The AS5047P is a high-resolution rotary position sensor for high speed (up to 28krpm) angle measurement over a full 360 degree range. This new position sensor is equipped with revolutionary integrated dynamic angle error compensation (DAEC™) with almost 0 latency and offers a robust design that suppresses the influence of any homogenous external stray magnetic field.
A standard 4-wire SPI serial interface allows a host microcontroller to read 14-bit absolute angle position data from the AS5047P and to program non-volatile settings without a dedicated programmer.
Incremental movements are indicated on a set of ABI signals with a maximum resolution of 4000 steps /1000 pulses per revolution in decimal mode and 4096 steps /1024 pulses per revolution in binary mode. The resolution of the ABI signal is programmable and can be reduced to 100 steps per revolution, or 25 pulses per revolution.
Brushless DC (BLDC) motors are controlled through a standard UVW commutation interface with a programmable number of pole pairs from 1 to 7. The absolute angle position is also provided as PWM-encoded output signal.
The AS5047P is a Hall-effect magnetic sensor using a CMOS lateral technology. The lateral Hall sensors convert the magnetic field component perpendicular to the surface of the chip into a voltage.
The signals from the Hall sensors are amplified and filtered by the analog front-end (AFE) before being converted by the analog-to-digital converter (ADC). The output of the ADC is processed by the hardwired CORDIC (coordinate rotating digital computer) block to compute the angle and magnitude of the magnetic vector. The intensity of the magnetic field (magnitude) is used by the automatic gain control (AGC) to adjust the amplification level for compensation of the temperature and magnetic field variations.
The internal 14-bit resolution is available by readout register via the SPI interface. The resolution on the ABI output can be programmed from 4096 to 100 steps per revolution.
The Dynamic Angle Error Compensation block corrects the calculated angle regarding latency, by using a linear prediction calculation algorithm. At constant rotation speed the latency time is internally compensated by the AS5047P, reducing the dynamic angle error at the SPI, ABI and UVW outputs. The AS5047P allows to switch OFF the UVW output interface to display the absolute angle as PWM-encoded signal on the pin W.
At higher speeds, the interpolator fills in missing ABI pulses and generates the UVW signals with no loss of resolution. The non-volatile settings in the AS5047P can be programmed through the SPI interface without any dedicated programmer. The AS5047P is built for high speed application up to 28krpm.