AS5245-HQFT-500 austriamicrosystems, AS5245-HQFT-500 Datasheet - Page 10

• Manufacturer Part Number: AS5245-HQFT-500
• Description: IC ENCODER ROTARY 32-QFN
• Manufacturer: austriamicrosystems
• Type: Linear, Rotary Encoder - Programmabler

Specifications of AS5245-HQFT-500

• Featured Product: AS5245 – Dual Die Motion Sensing IC
• Sensing Range: 45mT ~ 75mT
• Voltage - Supply: 3 V ~ 3.6 V, 4.5 V ~ 5.5 V
• Current - Supply: 21mA
• Current - Output (max): 4mA
• Output Type: Quadrature with Index (Incremental)
• Features: Programmable
• Operating Temperature: -40°C ~ 150°C
• Package / Case: 32-VQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: AS5245-HQFT-500TR

AS5245
Data Sheet - D e t a i l e d D e s c r i p t i o n
8 Detailed Description
The AS5245 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 AS5245 provides accurate high-resolution
absolute angular position information. For this purpose, 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 MagINCn and MagDECn that indicate
movements of the used magnet towards or away from the device’s surface. A small low cost diametrically magnetized (two-pole) standard
magnet provides the angular position information
The AS5245 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 analog voltage, by using an external Low-Pass-Filter. The AS5245 is tolerant to
magnet misalignment and magnetic stray fields due to differential measurement technique and Hall sensor conditioning circuitry.
Figure 4. Typical Arrangement of AS5245 and Magnet
8.1 Mode_Index Pin
The Mode_Index 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 0.03º 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 0.06º rms. This mode is
recommended for higher speed applications.
Setting up the Mode pin affects the following parameters:
Table 6. Slow and Fast Mode Parameters
Note: A change of the Mode during operation is not allowed. The setup must be constant during power up and during operation.
www.austriamicrosystems.com/AS5245
Maximum speed @ 4096 samples/rev
Maximum speed @ 1024 samples/rev
Maximum speed @ 256 samples/rev
Maximum speed @ 64 samples/rev
Transition noise (1 sigma)
Sampling rate
Output delay
Parameter
(see Figure
Slow Mode (mode=low or open)
16).
2.61 kHz (384 µs)
≤ 0.03º rms
2441 rpm
153 rpm
610 rpm
38 rpm
Revision 1.5
384µs
Fast Mode (mode=high, V
10.42 kHz (96µs)
≤ 0.06º rms
2441 rpm
9766 rpm
153 rpm
610 rpm
96µs
DD
=5V)
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