Monolithic Power Systems Inc. MCS1803GS-05-Z

Overview

MCS1803GS-05-Z from Monolithic Power Systems is a galvanically isolated, linear Hall-effect current sensor optimized for ±5A DC/AC sensing with 400 mV/A sensitivity, ±2.5% total output error over -40°C to +125°C, and 2.2kVRMS isolation voltage. It replaces optocouplers in motor control feedback loops where compact size, magnetic immunity, and ratiometric analog output are required.

For engineers reviewing the MCS1803GS-05-Z datasheet, MCS1803GS-05-Z pinout, MCS1803GS-05-Z application, or MCS1803GS-05-Z equivalent, key selection criteria include primary conductor resistance (0.9 mΩ), adjustable bandwidth (up to 100 kHz), 4 µs output rise time, and SOIC-8 footprint compatibility with space-constrained PCB layouts.

Technical Context

The device integrates a differential Hall array with spinning current offset cancellation to reject stray magnetic fields and achieve stable zero-current output (VCC/2 ±15 mV). Its internal primary conductor path (pins 1–4) is galvanically isolated from signal pins (5–8), enabling high-voltage system monitoring without external isolation components.

Bandwidth is set via external capacitor CF on FILT pin, interacting with internal 1.5 kΩ resistor and 1 nF capacitor to form a programmable low-pass filter. The ratiometric architecture ensures output scaling with VCC (98–102% KSENS, 99–101% KVO), supporting supply variations from 4.5 V to 5.5 V.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar linear Hall-effect current sensing applications.

Compared with ACS712ELCTR-05B-T and TLE4971-5U, the MCS1803GS-05-Z delivers superior thermal stability, configurable bandwidth, and lower conduction loss-making it optimal for high-reliability analog feedback in motor drives and industrial power supplies.

Availability

MCS1803GS-05-Z is available at Aetrix Electronics and suitable for motor control feedback, automotive battery monitoring, industrial SMPS protection, and energy metering applications requiring stable component supply, long-lifecycle support, and guaranteed traceable sourcing.

Supply support for MCS1803GS-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 MCS1803 product line delivers isolated current sensing solutions for demanding industrial, automotive, and renewable energy systems-designed to replace optocouplers and shunt-based architectures with integrated, calibrated, and thermally robust alternatives.

FAQ

What is the maximum continuous primary current the MCS1803GS-05-Z can handle without damage?

The device supports continuous primary currents up to ±5 A within its specified accuracy range. While the conductor can tolerate higher peak currents (e.g., 250 A transient per IEC61000-4-5), sustained operation beyond ±5 A increases nonlinearity and total error beyond ±2.5%. Junction temperature must remain ≤165°C, limiting practical continuous current based on PCB copper area and ambient conditions.

How does the FILT pin affect bandwidth and noise performance?

Connecting an external capacitor (CF) between FILT and GND forms a first-order RC filter with internal 1.5 kΩ resistance and 1 nF capacitance. A 10 nF CF reduces bandwidth to ~10 kHz, lowering output noise (e.g., 50 mA RMS at 60 kHz) but increasing response time. With FILT open, bandwidth reaches 100 kHz and rise time remains 4 µs-ideal for dynamic current tracking.

Is the MCS1803GS-05-Z compatible with 3.3 V microcontrollers?

No-the device requires a 4.5 V to 5.5 V supply and produces a ratiometric output centered at VCC/2. At VCC = 5 V, VOUT spans ~0.5 V to 4.5 V for ±5 A. Direct interfacing with 3.3 V ADCs requires level-shifting or attenuation; however, its 4.7 kΩ minimum output load tolerance allows use with standard op-amp buffers for voltage scaling.

Does the SOIC-8 package provide sufficient creepage for 300 V AC working voltage?

Yes-external creepage and clearance are both 4.2 mm, exceeding IEC62368-1 requirements for basic insulation at 300 V AC (minimum 2.5 mm). The 2.2 kVRMS withstand rating and 350 VPK working voltage rating confirm suitability for reinforced isolation in 230 V AC input stages and 400 V DC bus monitoring.

Can multiple MCS1803GS-05-Z devices share a common GND connection?

Yes-GND (pin 5) is the signal reference for the Hall sensor and amplifier circuitry and must be connected to the controller-side ground plane. The primary conductor path (pins 1–4) is fully isolated, so multiple units can monitor different branches while sharing one signal GND, provided star grounding and separation from noisy power grounds are maintained.

What is the impact of conductor self-heating on measurement accuracy?

At ±5 A, 0.9 mΩ resistance generates 22.5 mW of heat. In a standard 2 oz copper SOIC-8 layout, this raises die temperature by <2°C-well within the ±2.5% total error specification. Accuracy degradation from self-heating becomes significant only above ±20 A; for high-current variants (e.g., MCS1803GS-50), thermal design guidance is provided in MPS AN178.

How is the ±2.5% total output error distributed across temperature and current range?

At ±5 A and -40°C to +125°C, ±2.5% includes ±1.5% sensitivity error and ±15 mV offset voltage (±3.75% of full-scale 400 mV). At 0 A, error is dominated by offset; at ±5 A, sensitivity error dominates. Lifetime drift adds ±1% to both components, confirmed by accelerated aging tests per JEDEC JESD22-A108.