Diodes Incorporated ZXCT199C1DW-7

Overview

ZXCT199C1DW-7 from Diodes Incorporated is a zero-drift, bidirectional current-sense amplifier optimized for high-precision shunt monitoring with ±80 μV max input offset voltage, 200 V/V fixed gain, and operation across -0.1 V to 26 V common-mode range. It enables accurate sensing of large currents using low-value shunts (e.g., 1 mΩ at 10 A), supports rail-to-rail output swing, and targets power-supply and server rack current management.

For engineers reviewing the ZXCT199C1DW-7 datasheet, ZXCT199C1DW-7 pinout, ZXCT199C1DW-7 application, or ZXCT199C1DW-7 equivalent, key selection criteria include bidirectional sensing capability, 0.5 μV/°C max offset drift, 2.7–26 V supply range, SOT363 package compatibility, and support for both high-side and low-side configurations with external REF biasing.

Technical Context

The ZXCT199C1DW-7 implements a zero-drift chopper-stabilized architecture to achieve ±80 μV max input offset and 0.5 μV/°C max drift over -40°C to +125°C. Its differential input stage operates independently of supply voltage, allowing measurement of shunt voltages at common-mode potentials up to 26 V while powered from as low as 2.7 V.

It features fixed 200 V/V gain, 105 dB min CMRR over full temperature range, and rail-to-rail output capable of sourcing/sinking ≥1 mA while maintaining ≤200 mV headroom from rails. The REF pin accepts 0 V to V+ bias to configure unidirectional or bidirectional current sensing modes.

Key Specifications

Pinout & Package

Package: 6-pin SOT363 (SC-70-6), 2.1 mm × 2.0 mm × 0.9 mm, surface-mount, RoHS-compliant, halogen-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA240A1D and MAX4080TASA+, the ZXCT199C1DW-7 delivers optimal trade-off of ultra-low offset drift, compact SOT363 packaging, and 200× gain in cost-sensitive industrial and computing applications where 26 V common-mode ceiling is sufficient.

Availability

ZXCT199C1DW-7 is available at Aetrix Electronics and suitable for server rack power monitoring, industrial motor drive protection, high-performance GPU power delivery, and smart energy metering requiring stable component supply across multi-year production cycles.

Supply support for ZXCT199C1DW-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, high-efficiency power management and signal integrity solutions.

The ZXCT199 series belongs to Diodes' precision analog product line, engineered specifically for high-accuracy, low-power current sensing in computing, industrial, and energy infrastructure applications where shunt-based measurement dominates.

FAQ

What is the maximum common-mode voltage the ZXCT199C1DW-7 can measure?

The ZXCT199C1DW-7 supports a common-mode input range of -0.1 V to 26 V, independent of its supply voltage. This means it can accurately measure shunt voltage drops even when the shunt is placed on a 24 V rail while the device itself is powered from only 3.3 V - enabling true high-side sensing without level shifters or isolated supplies.

How does the REF pin enable bidirectional current sensing?

The REF pin sets the output's zero-current baseline voltage. When biased to mid-supply (e.g., 2.5 V on a 5 V rail), positive differential input (IN+ > IN−) produces an output above REF, while negative differential input produces an output below REF - enabling full-scale measurement of both charging and discharging currents through the same shunt resistor.

Can the ZXCT199C1DW-7 be used with a 3.3 V microcontroller ADC?

Yes. With V+ = 3.3 V and REF = 1.65 V, the 200 V/V gain yields a 0–3.3 V output swing for ±8.25 mV shunt voltage - matching standard 3.3 V ADC full-scale range. Output swing remains rail-to-rail within 50 mV of rails, ensuring >12-bit effective resolution when paired with appropriate anti-aliasing filtering.

What is the impact of input filter resistors on measurement accuracy?

Adding unmatched source resistors (>10 Ω) at IN+ or IN− degrades gain accuracy, CMRR, and offset. For example, 20 Ω mismatch introduces ~1.7% gain error in the ZXCT199C1DW-7. To preserve precision, use matched ≤10 Ω resistors with low-inductance layout, or buffer the REF node with an op-amp if using resistive dividers.