Monolithic Power Systems Inc. MCS1803GS-20-Z

Overview

MCS1803GS-20-Z from Monolithic Power Systems is a galvanically isolated, linear Hall-effect current sensor optimized for ±20A primary current sensing with 100 mV/A sensitivity, ±2.5% total output error over -40°C to +125°C, and 2.2kVRMS isolation voltage. It operates from a 5V single supply, features differential Hall sensing to reject stray magnetic fields, and integrates a 0.9mΩ primary conductor for low power loss in motor control and SMPS current monitoring.

For engineers reviewing the MCS1803GS-20-Z datasheet, MCS1803GS-20-Z pinout, MCS1803GS-20-Z application, or MCS1803GS-20-Z equivalent, key selection considerations include its SOIC-8 footprint, ratiometric analog output, adjustable bandwidth up to 100kHz via external FILT capacitor, and factory-trimmed accuracy across automotive and industrial temperature ranges.

Technical Context

The MCS1803GS-20-Z implements a differential Hall array with spinning current offset cancellation, enabling stable zero-current output (VCC/2) and <±10 mV offset voltage over temperature. Its internal 0.9mΩ conductor enables direct in-line current measurement without shunt resistors, while galvanic isolation separates primary current path (IP+/IP−) from signal pins (VOUT, FILT, GND, VCC).

Bandwidth is configurable from DC to 100kHz using an external capacitor on FILT, leveraging an internal 1.5kΩ resistor and 1nF capacitor. The device delivers 4µs output rise time, 1.5µs propagation delay, and maintains ratiometry (98–102% KSENS, 99–101% KV0) across 4.5–5.5V supply variation.

Key Specifications

Pinout & Package

Package: SOIC-8 (5mm × 4mm), surface-mount, RoHS-compliant, MSL Level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar linear Hall-effect current sensing applications.

Compared with ACS724LMATR-20AB-T and TLE4971-20B5-U, the MCS1803GS-20-Z uniquely combines 2.2kVRMS safety certification, analog ratiometric output, and user-adjustable bandwidth-making it optimal for isolated analog feedback loops where regulatory compliance and design flexibility are mandatory.

Availability

MCS1803GS-20-Z is available at Aetrix Electronics and suitable for motor control, switch-mode power supplies, and automotive battery monitoring requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MCS1803GS-20-Z 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

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance power management ICs, including DC-DC converters, LED drivers, and precision analog sensors.

The MCS1803 product line delivers isolated current sensing solutions targeting space-constrained, high-reliability applications in automotive, industrial, and computing power systems-emphasizing accuracy, thermal stability, and safety certification.

FAQ

What is the maximum primary current the MCS1803GS-20-Z can safely handle beyond its ±20A range?

The device supports transient currents up to 250A for 10ms (per IEC61000-4-5) and surge currents up to 3000A (8µs/20µs pulse). Continuous operation beyond ±20A increases nonlinearity and total error beyond ±2.5%, though output remains proportional until saturation at VCC–0.5V or 0.5V.

How does the FILT pin affect bandwidth, and what capacitor value yields 20kHz bandwidth?

FILT sets bandwidth via RC filtering with internal 1.5kΩ resistor and 1nF capacitor. For 20kHz, use CF ≈ 530pF (calculated via fBW = 1/(2π × RFi × (CF + CFi))). A 560pF NP0 ceramic capacitor achieves this while maintaining stability across temperature.

Is the MCS1803GS-20-Z AEC-Q100 qualified for automotive use?

While not formally AEC-Q100 certified, the MCS1803GS-20-Z operates reliably from –40°C to +125°C, meets IEC62368-1 isolation standards, and is widely deployed in automotive subsystems such as battery monitors and EPS current feedback-subject to end-customer qualification.

Can the MCS1803GS-20-Z measure bidirectional DC current, and how is polarity indicated?

Yes-it measures ±20A DC with ratiometric output centered at VCC/2. At 0A, VOUT = 2.5V (nominal); positive current raises VOUT above 2.5V (up to 4.5V), negative current lowers it below 2.5V (down to 0.5V), enabling true bidirectional sensing with single-supply ADCs.

What is the impact of primary conductor layout on measurement accuracy?

Accuracy assumes symmetric current flow through both IP+ and IP− pins. Asymmetric PCB traces or external busbar misalignment introduce common-mode magnetic fields that degrade differential rejection. Maintain equal trace width/length and center the conductor under the IC's Hall elements per MPS AN178 guidelines.

Does the MCS1803GS-20-Z require calibration after soldering?

No factory calibration is needed. Offset voltage drift is <±10mV over temperature, and sensitivity error is <±2% across –40°C to +125°C. System-level calibration is optional but not required for applications tolerating ±2.5% total output error.

How does the 0.9mΩ internal conductor affect power dissipation at full scale?

At ±20A, power dissipation is IP² × RP = (20A)² × 0.0009Ω = 0.36W. This results in <10°C junction rise in typical SOIC-8 PCB layouts with 2oz copper, eliminating need for heatsinking in most industrial and automotive applications.