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

Overview

MCS1806GS-3-30-Z from Monolithic Power Systems is a 3.3V single-supply, galvanically isolated Hall-effect current sensor with ±30A 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-3-30-Z datasheet, MCS1806GS-3-30-Z pinout, MCS1806GS-3-30-Z application, or MCS1806GS-3-30-Z equivalent, key selection criteria include its 44mV/A sensitivity at ±30A, SOIC-8 package footprint, 100kHz bandwidth (FILT disconnected), 5µs response time, and 500VRMS working voltage compliance per IEC62368-1.

Technical Context

The MCS1806GS-3-30-Z implements a differential Hall-sensing architecture with two integrated transducers placed asymmetrically along a low-resistance primary conductor, enabling magnetic field difference detection that cancels external interference. Its spinning current technique minimizes offset drift, while internal filter components (RFI = 1.5kΩ, CFI = 1nF) support adjustable bandwidth via external CF capacitor.

Galvanic isolation is achieved through reinforced insulation between primary current terminals (IP+, IP−) and signal pins (VCC, VOUT, FILT, GND), certified to 3000VRMS withstand voltage and 500VRMS working voltage. The device features factory-trimmed sensitivity, ratiometric output scaling (KSENS = 98–102%, KVO = 99–101%), and operates across –40°C to +125°C junction temperature with UVLO threshold of 2.5V.

Key Specifications

Pinout & Package

SOIC-8 package (5mm × 4mm, 1.57mm height) with creepage and clearance ≥4.2mm between primary and secondary sides, supporting reinforced isolation.

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 TMC1100A1DQNT, the MCS1806GS-3-30-Z uniquely balances 3kVRMS isolation, adjustable bandwidth, and SOIC-8 compactness-making it optimal for space-constrained inverters where both safety and dynamic response tuning are required.

Availability

MCS1806GS-3-30-Z is available at Aetrix Electronics and suitable for motor controls, multi-phase inverters, switch-mode power supplies, and over-current fault protection systems requiring stable component supply and long-term lifecycle assurance.

Supply support for MCS1806GS-3-30-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, with emphasis on efficiency, integration, and reliability for industrial, computing, and automotive markets.

The MCS1806 product line delivers isolated current sensing for real-time power system monitoring and protection, designed specifically to replace optocouplers and shunt-based solutions in high-noise, high-isolation applications.

FAQ

What is the maximum continuous primary current the MCS1806GS-3-30-Z can handle without exceeding junction temperature limits?

The device supports ±30A continuous primary current within its specified linear range. At 30A DC, self-heating on a standard 2oz copper evaluation board raises junction temperature by ~45°C above ambient. With TA ≤ 80°C and proper PCB copper area, TJ remains below 125°C-well under the 165°C absolute maximum. Derating is required for pulsed or high-frequency AC currents based on RMS heating.

Can the MCS1806GS-3-30-Z be used with a 5V supply instead of 3.3V?

No-the "-3-" in MCS1806GS-3-30-Z denotes the 3.3V supply variant. Using 5V exceeds the 3.6V absolute maximum supply rating and will damage the device. For 5V operation, select MCS1806GS-5-30-Z, which has different internal trimming and is rated for 4.5–5.5V operation with 66mV/A sensitivity.

How does the FILT pin affect noise performance and bandwidth?

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 lowers bandwidth to ~10kHz and reduces noise to ~15mA(RMS). Leaving FILT open maximizes bandwidth but offers no filtering.

Is the zero-current output voltage (VOUT(Q)) guaranteed to be exactly VCC/2?

VOUT(Q) is nominally VCC/2, with offset voltage (VOE) specified as ±10mV over –40°C to +125°C. At 3.3V supply, this corresponds to ±0.3% full-scale error. The device uses spinning current and factory trimming to minimize thermal drift, ensuring VOE remains stable across temperature and lifetime without recalibration.

Does the MCS1806GS-3-30-Z require external calibration for accuracy?

No-total output error is factory trimmed to ±2.5% across temperature and lifetime, including sensitivity, offset, and nonlinearity. No external calibration is needed for standard applications. However, system-level calibration may improve accuracy to ±0.5% if required for metrology-grade use cases.

What is the minimum recommended copper area for thermal management on the primary conductor pads?

MPS recommends ≥200mm² of 2oz copper per IP+ and IP− pad (combined), connected via multiple thermal vias to inner-layer planes. On the evaluation board, this configuration limits temperature rise to <50°C at 30A DC. Reducing copper area increases self-heating and may trigger thermal shutdown or accelerate parametric drift.

Are the IP+ and IP− pins internally shorted, and can they be used independently?

Yes-pins 1&2 (IP+) and pins 3&4 (IP−) are internally shorted pairs. They must be connected in parallel to carry the full primary current; splitting current between them is not supported. This dual-pin layout improves current-handling capability and reduces inductance compared to single-pin configurations.