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AS5048A/AS5048B

Magnetic Rotary Encoder

14-bit Angular Position Sensor

Datasheet

3

Functional Description

The AS5048 is a magnetic Hall sensor system manufactured in a CMOS process. A lateral Hall sensor array is used to measure

the magnetic field components perpendicular to the surface of the chip. The AS5048 is uses self-calibration methods to

eliminate signal offset and sensitivity drifts.

The integrated Hall sensors are placed around the center of the device and deliver a voltage representation of the magnetic flux

Bz.

Through Sigma-Delta Analog-to-Digital Converter (ADC) and Digital Signal-Processing (DSP) algorithms, the AS5048 provides

accurate high-resolution absolute angular position information. This is accomplished by a Coordinate Rotation Digital Computer

(CORDIC) calculates the angle and the magnitude of the Hall array signals.

The DSP is also used to provide digital information at the outputs that indicate movements of the magnet towards or away from

the device’s surface, in the z-axis.

A small diametrically magnetized (two-pole) standard magnet provides the angular position information. Depending on the

system requirements different magnet diameters are possible. Additional flexibility is given by the wide range of the magnetic

input range. The AS5048 can be combined with NeFeB, SmCo and alternative magnet materials e.g. hard ferrites. The AS5048

provides a 14-bit binary code representing the angular position of the magnet. The type of output is pre-programmed as SPI

version A or I2C version B. Simultaneously a PWM output signal is available in 12 bit format.

A simple programming of the zero position is possible over the interface. No additional programmer is needed. The AS5048

uses one time programmable (OTP) fuses for permanent programming of the user settings. The verification is possible over a

simple digital readout of the OTP content.

4

Operation

4.1

Supply Voltage Configuration

The AS5048 operates at 5V ±10% , using an internal Low-Dropout (LDO) voltage regulator. In addition a 3.3V operation is

possible. The VDD3V output is intended for internal use only. It must not be loaded with an external load.

10 F

100n

F

4.5 - 5.5V

VDD3V

GND

VDD5V

5V Operation

Internal

VDD3.3V

LDO

10

F

3.0 - 3.6V

VDD3V

GND

VDD5V

3.3V Operation

Internal

VDD3.3V

LDO

100n

F

Figure 2: Connec tions for 5V and 3.3V supply voltages

Note

: The pin VDD3V must always be buffered by a 10

F capacitor in 5V operation. It must not be left floating, as this may

cause unstable internal supply voltages which may lead to larger output jitter of the measured angle.

In 3V operation the VDD3V must be shorted to VDD5V. The ambient temperature Tamb is limited to 125 degC in this mode.