Monolithic Power Systems Inc. MCS1806GS-5-40-Z

Overview

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

For engineers reviewing the MCS1806GS-5-40-Z datasheet, MCS1806GS-5-40-Z pinout, MCS1806GS-5-40-Z application, or MCS1806GS-5-40-Z equivalent, this page delivers verified specifications, SOIC-8 package layout, real-world use cases in inverters and over-current protection, and validated alternative parts with documented functional differences.

Technical Context

The MCS1806GS-5-40-Z employs a spinning-current technique and differential Hall sensing to cancel offset drift and external magnetic interference. Its internal 0.9mΩ conductor enables low-loss current sampling while maintaining 3kVRMS isolation between primary (IP+/IP−) and signal-side (VCC/VOUT/FILT/GND) terminals.

Bandwidth is adjustable up to 100kHz via external capacitor CF on FILT pin, and output voltage scales ratiometrically with VCC (5V ±10%), ensuring stability across supply variations. Total error remains within ±2.5% across ±40A at TJ = −40°C to +125°C, with factory trimming of sensitivity (50 mV/A) and zero-current offset.

Key Specifications

Pinout & Package

SOIC-8 package (5mm × 4mm, 1.27mm pitch) with creepage/clearance ≥4.2mm for reinforced isolation. Primary current path (IP+/IP−) is fully separated from signal-side pins by internal polyimide barrier.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ACS724LLCTR-40AB-T and TMCS1108A4U, the MCS1806GS-5-40-Z uniquely combines 5V ratiometric operation, user-adjustable bandwidth, and 3kVRMS isolation in an SOIC-8 footprint-enabling tighter control-loop timing and reduced system-level calibration effort in high-reliability industrial drives.

Availability

MCS1806GS-5-40-Z is available at Aetrix Electronics and suitable for motor controls, switch-mode power supplies, and industrial over-current protection requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for MCS1806GS-5-40-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 isolated sensors, with global manufacturing and quality certifications.

The MCS1806 product line delivers compact, high-accuracy isolated current sensing for space-constrained industrial and automotive power systems, emphasizing galvanic isolation integrity, thermal robustness, and factory-trimmed precision without external calibration.

FAQ

What is the maximum continuous primary current the MCS1806GS-5-40-Z can handle without exceeding junction temperature limits?

The device supports ±40A continuous primary current with proper PCB copper area (≥200mm² per side, 2oz copper) and ambient temperature ≤85°C. At 40A, self-heating adds ~35°C to junction above ambient, keeping TJ below 125°C. Derating is required above 85°C ambient or with reduced copper area.

Does the MCS1806GS-5-40-Z require external calibration for accuracy across temperature?

No. The device is factory-trimmed for sensitivity and offset, guaranteeing ±2.5% total output error over −40°C to +125°C without system-level calibration. Offset drift is limited to ±10mV over temperature, and sensitivity error remains within ±2% across the full range.

Can the FILT pin be left unconnected, and what is the default bandwidth?

Yes, FILT can be left floating. In that configuration, the internal 1.5kΩ resistor and 1nF capacitor set a default bandwidth of 100kHz (3dB point), with propagation delay of 1.5µs and response time of 5µs. This mode is recommended for high-speed applications like over-current fault detection.

How does the ratiometric output improve measurement accuracy in noisy power environments?

The ratiometric design ensures both sensitivity (KSENS = 98–102%) and zero-current output (KVO = 99–101%) scale with VCC. When used with the same supply rail feeding the ADC's reference voltage, supply ripple and droop cancel out-reducing measurement error by up to 80% compared to non-ratiometric sensors under ±5% VCC variation.

What is the minimum external component count required for basic operation?

Only one external component is mandatory: a 1µF low-ESR ceramic capacitor from VCC to GND, placed adjacent to the VCC pin. All other functions-including bandwidth setting, filtering, and output loading-are optional or handled internally. No external op-amps, references, or isolation components are needed.

Is the MCS1806GS-5-40-Z qualified for automotive applications?

While not AEC-Q200 qualified, the device operates from −40°C to +125°C, meets IEC62368-1 isolation standards, and is used in automotive on-board chargers and traction inverters. For ASIL-B systems, it requires integration into a broader safety architecture with diagnostic coverage and fault handling per ISO26262.