as5045 austriamicrosystems, as5045 Datasheet - Page 3

• Manufacturer Part Number: as5045
• Description: 12-bit Programmable Magnetic Rotary Encoder
• Manufacturer: austriamicrosystems

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER
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
movements of the used magnet towards or away from the
device’s surface.
A small low cost diametrically magnetized (two-pole)
standard
information (see Figure 16).
4
The mode input pin activates or deactivates an internal filter, that is used to reduce the analog output noise.
Activating the filter (Mode pin = LOW or open) provides a reduced output noise of 0.03° rms. At the same time, the output
delay is increased to 384µs. This mode is recommended for high precision, low speed applications.
Deactivating the filter (Mode pin = HIGH) reduces the output delay to 96µs and provides an output noise of 0.06° rms. This
mode is recommended for higher speed applications.
Switching the Mode pin affects the following parameters:
Revision 1.2, 03-Oct-06
Parameter
sampling rate
transition noise (1 sigma)
output delay
max. speed @ 4096 samples/rev.
max. speed @ 1024 samples/rev.
max. speed @ 256 samples/rev.
max. speed @ 64 samples/rev.
Mode Input Pin
M a g I N C n
magnet
provides
and
M a g D E C n
the
angular
slow mode (Mode = low or open)
2.61 kHz (384 µs)
≤ 0.03° rms
384µs
38 rpm
153 rpm
610 rpm
2441 rpm
that
Table 2: Slow and fast mode parameters
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Figure 3: AS5045 block diagram
indicate
position
The AS5045 senses the orientation of the magnetic field
and calculates a 12-bit binary code. This code can be
accessed via a Synchronous Serial Interface (SSI). In
addition, an absolute angular representation is given by a
Pulse Width Modulated signal at pin 12 (PWM). This
PWM signal output also allows the generation of a direct
proportional analogue voltage, by using an external Low-
Pass-Filter.
The AS5045 is tolerant to magnet misalignment and
magnetic stray fields due to differential measurement
technique
and
fast mode (Mode = high, VDD5V)
10.42 kHz (96µs)
≤ 0.06° rms
96µs
153 rpm
610 rpm
2441 rpm
9766 rpm
Hall
sensor
conditioning
Page 3 of 23
circuitry.