Monolithic Power Systems Inc. MCS1806GS-5-20-Z

Overview

MCS1806GS-5-20-Z from Monolithic Power Systems is a galvanically isolated, linear Hall-effect current sensor optimized for ±20A bidirectional DC/AC sensing with 5V supply, 100mV/A sensitivity, ±2.5% total output error, and 3kVRMS isolation. It integrates low-resistance (0.9mΩ) primary conductors and differential Hall sensing to reject stray magnetic fields, enabling precise current monitoring in high-noise motor control and power conversion circuits.

For engineers reviewing the MCS1806GS-5-20-Z datasheet, MCS1806GS-5-20-Z pinout, MCS1806GS-5-20-Z application, or MCS1806GS-5-20-Z equivalent, this device delivers ratiometric analog output, adjustable bandwidth up to 100kHz, factory-trimmed accuracy, and SOIC-8 footprint compatibility-critical for space-constrained industrial inverters and over-current protection designs.

Technical Context

The MCS1806GS-5-20-Z employs a differential Hall array with spinning current offset cancellation to achieve stable zero-current output (VCC/2 ±10mV) and eliminate magnetic hysteresis. Its internal 1.5kΩ filter resistor and 1nF capacitor enable bandwidth tuning via external CF, supporting noise-bandwidth tradeoffs from <10kHz to 100kHz.

Galvanic isolation is implemented via reinforced insulation across the SOIC-8 package, delivering 3kVRMS dielectric strength and 500VRMS working voltage per IEC62368-1, with 4.2mm creepage/clearance between primary (IP+/IP−) and signal (VCC/VOUT/FILT/GND) terminals.

Key Specifications

Pinout & Package

SOIC-8 package (5mm × 4mm, 1.55mm height) with reinforced creepage/clearance for isolation compliance. Primary current path (IP+/IP−) and signal pins are physically separated on opposite sides of the package body.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ACS724LLCTR-20AB-T and TB9051FTG, the MCS1806GS-5-20-Z uniquely combines 3kVRMS isolation, differential Hall field immunity, and FILT-adjustable bandwidth-enabling robust, standards-compliant current sensing in high-reliability power electronics where safety, noise, and dynamic response are co-constrained.

Availability

MCS1806GS-5-20-Z is available at Aetrix Electronics and suitable for motor controls, switch-mode power supplies, automotive onboard chargers, and industrial over-current protection requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for MCS1806GS-5-20-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 over two decades of innovation in DC/DC converters, motor drivers, and precision analog sensors.

The MCS1806 product line was designed specifically for isolated current sensing in space-constrained, high-efficiency power systems-emphasizing low conductor loss, magnetic immunity, and seamless integration into 5V and 3.3V control domains.

FAQ

What is the maximum continuous primary current the MCS1806GS-5-20-Z can handle without exceeding junction temperature limits?

The device supports ±20A continuous primary current within its specified accuracy range. At 20A, self-heating on a standard evaluation board raises junction temperature by ~35°C above ambient. With TA ≤ 90°C and adequate PCB copper area (≥200mm² 2oz copper), the 165°C max junction temperature is not exceeded-enabling reliable operation in enclosed industrial enclosures.

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 reduces bandwidth to ~10kHz and noise to ~15mA(RMS), enabling cleaner measurements in low-frequency motor control applications.

Can the MCS1806GS-5-20-Z be used with a 3.3V supply?

No. The "-5-" suffix denotes 5V supply optimization. Using 3.3V violates the minimum 4.5V operating condition and will trigger UVLO, disabling output. For 3.3V systems, select MCS1806GS-3-20-Z (100mV/A sensitivity, ±20A range, 3.3V supply).

What is the meaning of "±2.5% total output error" and how is it distributed across operating conditions?

This specification includes combined effects of sensitivity error (±2%), offset voltage (±10mV), nonlinearity (±0.5%), and lifetime drift (±1%). At ±20A and TJ = 25°C to 125°C, worst-case error is ±2.5%; at room temperature and mid-scale current, typical error is ±1.2%. Error is dominated by offset near zero current and sensitivity error near full scale.

Is the primary conductor internally fused or rated for short-circuit survival?

The primary conductor is not fused but rated for 3000A surge (8µs/20µs waveform per IEC61000-4-5) and 250A transient (10ms single peak). Its 0.9mΩ resistance limits fault energy, and the SOIC-8 package withstands >260°C soldering temperatures-supporting robust operation in fault-prone power systems without external fusing in many designs.

Does the MCS1806GS-5-20-Z require calibration during system production?

No factory calibration is needed beyond initial zero-current trim. The device ships with ±2.5% total output error guaranteed across temperature and lifetime. System-level calibration is optional and typically applied only for applications demanding <±0.5% absolute accuracy, using the ratiometric output and known reference current.

How does the differential Hall architecture improve performance versus single-point Hall sensors?

By measuring magnetic field difference between two spatially separated Hall plates, the MCS1806GS-5-20-Z cancels uniform external fields (e.g., from adjacent busbars or transformers) while preserving gradient-based signal from the primary conductor. This eliminates need for magnetic shielding and improves accuracy in dense power layouts where single-point sensors suffer >5% error from stray fields.