Allegro MicroSystems ASEK730KLC-40AB-T-DK

Overview

ASEK730KLC-40AB-T-DK from Allegro MicroSystems is a galvanically isolated, bidirectional current sensor IC in an 8-pin SOIC package, delivering 1 MHz bandwidth, ±40 A sensing range, 50 mV/A sensitivity, 5 V single-supply operation, and 1.2 mΩ primary conductor resistance for low-loss high-current monitoring in motor drives and power converters.

For engineers reviewing the ASEK730KLC-40AB-T-DK datasheet, ASEK730KLC-40AB-T-DK pinout, ASEK730KLC-40AB-T-DK application, or ASEK730KLC-40AB-T-DK equivalent, key selection criteria include isolation rating (2400 VRMS), temperature-stable offset (±20 mV over –40°C to 125°C), total output error (±5% at full scale), and compatibility with space-constrained PCB layouts requiring basic isolation per UL 62368-1.

Technical Context

The ASEK730KLC-40AB-T-DK integrates a linear Hall sensor with a low-resistance copper conduction path (pins 1–4) magnetically coupled to signal terminals (pins 5–8), enabling high-side current sensing without external isolation. Its proprietary amplifier and filter design achieves 1 MHz small-signal bandwidth while maintaining 40 µA/√Hz input-referred noise density.

Patented digital temperature compensation corrects sensitivity and offset drift across –40°C to 125°C, and an integrated magnetic shield minimizes capacitive coupling from dV/dt transients on the primary conductor. The device outputs a ratiometric analog voltage (VIOUT) centered at 2.5 V at zero current, referenced to VZCR.

Key Specifications

Pinout & Package

The ASEK730KLC-40AB-T-DK is housed in an 8-pin SOICN (Small Outline Integrated Circuit, Narrow) package with gull-wing leads, 100% matte tin plating, and RoHS-compliant Pb-based solder bumps (per "-T" suffix). Creepage and clearance are ≥4 mm; distance through insulation is 44 µm.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar current sensing applications.

Compared with ASEK730KLC-40AB-T-DK, ACS37030 offers superior speed and noise performance but sacrifices ratiometric referencing and full-range accuracy over temperature, while CT428 provides higher current range at lower cost but requires external calibration for stable operation beyond 25°C.

Availability

ASEK730KLC-40AB-T-DK is available at Aetrix Electronics and suitable for motor control, switched-mode power supplies, overcurrent fault protection, and energy metering requiring stable component supply and long-term lifecycle support.

Supply support for ASEK730KLC-40AB-T-DK 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 designer and manufacturer of high-performance magnetic sensing and power IC solutions, specializing in Hall-effect sensors, current sensors, and motor driver ICs.

The ACS730 family was engineered for high-accuracy, galvanically isolated current sensing in industrial and commercial power systems, emphasizing bandwidth, thermal stability, and ease of integration in space-constrained PCBs.

FAQ

What is the maximum continuous current rating for ASEK730KLC-40AB-T-DK?

The ASEK730KLC-40AB-T-DK is rated for ±40 A continuous primary current at TA = 25°C. Derating applies above 25°C ambient; junction temperature must remain ≤165°C. At 125°C ambient, continuous current is limited to approximately ±25 A based on thermal modeling of the 1.2 mΩ conduction path and package thermal resistance.

Does ASEK730KLC-40AB-T-DK require external filtering capacitors?

Yes, ASEK730KLC-40AB-T-DK requires a 0.1 µF bypass capacitor between VCC and GND (CBYPASS), and a 1 nF capacitor between VZCR and GND (CVZCR), as specified in the functional schematic. These capacitors stabilize the internal regulator and suppress high-frequency noise on the reference output, directly impacting measurement accuracy and bandwidth fidelity.

How does the VZCR pin improve measurement accuracy in ASEK730KLC-40AB-T-DK?

The VZCR pin in ASEK730KLC-40AB-T-DK provides a buffered 2.5 V reference that matches the VIOUT quiescent voltage at zero current. When used differentially (e.g., VIOUT – VZCR), it cancels common-mode offset drift and supply variations, improving effective resolution and long-term stability-especially critical in precision current loops where absolute zero-current accuracy matters.

Is ASEK730KLC-40AB-T-DK suitable for high-voltage DC applications like EV battery monitoring?

No-ASEK730KLC-40AB-T-DK is rated for basic isolation only (420 VPK working voltage per UL 62368-1), making it unsuitable for direct connection to >400 V DC battery buses. It is designed for secondary-side or auxiliary power rail monitoring in EV chargers and onboard converters, not primary traction battery current sensing which requires reinforced isolation.

What does the "-T" suffix indicate in ASEK730KLC-40AB-T-DK?

The "-T" suffix in ASEK730KLC-40AB-T-DK denotes Pb-based solder bumps manufactured under RoHS exemptions (Annex III/IV, exemptions 7(a), 15, 15a). Electrical and thermal performance is identical to "-S" variants; the distinction is solely in solder composition and regulatory compliance path-not functionality, reliability, or pinout.