Diodes Incorporated ZXCT199A3DW-7

Overview

ZXCT199A3DW-7 from Diodes Incorporated is a zero-drift, bidirectional current shunt monitor IC with 200V/V fixed gain, operating from 2.7V to 26V supply, supporting common-mode input voltages from –0.1V to 26V, and delivering rail-to-rail output swing with max 80μV offset voltage (C version) and 0.5μV/°C drift - used for precision high-current sensing in server power supplies and industrial motor controllers.

For engineers reviewing the ZXCT199A3DW-7 datasheet, ZXCT199A3DW-7 pinout, ZXCT199A3DW-7 application, or ZXCT199A3DW-7 equivalent, key selection criteria include bidirectional sensing capability, 200V/V gain accuracy over –40°C to +125°C, SOT363 package thermal performance, and REF-pin configurable zero-current reference for charging/discharging monitoring.

Technical Context

The ZXCT199A3DW-7 implements a zero-drift chopper-stabilized amplifier architecture to achieve <80μV input offset and <0.5μV/°C drift across –40°C to +125°C. Its differential input stage operates independently of supply voltage, enabling accurate measurement of shunt voltage at common-mode potentials up to 26V even when V+ = 2.7V.

It supports both unidirectional (REF = GND) and bidirectional (REF = mid-supply) operation via external reference configuration. Output swings rail-to-rail (V_OH = V+ – 0.05V, V_OL = GND + 5mV) into 10kΩ loads, with 14kHz bandwidth and 25nV/√Hz input voltage noise - optimized for low-value shunt (<1mΩ) current monitoring in high-efficiency power systems.

Key Specifications

Pinout & Package

Package: 6-pin SOT363 (2.1mm × 2.0mm × 1.0mm, 0.65mm pitch), thermally enhanced for 228°C/W junction-to-ambient dissipation.

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 ZXCT199A3DW-7 uniquely supports 26V common-mode at 2.7V supply with 80μV offset and SOT363 footprint - making it the only option for space-constrained, wide-input-range, high-accuracy bidirectional sensing in 12V–48V industrial power systems.

Availability

ZXCT199A3DW-7 is available at Aetrix Electronics and suitable for server power supplies, industrial motor drives, telecom rectifiers, and battery energy storage systems requiring stable component supply across extended temperature and long product lifecycles.

Supply support for ZXCT199A3DW-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 targets high-precision current sensing in high-efficiency power conversion systems - designed specifically for low-shunt-voltage, wide common-mode, and extended temperature operation in computing, industrial, and telecom infrastructure.

FAQ

What is the maximum common-mode voltage the ZXCT199A3DW-7 can measure when powered from 3.3V?

The ZXCT199A3DW-7 supports common-mode input voltages from –0.1V to 26V regardless of supply voltage. When powered from 3.3V, it can still accurately measure shunt voltages across a 24V bus - a key advantage over conventional current sense amplifiers limited by supply rail constraints.

How does the REF pin enable bidirectional current measurement?

The REF pin sets the output voltage corresponding to zero differential input (i.e., zero current). Applying V+/2 to REF creates symmetric ±output swing: positive shunt voltage produces OUT > V+/2 (discharge), negative shunt voltage produces OUT < V+/2 (charge), enabling true bidirectional sensing without polarity switching.

Can the ZXCT199A3DW-7 drive an ADC input directly without external buffering?

Yes - its rail-to-rail output (V_OL = GND + 5mV, V_OH = V+ – 50mV) and 10kΩ minimum load drive capability allow direct connection to most SAR and sigma-delta ADCs. For optimal accuracy, use differential ADC inputs referenced to the same REF voltage to cancel REF-path errors.

What is the impact of adding series resistors at IN+ and IN− for ESD protection?

Adding unmatched series resistors >10Ω degrades CMRR, gain accuracy, and offset. If required, use matched ≤10Ω resistors and buffer REF with an op-amp; otherwise, rely on internal 5kV HBM ESD protection. The datasheet provides gain error formulas for RS = 10Ω, 20Ω, and 30.1Ω.