Monolithic Power Systems Inc. MCS1806GS-3-05-Z

Overview

MCS1806GS-3-05-Z from Monolithic Power Systems is a 3.3V single-supply, galvanically isolated Hall-effect current sensor with ±5A bidirectional sensing range, ±2.5% total output error over -40°C to +125°C, and 3kVRMS isolation rating. It integrates a 0.9mΩ primary conductor and differential Hall array for stray-field immunity, delivering ratiometric analog output proportional to AC/DC current in motor control, inverter, and over-current protection circuits.

For engineers reviewing the MCS1806GS-3-05-Z datasheet, MCS1806GS-3-05-Z pinout, MCS1806GS-3-05-Z application, or MCS1806GS-3-05-Z equivalent, key selection criteria include its SOIC-8 package footprint, 264 mV/A sensitivity at ±5A, 100kHz bandwidth (FILT open), 90µs power-on time, and 500VRMS working voltage compliance per IEC62368-1.

Technical Context

The MCS1806GS-3-05-Z implements a differential Hall-sensing architecture with two physically separated transducers (PMCF1 = 0.6 mT/A, PMCF2 = 0.3 mT/A) to reject common-mode magnetic interference. Its spinning current technique minimizes offset drift, achieving ±5 mV zero-current offset over -40°C to +25°C.

Galvanic isolation is achieved via reinforced insulation across the primary conductor (IP+/IP−) and signal side (VCC/VOUT/FILT/GND), rated for 3kVRMS withstand and 500VRMS continuous working voltage. Bandwidth is adjustable up to 100kHz using an external capacitor on FILT, with internal RFI = 1.5kΩ and CFI = 1nF forming a programmable low-pass filter.

Key Specifications

Pinout & Package

Package: SOIC-8 (5mm × 4mm, 1.27mm pitch), surface-mount, RoHS-compliant, MSL Level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar isolated current sensing applications.

Compared with ACS712ELCTR-5B-T and TMCS1100A1QDR, the MCS1806GS-3-05-Z uniquely combines 3.3V operation, SOIC-8 footprint, user-adjustable bandwidth, and ±2.5% error over full automotive temperature range-making it optimal for cost-sensitive, space-constrained, and thermally demanding motor control designs.

Availability

MCS1806GS-3-05-Z is available at Aetrix Electronics and suitable for motor control, inverter phase monitoring, and over-current protection requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for MCS1806GS-3-05-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 MCS1806 product line delivers isolated current sensing for industrial motor drives, renewable energy inverters, and automotive subsystems-designed to replace optocouplers with higher accuracy, lower drift, and smaller footprint.

FAQ

What is the maximum continuous primary current the MCS1806GS-3-05-Z can handle without exceeding junction temperature limits?

The device supports ±5A continuous primary current within its optimized accuracy range. At 25°C ambient and on a standard evaluation board, self-heating remains below 20°C rise at ±5A DC. For higher currents or elevated ambient temperatures, thermal derating must follow the data in Figure 10 of the datasheet, ensuring junction temperature stays ≤125°C for guaranteed performance and ≤165°C absolute maximum.

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

Connecting a capacitor (CF) between FILT and GND forms a first-order RC filter with internal RFI = 1.5kΩ and CFI = 1nF. A 1nF CF yields ~100kHz bandwidth and ~50mA(RMS) input-referred noise; increasing CF to 10nF reduces bandwidth to ~10kHz and noise to ~16mA(RMS). This allows designers to optimize for either dynamic response or noise rejection based on application requirements.

Can the MCS1806GS-3-05-Z be used with a 5V supply?

No-the GS-3 suffix denotes the 3.3V supply variant. Using 5V on VCC exceeds the absolute maximum rating of 3.6V and will damage the device. For 5V operation, select MCS1806GS-5-05-Z (400 mV/A sensitivity, ±5A range) or other GS-5-x variants listed in the ordering table.

What is the significance of the "Z" suffix in MCS1806GS-3-05-Z?

The "Z" suffix indicates tape-and-reel packaging per JEDEC standard: 2500 units per reel, compatible with automated SMT placement equipment. It does not affect electrical specifications or performance-only packaging format and logistics handling.

Does the MCS1806GS-3-05-Z require external calibration for production use?

No-factory trimming ensures ±2% sensitivity error and ±5 mV offset over -40°C to +25°C, meeting ±2.5% total output error without system-level calibration. However, for applications demanding <1% error, a one-point zero-current offset correction at system level is recommended to cancel board-level thermal gradients.

How is isolation verified during manufacturing?

Every unit undergoes 100% production testing per IEC62368-1 for 3000VRMS withstand isolation voltage at 60 seconds. Additionally, dielectric surge strength is validated per IEC61000-4-5 (6kV, 5 pulses), and external clearance/creepage is measured at ≥4.2mm between IP and signal pins to ensure reinforced insulation integrity.

What PCB layout practices maximize accuracy and thermal performance?

Follow MPS guidelines: use ≥2oz copper on primary current paths (IP+/IP−), isolate signal traces from high-current loops, place 1µF VCC bypass capacitor within 2mm of pin 8, and avoid routing sensitive traces (VOUT, FILT) near switching nodes. Thermal vias under the exposed pad (if present) and extended copper pour under the SOIC-8 body improve heat dissipation.