Monolithic Power Systems Inc. MA780GQ-P

Overview

MA780GQ-P from Monolithic Power Systems is an 8-bit to 12-bit absolute contactless angle sensor IC that detects angular position of diametrically magnetized permanent magnets via integrated 2D Hall-effect sensing and Spinaxis™ phase-detection architecture. It delivers <0.5µA idle current, supports on-axis and off-axis mounting, and features integrated wake-up angle-change interrupt (ND flag) for battery-powered rotary interfaces.

For engineers reviewing the MA780GQ-P datasheet, MA780GQ-P pinout, MA780GQ-P application, or MA780GQ-P equivalent, this device is selected for ultra-low-power angular measurement in constrained thermal and energy budgets-especially where SPI-configurable resolution (8–12 bit), NVM-stored zero-angle calibration, and ASC power cycling are required.

Technical Context

The MA780GQ-P implements a time-to-digital converter (TDC) front end that digitizes magnetic field direction without arctangent computation or feedback loops, enabling open-loop angle extraction at up to 1.1 MHz internal sampling rate. Its digital conditioning block applies configurable first-order low-pass filtering (τ = 4 µs to 4 ms) to achieve effective resolution from 8 to 12 bits.

Power management is implemented through three distinct modes: continuous Active (10 mA), SPI-accessible Idle (<1.9 µA), and Auto-Sampling Cycle (ASC) with programmable t_ACTIVE and t_CYCLE. The EN and ASC pins enable external control of mode transitions, while the ND and ERR flags provide real-time status for system-level wake-up and fault handling.

Key Specifications

Pinout & Package

MA780GQ-P is housed in a thermally enhanced QFN-16 (3 mm × 3 mm, 0.5 mm pitch) package with exposed thermal pad. Pin 17 (exposed pad) is electrically unconnected but recommended unsoldered for optimal thermal isolation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AS5048B-HTS and TMAG5170-Q1, the MA780GQ-P uniquely integrates ASC power cycling, hardware ND wake-up, and factory-programmable NVM-reducing system-level power, latency, and software development effort for dedicated absolute angle measurement.

Availability

MA780GQ-P is available at Aetrix Electronics and suitable for battery-powered devices, electric power steering systems, and industrial rotary knob interfaces requiring stable component supply, full temperature range qualification, and long-term lifecycle support.

Supply support for MA780GQ-P 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-efficiency power management and sensing solutions for industrial, automotive, and consumer markets.

The MagAlpha® series-including MA780GQ-P-is designed specifically for ultra-low-power, high-accuracy absolute angle measurement in mechanically constrained and energy-sensitive applications.

FAQ

What is the minimum magnetic field strength required for MA780GQ-P to operate within specification?

The MA780GQ-P requires a minimum in-plane magnetic field strength of 30 mT at the sensor's sensitive volume (center of package). Operation below this level may degrade linearity and effective resolution; performance is guaranteed only for fields ≥30 mT, with optimal accuracy at 45–100 mT as specified in electrical characteristics.

Can MA780GQ-P be used in off-axis (side-shaft) mounting configurations?

Yes. The MA780GQ-P supports both end-of-shaft and off-axis mounting. In side-shaft configurations, the sensor measures the XY-plane field angle, and its internal digital conditioning can compensate for non-linear mechanical-to-magnetic angle mapping-enabling accurate recovery of mechanical rotation even with multi-pole magnets.

How does the Auto-Sampling Cycle (ASC) mode reduce average power consumption?

ASC mode alternates between Active (10 mA) and Idle (<0.5 µA) states using an on-chip low-power clock. Average current scales inversely with duty cycle-for example, with t_ACTIVE = 100 µs and t_CYCLE = 100 ms, average current drops to ~10 µA-enabling decade-long battery life in intermittent-use applications.

Is the exposed thermal pad on the QFN-16 package electrically connected?

No. Pin 17 (exposed pad) is electrically unconnected and serves only as a thermal interface. MPS recommends leaving it unsoldered to avoid unintended grounding paths; if soldered, it must connect exclusively to a dedicated thermal pad with no electrical net association.

What SPI modes does MA780GQ-P support, and how is mode selection handled?

The MA780GQ-P supports SPI Mode 0 (CPOL=0, CPHA=0) and Mode 3 (CPOL=1, CPHA=1). Mode detection is automatic on first /CS assertion-no register configuration is needed. Mode 0 is recommended for robustness due to its rising-edge sampling and lower susceptibility to clock jitter in noisy environments.

How is zero-angle calibration stored and restored?

Zero-angle offset and other configuration parameters are stored in on-chip NVM via SPI commands (Store All Registers to NVM). On power-up, values are automatically loaded into registers. Manual restoration is also possible using the Restore All Register Values command-ensuring consistent behavior after reset or brownout events.

Does MA780GQ-P require external components for stable operation?

Yes. A 1 µF ceramic decoupling capacitor must be placed adjacent to VDD with low-inductance path to GND. Additionally, SPI signal integrity requires RC low-pass filters (200 Ω + 10 pF) on SCLK (near sensor), MOSI (near controller), and MISO (near sensor) per layout guidelines in the datasheet.