Monolithic Power Systems Inc. MA820GQ-Z

Overview

MA820GQ-Z from Monolithic Power Systems is an 8-bit contactless magnetic angle encoder with ABZ quadrature output and dual magnetic field threshold detection for push/pull button functionality. It delivers absolute angular position via SPI (850–1100 kHz refresh) and incremental ABZ pulses (programmable 1–64 per channel), operating at 3.3 V/12 mA across –40°C to +125°C. Designed for human-machine interface applications such as rotary knobs and manual controls, it replaces potentiometers using a diametrically magnetized cylinder (2–8 mm Ø) with ≤200 rpm rotation.

For engineers reviewing the MA820GQ-Z datasheet, MA820GQ-Z pinout, MA820GQ-Z application, or MA820GQ-Z equivalent, key selection criteria include ABZ pulse programmability, on-chip NVM storage for zero-angle and threshold calibration, integrated MGL/MGH logic outputs for contactless button sensing, and QFN-16 (3×3 mm) package compatibility with end-of-shaft magnet mounting.

Technical Context

The MA820GQ-Z uses Spinaxis™ phase-detection architecture-digitizing magnetic field direction directly via time-to-digital conversion without arctangent computation or feedback loops-enabling open-loop 1 MHz front-end sampling. Its digital conditioning block applies a configurable low-pass filter (Fcutoff = 90 Hz) to achieve 8-bit effective resolution with ≤1.1° INL over full temperature and field range.

ABZ output generation is fully independent of SPI configuration: quadrature A/B channels deliver programmable edge counts per revolution (4–256 edges), while Z-index timing is aligned to B-falling edge and adjustable via ILIP bits. Magnetic field thresholds (MGHT/MGLT) are stored in 3-bit fields of Register 6 and drive dedicated open-drain logic outputs (MGH/MGL) with 6 mT hysteresis and –600 ppm/°C drift.

Key Specifications

Pinout & Package

MA820GQ-Z is housed in a thermally enhanced QFN-16 (3 mm × 3 mm) package with wettable flanks and an exposed center pad recommended for grounding. Pin numbering follows standard top-view orientation (Pin 1 at top-left corner).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AS5048B and TMAG5170, the MA820GQ-Z uniquely integrates ABZ hardware generation, push/pull button logic outputs, and on-chip NVM for zero/threshold storage-reducing firmware overhead and external component count in HMI applications requiring drop-in encoder replacement.

Availability

MA820GQ-Z is available at Aetrix Electronics and suitable for rotary knob control interfaces, automotive HVAC systems, and white goods control panels requiring stable component supply, automotive-grade temperature performance, and contactless position sensing with integrated button functionality.

Supply support for MA820GQ-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 and sensing ICs, with design centers in the US, China, and Taiwan.

The MagAlpha product line delivers contactless magnetic angle sensors optimized for human-machine interface applications-emphasizing ease of integration, programmable flexibility, and robust operation in harsh thermal and mechanical environments.

FAQ

What magnet specifications are required for reliable MA820GQ-Z operation?

The MA820GQ-Z is designed for use with diametrically magnetized cylindrical neodymium magnets (e.g., N35 grade, Ø5 × 3 mm). Minimum field strength is 30 mT at the sensor's sensitive volume; optimal performance occurs between 45–100 mT. Air gap should be ≤1.5 mm, and magnet centering tolerance is ±0.5 mm relative to the package center. Magnet diameter range is 2–8 mm.

How is the zero-angle position programmed and retained?

The zero-angle offset is stored in two 8-bit registers (0x0 and 0x1) as a 16-bit complementary value. Writing to these registers via SPI updates on-chip non-volatile memory, which retains the setting across power cycles. The factory default is 0x0000, corresponding to 360.000° zero position. Programming requires a 16-bit SPI write command followed by 20 ms NVM write delay.

Can the MA820GQ-Z operate without an external microcontroller?

No-the MA820GQ-Z requires an external host MCU to configure registers (zero angle, PPT, thresholds) via SPI and to interpret ABZ pulses or read absolute angle data. It has no autonomous operation mode; all functionality-including ABZ generation and MGH/MGL assertion-is enabled only after proper initialization and parameter loading.

What is the maximum mechanical rotation speed supported by the ABZ output?

The ABZ output supports mechanical speeds up to 100 kRPM when configured for 64 pulses per channel (256 edges/rev), based on its 16 MHz update rate and measured jitter performance. At lower PPT settings (e.g., 1–16), the usable speed increases proportionally-e.g., 1 pulse/channel supports up to 6.4 MRPM-but practical limits are governed by magnet dynamics and mechanical stability, not IC timing.

How does the Spinaxis™ architecture differ from traditional Hall-based angle sensors?

Spinaxis™ uses phase detection of the magnetic field's sinusoidal projection-converting field direction directly into time-domain measurements via a time-to-digital converter-eliminating arctangent computation, lookup tables, or closed-loop interpolators. This yields lower latency (4 ms), higher linearity, and reduced sensitivity to field amplitude variations compared to analog ratiometric or digital interpolation methods.

Is the exposed thermal pad electrically connected internally?

No-the exposed pad on the QFN-16 package is not electrically connected to any internal circuitry. It is recommended to solder it to a grounded copper pour for improved thermal dissipation (θJC = 12°C/W) and mechanical stability, but it may be left floating if thermal constraints permit.

What SPI modes does the MA820GQ-Z support, and how is mode selection handled?

The MA820GQ-Z supports both SPI Mode 0 (CPOL = 0, CPHA = 0) and Mode 3 (CPOL = 1, CPHA = 1). Mode detection is automatic on the first SCLK edge after CS assertion-no configuration register setting is required. The maximum SCLK frequency is 25 MHz; minimum is unrestricted, enabling slow debug interfaces or ultra-low-power polling.