Diodes Incorporated ZMY20TA

Overview

ZMY20TA from Zetex Semiconductors is a magneto-resistive magnetic field sensor in SOT223 package, measuring Hy-field component with 4.7 mV/V sensitivity (typ), 1.7 kΩ bridge resistance (typ), and ±1.0 mV/V offset voltage (VB-referenced) at 25°C; used for non-contact linear position sensing in door interlocks and impeller rotation metering.

For engineers reviewing the ZMY20TA datasheet, ZMY20TA pinout, ZMY20TA application, or ZMY20TA equivalent, key selection criteria include open-circuit sensitivity (3.7–5.7 mV/V/kA/m), hysteresis limit (≤50 µV/V), required bias field Hx = 3 kA/m, operating temperature range (−40 to +150°C), and SOT223 thermal derating above 25°C.

Technical Context

The ZMY20TA implements a thin-film permalloy Wheatstone bridge on silicon, where output voltage scales linearly with orthogonal magnetic field Hy while requiring a stabilizing perpendicular auxiliary field Hx = 3 kA/m. Its operation is insensitive to vertical (H_z) fields.

Bridge resistance (1.2–2.2 kΩ) and offset voltage (±1.0 mV/V) are temperature-stable, with TCR_br = 0.3 %/K and TCV_off = ±3 µV/V/K over −25 to +125°C; maximum supply voltage is 12 V with 120 mW total power dissipation limit.

Key Specifications

Pinout & Package

Package: SOT223 (standard 4-pin thermally enhanced plastic package with exposed tab for heatsinking).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SS495A and KMZ60, the ZMY20TA delivers highest Hy-field sensitivity and widest operating temperature range but requires external Hx magnet and analog signal conditioning - making it optimal for high-precision analog position feedback in harsh thermal environments.

Availability

ZMY20TA is available at Aetrix Electronics and suitable for door interlocks, impeller rotation metering, and engine crankshaft position sensing requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ZMY20TA 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 (now part of Diodes Incorporated) is an ISO 9001/TS16949-certified UK-based analog semiconductor manufacturer focused on high-reliability discrete and sensor solutions.

The ZMY series was developed specifically for contactless, high-sensitivity analog magnetic field measurement in industrial automation and automotive subsystems where thermal stability and repeatability are critical.

FAQ

What auxiliary magnetic field strength is required for stable ZMY20TA operation?

The ZMY20TA requires a fixed perpendicular auxiliary field Hx = 3 kA/m to stabilize the permalloy bridge and suppress hysteresis. This is typically provided by a small permanent magnet placed near the sensor package; deviation beyond ±10% degrades linearity and increases offset drift.

Can ZMY20TA operate without external signal conditioning?

Yes - the ZMY20TA provides a ratiometric differential analog output (+VO/−VO) directly compatible with instrumentation amplifiers or ADC inputs. However, its ±1.0 mV/V offset and 20 mV/V full-scale output require ≥16-bit resolution for sub-degree angular accuracy in position applications.

How does temperature affect ZMY20TA's sensitivity and offset?

Sensitivity drift is −0.3 %/K (TCSV), and offset drift is ±3 µV/V/K (TCVoff), both specified over −25 to +125°C. At 150°C, total offset shift remains within ±0.3 mV/V (vs. 25°C), and sensitivity drops ~30% - requiring calibration compensation in precision systems.

Is the SOT223 package thermally adequate for continuous 120 mW dissipation?

Yes - when mounted on a 40 × 40 mm² PCB with ≥600 mm² copper area, the SOT223 package sustains 120 mW at +125°C ambient. Derating is required above 25°C: VB(max) decreases linearly to 8.5 V at +125°C per the datasheet curve.