as5040 austriamicrosystems, as5040 Datasheet - Page 8

• Manufacturer Part Number: as5040
• Description: 10-bit Programmable Magnetic Rotary Encoder
• Manufacturer: austriamicrosystems

AS5040 10-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER
4
The AS5040 is manufactured in a CMOS standard
process and uses a spinning current Hall technology for
sensing the magnetic field distribution across the surface
of the chip.
The integrated Hall elements are placed around the
center of the device and deliver a voltage representation
of the magnetic field at the surface of the IC.
Through Sigma-Delta Analog / Digital Conversion and
Digital Signal-Processing (DSP) algorithms, the AS5040
provides accurate high-resolution absolute angular
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 20).
Revision 1.8
position information. For this purpose a Coordinate
Functional Description
M a g I N C n
magnet
VDD5V
provides
and
Hall Array
Frontend
Amplifier
LDO 3.3V
M a g D E C n
&
the
angular
that
Cos
VDDV3V
Sin
Figure 4: AS5040 block diagram
indicate
position
Programming
Parameters
Register
DSP
www.austriamicrosystems.com
OTP
The AS5040 senses the orientation of the magnetic field
and calculates a 10-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).
Besides the absolute angular position information the
device
signals. The various incremental output modes can be
selected by programming the OTP mode register bits
(see page 16). As long as no programming voltage is
applied to pin Prog, the new setting may be overwritten
at any time and will be reset to default when power is
turned off. To make the setting permanent, the OTP
register must be programmed (see Figure 15). The
default setting is a quadrature A/B mode including the
Index signal with a pulse width of 1 LSB. The Index
signal is logic high at the user programmable zero
position.
The AS5040 is tolerant to magnet misalignment and
magnetic stray fields due to differential measurement
technique and Hall sensor conditioning circuitry.
Ang
Mag
simultaneously
Incremental
Interface
Absolute
Interface
Interface
PWM
(SSI)
provides
PWM_LSB
DO
CSn
MagINCn
MagDECn
CLK
A_LSB_U
B_Dir_V
Index_W
Prog
incremental
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output