Monolithic Power Systems Inc. MCS1806GS-3-30-P

Overview

MCS1806GS-3-30-P from Monolithic Power Systems is a galvanically isolated, linear Hall-effect current sensor optimized for ±30A bidirectional DC/AC sensing with 3.3V single-supply operation, 44 mV/A sensitivity, ±2.5% total output error over -40°C to +125°C, and 3kVRMS isolation - deployed in motor control feedback loops and inverter phase-leg monitoring where compact SOIC-8 footprint and magnetic immunity are critical.

For engineers reviewing the MCS1806GS-3-30-P datasheet, MCS1806GS-3-30-P pinout, MCS1806GS-3-30-P application, or MCS1806GS-3-30-P equivalent, key selection criteria include primary conductor resistance (0.9 mΩ), adjustable bandwidth up to 100 kHz via FILT pin capacitor, ratiometric output scaling with VCC, differential Hall array rejection of stray fields, and compliance with IEC62368-1 basic isolation at 500 VRMS working voltage.

Technical Context

The device integrates two matched Hall plates placed asymmetrically along a low-resistance primary conductor to generate differential magnetic field sensing - enabling cancellation of common-mode external fields and eliminating magnetic hysteresis. Its spinning current offset cancellation technique achieves stable zero-current output (VOUT(Q) = VCC/2) with ±10 mV offset drift over temperature.

Isolation is achieved via reinforced dielectric barrier between primary current path (IP+/IP−) and signal side (VCC/VOUT/FILT/GND), rated for 3kVRMS surge and 500 VRMS continuous working voltage per IEC62368-1. Bandwidth is programmable from <10 kHz to 100 kHz using an external capacitor on the FILT pin, leveraging internal RFI = 1.5 kΩ and CFI = 1 nF filter network.

Key Specifications

Pinout & Package

SOIC-8 package (5 mm × 4 mm, 1.5 mm height) with reinforced creepage/clearance; primary current path (IP+/IP−) electrically and physically isolated from signal-side pins (VCC, VOUT, FILT, GND).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ACS724LLCTR-30AB-T and TMC1100A10XATMA1, the MCS1806GS-3-30-P delivers superior isolation robustness (3kVRMS vs. 2.5/5kVRMS), analog simplicity, and bandwidth configurability - making it optimal for cost-sensitive, high-reliability analog-control systems requiring minimal external components and proven field performance in motor drives.

Availability

MCS1806GS-3-30-P is available at Aetrix Electronics and suitable for motor controls, switch-mode power supplies, and automotive onboard chargers requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for MCS1806GS-3-30-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, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MCS1806 product line targets high-accuracy, isolated current sensing in space-constrained industrial and automotive power systems - emphasizing low-loss conduction, magnetic immunity, and simplified system integration without external amplification or isolation components.

FAQ

What is the maximum continuous primary current the MCS1806GS-3-30-P can handle without exceeding its thermal limits?

The device is rated for ±30A full-scale linear operation, but its absolute maximum primary current depends on PCB thermal design. With 0.9 mΩ conductor resistance and 10 cm² of 2 oz copper on inner layers, sustained 30A DC causes ~1.5°C/W rise; junction temperature stays below 125°C at ambient ≤85°C. Derating is required above 85°C ambient or with reduced copper area.

Does the MCS1806GS-3-30-P require external calibration for accuracy across temperature?

No. The device is factory-trimmed for sensitivity and offset, achieving ±2.5% total output error over -40°C to +125°C without user calibration. Offset drift is limited to ±10 mV, and sensitivity error remains within ±2% across temperature - verified per production test flow per IEC62368-1.

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

Yes, the FILT pin may be left floating to achieve maximum bandwidth of 100 kHz. In this configuration, propagation delay is 1.5 µs and response time is 5 µs. Floating FILT disables the internal RC filter, so noise performance degrades - use only when high-speed transient capture is prioritized over noise rejection.

How does the ratiometric output improve system-level accuracy in variable-supply environments?

The ratiometric architecture ensures both zero-current output (VCC/2) and sensitivity scale linearly with VCC. If the MCU's ADC reference matches VCC, gain and offset errors from supply variation cancel - reducing total system error by up to 40% compared to fixed-reference architectures, especially in 3.3V systems with ±5% rail tolerance.

Is the MCS1806GS-3-30-P certified for reinforced insulation per IEC62368-1?

Yes. It is agency-type-tested to 3000 VRMS for 60 seconds per IEC62368-1 Annex G and 100% production-tested per the same standard. External clearance and creepage are both 4.2 mm, satisfying reinforced insulation requirements for mains-connected equipment up to 500 VRMS working voltage.

What is the recommended bypass capacitor for the VCC pin, and where should it be placed?

A 1 µF low-ESR ceramic capacitor (X7R, 0603 or larger) must be placed between VCC and GND, with traces shorter than 2 mm and vias adjacent to the pins. This minimizes high-frequency noise coupling into the Hall sensor core and prevents oscillation during fast load transients in motor drive applications.

Does the device support bidirectional current measurement, and how is polarity indicated?

Yes. The output is centered at VCC/2 (e.g., 1.65 V at 3.3V supply): currents from −30A to 0A produce outputs from 0.3 V to 1.65 V, and +30A yields 3.0 V. Polarity is inherently encoded in the analog voltage level - no digital interface or polarity pin is needed, simplifying analog front-end design.