Monolithic Power Systems Inc. MCS1803GS-05-P

Overview

MCS1803GS-05-P from Monolithic Power Systems is a galvanically isolated, linear Hall-effect current sensor optimized for ±5A DC/AC sensing with 400 mV/A sensitivity, ±2.5% total output error over -40°C to +125°C, and 2.2kVRMS isolation voltage-used in motor control feedback loops and over-current protection circuits where compact SOIC-8 footprint and magnetic field immunity are critical.

For engineers reviewing the MCS1803GS-05-P datasheet, MCS1803GS-05-P pinout, MCS1803GS-05-P application, or MCS1803GS-05-P equivalent, key selection criteria include primary conductor resistance (0.9 mΩ), ratiometric 5V output scaling, adjustable bandwidth up to 100 kHz via FILT pin capacitor, and factory-trimmed offset stability across temperature.

Technical Context

The device implements differential Hall sensing with spinning current offset cancellation to reject stray magnetic fields and achieve ±2.5% accuracy over full temperature range. Its integrated primary conductor enables direct current path integration while maintaining galvanic isolation between IP+ / IP− and signal pins (VOUT, FILT, GND, VCC).

Internal architecture includes a POR-regulated 5V supply chain, dynamic offset cancellation loop, temperature-compensated Hall driver, and programmable filter network (RFi = 1.5 kΩ, CFi = 1 nF) that allows external bandwidth tuning via capacitor on FILT pin-enabling tradeoffs between noise (50 mA(RMS) at 60 kHz) and response time (4 µs rise time).

Key Specifications

Pinout & Package

Package: SOIC-8 (5 mm × 4 mm), 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 ACS712ELCTR-05B-T, MCS1803GS-05-P delivers superior magnetic immunity and tighter accuracy; versus TLE4971-5U, it offers simpler layout (no diagnostic routing) and lower component count, though without safety flags.

Availability

MCS1803GS-05-P is available at Aetrix Electronics and suitable for motor control feedback, automotive battery monitoring, and SMPS over-current protection requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for MCS1803GS-05-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 MCS1803 product line targets isolated current sensing in industrial motor drives, automotive electrification, and renewable energy systems-designed to replace optocouplers and discrete shunt-based solutions with integrated, calibrated, and safety-certified alternatives.

FAQ

What is the minimum recommended bypass capacitor for VCC?

A 1 µF low-ESR ceramic capacitor must be placed as close as possible to the VCC pin (Pin 8) to suppress high-frequency switching noise and ensure stable internal regulation. Larger values (e.g., 10 µF tantalum in parallel) improve low-frequency ripple suppression but do not replace the mandatory 1 µF ceramic.

Can MCS1803GS-05-P measure AC current waveforms accurately?

Yes-the device provides true linear response to both AC and DC currents within its ±5A range, with 100 kHz bandwidth and <5 µs response time. Its differential Hall architecture rejects common-mode magnetic interference, making it suitable for measuring distorted or high-frequency AC waveforms in inverters and UPS systems.

How does the FILT pin affect noise performance?

Connecting a capacitor (CF) between FILT (Pin 6) and GND (Pin 5) forms a first-order RC filter with internal RFi (1.5 kΩ) and CFi (1 nF), reducing bandwidth and input-referred noise. With 1 nF CF, noise drops to 50 mA(RMS); with no capacitor, bandwidth reaches 100 kHz and noise increases to 200 µA(RMS)/√Hz.

What is the maximum continuous primary current before thermal derating?

At ambient 85°C, the 0.9 mΩ conductor resistance causes ~225 mW dissipation at ±5A, resulting in <10°C junction rise. The device remains within its 165°C max junction rating up to +125°C ambient, so no derating is required for continuous ±5A operation across the full -40°C to +125°C case temperature range.

Is the output truly ratiometric across supply variation?

Yes-both sensitivity (KSENS = 98–102%) and zero-current output (KVO = 99–101%) scale with VCC from 4.5 V to 5.5 V. This ensures consistent gain and offset tracking when used with an MCU's same-supply ADC reference, eliminating ratio-metric error in closed-loop control systems.

Does the device require calibration during system assembly?

No-factory trimming achieves ±2.5% total output error over temperature without user calibration. Offset voltage is stabilized via spinning current technique, and sensitivity is laser-trimmed. Only system-level gain/offset correction is needed if absolute accuracy better than ±2.5% is required.

What safety certifications apply to the isolation barrier?

The isolation barrier is type-tested to IEC62368-1 for 2.2 kVRMS withstand voltage and 100% production tested per the same standard. It meets basic insulation requirements for 250 VRMS working voltage and supports reinforced insulation architectures when combined with external creepage/clearance design.