Diodes Incorporated ZXCT199C2DW-7

Overview

ZXCT199C2DW-7 from Diodes Incorporated is a zero-drift, bidirectional current shunt monitor IC with 100 V/V fixed gain, ±80 µV max input offset voltage, rail-to-rail output, and operation from 2.7 V to 26 V supply. It measures differential voltages across shunts at common-mode voltages from –0.1 V to 26 V-exceeding its supply voltage-and supports high-precision sensing in server power supplies and industrial motor controllers using low-value (e.g., 0.5 mΩ) shunt resistors.

For engineers reviewing the ZXCT199C2DW-7 datasheet, ZXCT199C2DW-7 pinout, ZXCT199C2DW-7 application, or ZXCT199C2DW-7 equivalent, key selection criteria include bidirectional current sensing capability, 0.5 µV/°C max offset drift over –40°C to +125°C, ±0.8% max gain error over temperature, rail-to-rail output swing, and SOT363 package compatibility with high-density PCB layouts.

Technical Context

The ZXCT199C2DW-7 implements a precision difference amplifier topology with zero-drift chopper-stabilized architecture, enabling stable DC-coupled measurement of sub-millivolt shunt voltages. Its input stage operates independently of supply voltage, allowing accurate sensing at common-mode voltages up to 26 V even with a 2.7 V supply.

It supports both unidirectional (REF = GND) and bidirectional (REF = mid-supply) configurations via external reference voltage control. The 100 V/V gain version delivers 30 kHz bandwidth with 0.5 V/µs slew rate and 25 nV/√Hz input voltage noise density, optimized for low-noise, wide-dynamic-range current monitoring in switched-mode power supplies.

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 ZXCT199C2DW-7 uniquely combines 100 V/V gain, 26 V common-mode tolerance, and user-configurable REF pin-enabling single-component bidirectional sensing in 24 V industrial and telecom systems without external gain or level-shifting.

Availability

ZXCT199C2DW-7 is available at Aetrix Electronics and suitable for server power supplies, industrial motor drives, and telecom rectifier modules requiring stable component supply, long-term lifecycle support, and automotive-qualified alternatives (ZXCT199Q) for future scalability.

Supply support for ZXCT199C2DW-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 company specializing in discrete, analog, and mixed-signal ICs for power management, signal integrity, and protection applications.

The ZXCT199 series belongs to Diodes' precision analog portfolio, designed specifically for high-accuracy, low-drift current sensing in high-reliability industrial, computing, and telecom infrastructure.

FAQ

What is the maximum common-mode voltage the ZXCT199C2DW-7 can measure when powered from 3.3 V?

The ZXCT199C2DW-7 supports common-mode voltages from –0.1 V to 26 V regardless of supply voltage. When powered from 3.3 V, it can still accurately measure shunt voltages at 24 V nodes-such as high-side sensing in 24 V server rails-without external level-shifting circuitry or isolation.

How does the REF pin enable bidirectional current sensing?

The REF pin sets the output voltage corresponding to zero differential input (V_IN+ – V_IN− = 0). With REF = 2.5 V and V+ = 5 V, the output swings from 0 V to 5 V: values below 2.5 V indicate reverse current flow, while values above indicate forward flow-enabling true bidirectional measurement in battery charging/discharging systems.

Can the ZXCT199C2DW-7 drive an ADC input directly without a buffer?

Yes-the rail-to-rail output drives 10 kΩ loads and interfaces directly with most SAR and delta-sigma ADC inputs. For 12-bit+ accuracy, use a 0.1 µF ceramic bypass capacitor at V+ and route REF from a low-impedance source (e.g., buffered divider) to avoid gain error from REF pin impedance effects.

What is the impact of input filtering resistors on gain accuracy?

Adding unmatched series resistors at IN+ and IN− degrades CMRR and introduces gain error. With 10 Ω matched resistors, ZXCT199C2DW-7 exhibits ~0.89% gain error; exceeding 10 Ω increases error nonlinearly. Use matched <10 Ω resistors only if transient filtering is essential-and recalculate gain error using Diodes' published equations.