Monolithic Power Systems Inc. MCS1802GS-30-P

Overview

MCS1802GS-30-P from Monolithic Power Systems is a galvanically isolated, linear Hall-effect current sensor optimized for ±30A bidirectional DC/AC current measurement with ±2.5% total output error over -40°C to +125°C. It operates from a 3.3V supply, features 0.9mΩ internal conductor resistance, 2.2kVRMS isolation, and ratiometric analog output proportional to primary current. It replaces optocouplers in motor control and power supply over-current protection circuits.

For engineers reviewing the MCS1802GS-30-P datasheet, MCS1802GS-30-P pinout, MCS1802GS-30-P application, or MCS1802GS-30-P equivalent, key selection criteria include its SOIC-8 package with integrated 30A-rated primary path, differential Hall sensing for stray-field immunity, adjustable bandwidth up to 100kHz via external FILT capacitor, and factory-trimmed sensitivity of 44mV/A.

Technical Context

The MCS1802GS-30-P implements a differential Hall array with spinning current offset cancellation to suppress thermal drift and external magnetic interference. Its primary conductor (IP+/IP−) forms a low-resistance current path (0.9mΩ), while two spatially separated Hall transducers measure the resulting magnetic field gradient-converted to voltage via precision analog signal chain including dynamic offset correction and temperature-compensated gain.

Galvanic isolation is achieved through internal package construction: the IP+ and IP− pins are electrically isolated from VCC, VOUT, FILT, and GND signal pins, rated at 2.2kVRMS withstand voltage per IEC62368-1. Bandwidth is programmable from ~10kHz to 100kHz by connecting an external capacitor (CF) between FILT and GND, leveraging internal 1.5kΩ filter resistance and 1nF capacitance.

Key Specifications

Pinout & Package

Package: SOIC-8 (5mm × 4mm), surface-mount, with primary current terminals (IP+, IP−) physically separated from signal pins for reinforced isolation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ACS724LLCTR-30AB-T and TLE4971-25S4-10-1-500, the MCS1802GS-30-P delivers optimal integration for space-constrained 3.3V systems needing ±30A measurement, combining SOIC-8 size, 0.9mΩ conductor loss, and guaranteed ±2.5% accuracy without external calibration.

Availability

MCS1802GS-30-P is available at Aetrix Electronics and suitable for motor control, switch-mode power supplies, and automotive battery monitoring requiring stable component supply, long-lifecycle support, and RoHS-compliant sourcing.

Supply support for MCS1802GS-30-P 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 MCS1802 series targets isolated current sensing in compact, high-efficiency power systems-designed to replace optocouplers and discrete shunt-based solutions with integrated galvanic isolation and factory-calibrated accuracy.

FAQ

What is the maximum continuous primary current the MCS1802GS-30-P can handle without derating?

The device is rated for ±30A continuous primary current with full accuracy specifications. At 30A, power dissipation is 0.9mΩ × (30A)² = 0.81W. With SOIC-8 thermal resistance (θJA ≈ 120°C/W), junction rise is ~97°C above ambient-well within the -40°C to +125°C operating range if board layout provides adequate copper area for heat spreading.

How does the FILT pin affect noise performance and bandwidth trade-off?

Connecting a capacitor (CF) between FILT and GND sets the 3dB bandwidth per fBW = 1/(2π × 1.5kΩ × (CF + 1nF)). A 1nF CF yields ~100kHz bandwidth and ~50mA(RMS) input-referred noise; increasing CF to 10nF lowers bandwidth to ~10kHz and reduces noise to ~16mA(RMS), enabling cleaner measurements in noisy environments.

Can the MCS1802GS-30-P measure AC current waveforms accurately at 50/60Hz?

Yes. With FILT unconnected (default 100kHz bandwidth), the device supports full-scale sinusoidal AC measurement up to 50kHz. At 60Hz, phase delay is negligible (<0.1°), and total error remains within ±2.5% across temperature, making it suitable for energy metering, grid-tie inverters, and UPS monitoring.

Is external filtering required on the VOUT pin for ADC interfacing?

No external RC filter is required for basic ADC sampling. The output drives a minimum 4.7kΩ load and has 10nF capacitive load tolerance. For high-resolution (≥16-bit) ADCs, a simple 10Ω series resistor + 100nF capacitor to GND at the ADC input suppresses high-frequency noise without affecting DC accuracy or bandwidth.

What is the meaning of "ratiometric output" and how does it benefit system design?

Ratiometric output means both sensitivity (mV/A) and zero-current output (VCC/2) scale linearly with VCC. If VCC varies from 3.0V to 3.6V, VOUT(Q) shifts from 1.50V to 1.80V and sensitivity changes proportionally-enabling use of the same VCC rail for both sensor supply and ADC reference, eliminating ratio errors from independent voltage sources.

Does the MCS1802GS-30-P require calibration during production?

No. The device is factory-trimmed for sensitivity and offset, delivering ±2.5% total output error over temperature without end-user calibration. System-level calibration is optional for applications demanding <1% error, but not required for motor control, PSU OCP, or battery monitoring per typical industrial specs.

How is galvanic isolation verified in production?

Every unit undergoes 100% production testing per IEC62368-1 for 2.2kVRMS withstand isolation voltage at 60 seconds. Additionally, dielectric surge strength is validated at 6kV (1.2/50µs waveform) during qualification-ensuring robustness against transient overvoltages in industrial and automotive environments.