Diodes Incorporated ZXCT199B3DW-7

Overview

ZXCT199B3DW-7 from Diodes Incorporated is a zero-drift, bidirectional current shunt monitor IC with 100 V/V fixed gain, −0.1 V to 26 V common-mode input range, ±100 µV max input offset voltage (−40°C to +125°C), and rail-to-rail output swing. It enables high-precision sensing of large currents using low-value shunt resistors (e.g., 1 mΩ at 10 A yields 10 mV drop) in server power supplies and industrial motor controllers.

For engineers reviewing the ZXCT199B3DW-7 datasheet, ZXCT199B3DW-7 pinout, ZXCT199B3DW-7 application, or ZXCT199B3DW-7 equivalent, key selection criteria include bidirectional sensing capability, 100 µA max quiescent current, SOT363 package compatibility, and support for reference-biased operation down to −0.1 V common-mode - critical for high-side/low-side current monitoring in 12 V–24 V systems.

Technical Context

The ZXCT199B3DW-7 implements a precision difference amplifier topology with zero-drift chopper-stabilized architecture, achieving 0.5 µV/°C max offset drift over −40°C to +125°C. Its input stage operates independently of supply voltage, allowing accurate measurement of differential voltages across shunts even when common-mode voltage exceeds V+ (e.g., 26 V CM with 5 V supply).

It supports both unidirectional (REF = GND) and bidirectional (REF = mid-supply, e.g., 2.5 V) configurations via external reference biasing. Output swings from (V_GND + 5 mV) to (V₊ − 50 mV) under 10 kΩ load, enabling direct interface with 12-bit ADCs without level-shifting.

Key Specifications

Pinout & Package

Package: 6-pin SOT363 (2.1 mm × 2.0 mm × 1.0 mm), surface-mount, lead-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA240A1IDR and MAX40056ATA+T, the ZXCT199B3DW-7 uniquely supports direct 2.7–26 V operation with 100 V/V gain and −0.1 V CM capability - simplifying design in 12 V/24 V industrial and telecom power systems without external components.

Availability

ZXCT199B3DW-7 is available at Aetrix Electronics and suitable for server power supply monitoring, industrial motor phase control, telecom rectifier modules, and programmable DC load applications requiring stable component supply, long-lifecycle assurance, and automotive-grade reliability derivatives (ZXCT199Q).

Supply support for ZXCT199B3DW-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 manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and precision analog solutions for industrial, computing, and automotive markets.

The ZXCT199 series belongs to Diodes' precision current sensing product line, engineered specifically for high-accuracy, low-power, wide common-mode current monitoring in space-constrained 12 V–24 V power systems.

FAQ

What is the maximum common-mode voltage the ZXCT199B3DW-7 can measure with a 5 V supply?

The ZXCT199B3DW-7 supports a common-mode input range of −0.1 V to 26 V regardless of supply voltage. With a 5 V V+ supply, it can accurately measure differential voltages across shunts where IN+ and IN− sit at 26 V relative to GND - enabling high-side sensing in 24 V systems without level-shifting circuitry.

How do I configure the ZXCT199B3DW-7 for bidirectional current sensing?

Connect a stable reference voltage (e.g., 2.5 V from a buffered divider or precision reference) to the REF pin. The output then centers at that voltage: positive (IN+ > IN−) currents raise OUT above REF, and negative currents lower OUT below REF. Use low-impedance REF drive to avoid gain/offset errors - an op-amp buffer is recommended for resistor dividers.

Does the ZXCT199B3DW-7 require external gain-setting resistors?

No. The ZXCT199B3DW-7 has a factory-trimmed, fixed 100 V/V gain implemented with laser-trimmed internal thin-film resistors. This eliminates external resistor matching errors, reduces PCB area, and guarantees ±1.0% max gain error over temperature - critical for production calibration stability.

Can the ZXCT199B3DW-7 operate from a 3.3 V supply in low-power systems?

Yes. Its 2.7 V minimum supply voltage supports direct connection to 3.3 V rails. At 3.3 V, the output swings from (GND + 5 mV) to (3.3 V − 50 mV), delivering 3.25 V full-scale range compatible with 3.3 V SAR ADCs. Quiescent current remains ≤100 µA, making it suitable for always-on current telemetry in edge IoT nodes.