±0.25% linearity error, and 120 kHz analog bandwidth with ratiometric voltage output referenced to VCC. Its integrated temperature compensation ensures <±1% typical total accuracy across –40°C to 150°C, making it suitable for HEV inverter phase-leg monitoring and electric power steering (EPS) motor current feedback.

For engineers reviewing the A1366LKTTG-1-T datasheet, A1366LKTTG-1-T pinout, A1366LKTTG-1-T application, or A1366LKTTG-1-T equivalent, key selection criteria include its 4-pin SIP package, broken-ground-wire detection, 2.5 V quiescent output, AEC-Q100 qualification, and factory-trimmed sensitivity stability over temperature and lifetime.

Technical Context

The A1366LKTTG-1-T implements digital-domain segmented linear interpolated temperature compensation using on-chip EEPROM, preserving full analog signal path bandwidth. Its BiCMOS interface integrates a low-noise amplifier, dynamic offset cancellation, and chopper stabilization to achieve 1.1 mG/√Hz noise density and 120 kHz –3 dB bandwidth.

It features built-in open-circuit detection on GND, undervoltage lockout (VUVLOH = 4 V), power-on reset (VPORH = 2.6 V), and proprietary circuits suppressing output spiking during fast current transients - all operating within a 4.5–5.5 V supply range and 10 mA supply current.

Key Specifications

Pinout & Package

The A1366LKTTG-1-T is housed in a 4-pin single in-line package (SIP, suffix KT), 1 mm thick, Pb-free with 100% matte tin leadframe plating. The package is AEC-Q100 qualified and optimized for thermal performance (RθJA = 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-1B-T and TLE4971-2K5M6XUMA1, the A1366LKTTG-1-T offers guaranteed 1 mV/G sensitivity with no host intervention, superior temperature flatness (<±1% vs. ±2.5%), and built-in broken-wire detection - reducing validation effort in ASIL-B automotive designs.

Availability

A1366LKTTG-1-T is available at Aetrix Electronics and suitable for HEV inverter monitoring, electric power steering (EPS) motor control, and DC-DC converter current sensing requiring stable component supply across extended temperature ranges and automotive lifecycle demands.

Supply support for A1366LKTTG-1-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 magnetic sensing and power ICs for automotive and industrial motion control.

The A1366 product line was developed specifically for high-accuracy, high-bandwidth current sensing in electrified vehicle powertrain systems - emphasizing factory-trimmed precision, AEC-Q100 reliability, and integrated diagnostics.

FAQ

What is the sensitivity tolerance of the A1366LKTTG-1-T over temperature?

The A1366LKTTG-1-T has a sensitivity drift of ±2.5% over the full operating temperature range (–40°C to +150°C), with typical total accuracy better than ±1% due to its proprietary segmented linear interpolated temperature compensation. This specification is confirmed in the A1366LKT-1-T PERFORMANCE CHARACTERISTICS table on page 7 of the datasheet, where ∆SensTC is bounded at ±2.5% and factory TC achieves <±1% typical system-level error. The A1366LKTTG-1-T maintains this performance without external calibration.

Does the A1366LKTTG-1-T require an external bypass capacitor?

Yes, the A1366LKTTG-1-T requires a 0.1 µF ceramic bypass capacitor between VCC (pin 1) and GND (pin 4), placed as close as possible to the device. This is explicitly mandated in the Terminal List Table and Functional Description sections to ensure stable operation, suppress supply noise, and maintain full 120 kHz bandwidth. Omitting or misplacing this capacitor degrades noise performance and may cause output instability. The A1366LKTTG-1-T datasheet specifies CBYPASS = 0.1 µF for all electrical characteristics.

How does broken ground wire detection work on the A1366LKTTG-1-T?

The A1366LKTTG-1-T monitors continuity of the GND pin (pin 4) and asserts a fault condition if disconnected. When GND opens, VOUT shifts to VBRK(HIGH) ≈ VCC (if pulled up) or VBRK(LOW) ≤ 100 mV (if pulled down), providing a clear diagnostic signal. This feature is implemented via internal circuitry described in the Absolute Maximum Ratings and Electrical Characteristics tables, and is validated per AEC-Q100 requirements. It enables fail-safe behavior in automotive systems without external supervision - a core capability of the A1366LKTTG-1-T.

Is the A1366LKTTG-1-T pin-compatible with other A1366 variants like A1366LKTTN-2-T?

Yes, the A1366LKTTG-1-T shares identical 4-pin SIP (KT) package, pinout, and footprint with all A1366LKT-x-T variants including A1366LKTTN-2-T, A1366LKTTN-5-T, and A1366LKTTN-10-T. All variants use pins 1 (VCC), 2 (VOUT), 3 (NC), and 4 (GND) with identical mechanical dimensions and thermal characteristics. However, sensitivity, noise, and lifetime drift differ by variant - the A1366LKTTG-1-T is specifically calibrated to 1 mV/G, and substitution requires verification of system-level gain and error budget.

What is the maximum capacitive load the A1366LKTTG-1-T can drive on VOUT?

The A1366LKTTG-1-T guarantees stable operation with capacitive loads up to 10 nF on VOUT (pin 2), as specified in the Electrical Characteristics table under "Output Load Capacitance [4]". This allows direct connection to ADC input filters or long traces without oscillation. For optimal step response (e.g., tR = 3.6 µs), Allegro recommends CL = 1 nF; larger values increase rise time but remain within specification up to 10 nF. The A1366LKTTG-1-T's 9 Ω output resistance and internal compensation ensure stability across this range without external isolation components.