Diodes Incorporated ZMC20

Overview

ZMC20 from Zetex Semiconductors is a galvanically isolated current sensor IC using magnetoresistive thin-film permalloy to measure DC or AC current up to 20 A with 12 V supply, 0.7 mΩ internal conductor resistance, and 100 kHz bandwidth-used in motor drive current feedback loops.

For engineers reviewing the ZMC20 datasheet, ZMC20 pinout, ZMC20 application, or ZMC20 equivalent, key selection criteria include isolation voltage (2 kV), open-circuit sensitivity (0.25 mV/V/A), offset voltage (±2 mV/V), operating temperature range (–40 to +120 °C), and mod. DIL-14 package compatibility with PCB-mount current-sensing layouts.

Technical Context

The ZMC20 integrates a magnetoresistive bridge on a silicon die positioned adjacent to an internal copper current path; magnetic field from conductor current induces proportional resistance change in the permalloy film, converted to differential output voltage without external excitation field.

It delivers galvanic isolation via internal insulation between primary current path (pins 8–10 / 11–13) and secondary signal circuit (pins 3, 4, 5, 6); operates from 12 V supply with no auxiliary bias required, and supports transient overloads of 300 A for 10 ms at 20 °C ambient.

Key Specifications

Pinout & Package

Package: modified DIL-14 (dual-in-line, 14-pin, through-hole, 2.54 mm pitch, internal isolation barrier).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ACS712ELC-20A and TBMA100-20, the ZMC20 uniquely combines 12 V single-supply operation, integrated low-resistance conductor, and magnetoresistive stability-making it optimal for embedded motor drives and PSU current loops where PCB area, supply simplicity, and thermal drift tolerance are prioritized.

Availability

ZMC20 is available at Aetrix Electronics and suitable for motor drive current feedback, switching power supply monitoring, solar inverter DC link sensing, and industrial PLC analog input modules requiring stable component supply across extended temperature and isolation-critical environments.

Supply support for ZMC20 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

Zetex Semiconductors plc was a UK-based analog and discrete semiconductor manufacturer specializing in high-performance, application-optimized devices before its acquisition by Diodes Incorporated in 2008.

The ZMC series was designed specifically for isolated, contactless current measurement in industrial power electronics-emphasizing integration, reliability, and ease of PCB implementation without external magnetics.

FAQ

What is the maximum continuous current the ZMC20 can measure?

The ZMC20 is rated for continuous measurable current of ±20 A DC or AC RMS. Its internal copper conductor has 0.7 mΩ resistance, resulting in ≤2.8 W power dissipation at 20 A, which remains within thermal limits at Tamb ≤ +85 °C with standard PCB copper pour. Derating is recommended above 85 °C ambient.

Does the ZMC20 require external calibration or trimming?

No external calibration is required. The device features factory-trimmed bridge offset (±2 mV/V) and sensitivity (0.25 mV/V/A). Users may apply one-point system-level offset correction in software if needed, but no hardware trim components or external references are necessary for typical industrial applications.

Can the ZMC20 be used for bidirectional current sensing?

Yes. The ZMC20 provides a differential output voltage (VO = V3 − V5) that reverses polarity with current direction. At 12 V supply, +20 A yields +6 mV output, and –20 A yields –6 mV output-enabling true bidirectional measurement with a single-ended or differential ADC capable of reading both polarities.

How is galvanic isolation achieved in the ZMC20?

Isolation is achieved via internal molded insulation between the primary current path (pins 8–10 and 11–13) and the secondary signal circuit (pins 3, 4, 5, 6). This reinforced insulation barrier is rated for 2 kV RMS, verified per IEC 60950, and does not rely on air gaps or external potting-ensuring consistent creepage/clearance in automated assembly.