Diodes Incorporated ZXCT181QA1W6-7

Overview

ZXCT181QA1W6-7 from Diodes Incorporated is an AEC-Q100 qualified automotive current shunt monitor optimized for bidirectional and unidirectional low-side/high-side sensing with 20V/V fixed gain, ±1% max gain error over −40°C to +125°C, 400kHz small-signal bandwidth, and operation from 2.7V to 5.5V supply. It measures shunt voltages across −0.3V to 26V common-mode range independent of supply voltage and supports fault current detection in motor control and e-pump systems.

For engineers reviewing the ZXCT181QA1W6-7 datasheet, ZXCT181QA1W6-7 pinout, ZXCT181QA1W6-7 application, or ZXCT181QA1W6-7 equivalent, key selection criteria include its rail-to-rail output swing, 300μA max quiescent current, 20V/V gain accuracy, bi-directional sensing capability via REF pin biasing, and SOT26 package compatibility with automotive PCB layouts.

Technical Context

The ZXCT181QA1W6-7 employs a precision current-sense amplifier topology that enables accurate measurement of differential voltages across shunts at common-mode potentials up to 26V - exceeding its 5.5V max supply voltage. Its input stage operates with ±100μV typical offset and 1μV/°C drift, supporting high-accuracy current reconstruction in noisy automotive environments.

Bi-directional operation is implemented by applying a user-defined reference voltage (0V to VS) to the REF pin, shifting the output baseline to enable symmetric positive/negative current detection. Unidirectional mode uses REF = GND, with ≥50mV bias recommended for low-current linearity - a design constraint directly tied to its 20V/V gain and rail-to-rail output architecture.

Key Specifications

Pinout & Package

Package: 6-pin SOT26 - surface-mount, thermally enhanced outline with 124°C/W junction-to-ambient resistance; suitable for reflow assembly and automotive vibration environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA240A1QDRQ1 and MAX40056ATA+T, the ZXCT181QA1W6-7 delivers superior thermal stability (1.0μV/°C drift), guaranteed AEC-Q100 qualification, and simplified single-supply operation - making it optimal for cost-sensitive, high-volume automotive current monitoring where fixed 20V/V gain suffices.

Availability

ZXCT181QA1W6-7 is available at Aetrix Electronics and suitable for vehicle motor controls, body control modules, and wireless charging systems requiring stable component supply, automotive-grade traceability, and long-term lifecycle support.

Supply support for ZXCT181QA1W6-7 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

Diodes Incorporated is a global semiconductor manufacturer specializing in discrete, analog, and mixed-signal solutions for automotive, industrial, and consumer markets, with ISO/TS 16949-certified production.

The ZXCT181Q belongs to Diodes' automotive-qualified current sense amplifier product line, designed specifically for high-accuracy, high-CMRR shunt-based monitoring in 12V/24V vehicle subsystems operating at extreme temperatures.

FAQ

What is the maximum common-mode voltage the ZXCT181QA1W6-7 can handle?

The ZXCT181QA1W6-7 supports a common-mode input voltage range of −0.3V to +26V, independent of its 2.7V–5.5V supply voltage. This allows direct high-side sensing on 24V automotive batteries without external level-shifting circuitry, and the device remains functional even when VS is unpowered.

How does the REF pin affect bidirectional versus unidirectional operation?

When REF is tied to GND, the device operates unidirectionally - output rises above 0V for positive current but cannot go negative. For bidirectional sensing, apply a bias (e.g., 2.5V) to REF; output then swings symmetrically above/below that voltage, enabling accurate charge/discharge current measurement in battery systems.

Is a bypass capacitor required on the VS pin, and what value is recommended?

Yes - a 0.1μF ceramic capacitor must be placed as close as possible between VS and GND pins to ensure stability and suppress supply noise. Additional bulk capacitance (e.g., 10μF tantalum) may be added for noisy 12V rail inputs, but the 0.1μF local decoupling is mandatory per datasheet layout guidelines.

What is the impact of gain error on current measurement accuracy at full scale?

With ±1% maximum gain error over temperature and ±400μV max offset, the ZXCT181QA1W6-7 introduces ≤±1.2% total error at full-scale output (e.g., 5V). Using a 10mΩ shunt at 10A yields 100mV input; 20× gain gives 2V output, where ±1% gain error equals ±20mV - equivalent to ±2A uncertainty before offset correction.