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AS5046

PROGRAMMABLE 12-bit 360° MAGNETIC ANGLE ENCODER WITH ABSOLUTE 2-WIRE SERIAL AND ANALOG INTERFACES

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AS5046 Programmable 360° Magnetic Angle Encoder – Preliminary Data Sheet

An on-chip diagnostic feature turns the analog output off in case of an error (broken supply or magnetic field out of range;

see Table 7).The DAC output can be accessed directly at pin #10 DACout.

The addition of an OPAMP to the DAC output allows a variety of user configurable options, such as variable output voltage

ranges and variable output voltage versus angle response. By adding an external transistor, the analog voltage output can

be buffered to allow output currents up to hundred milliamperes or more.

Furthermore, the OPAMP can be configured as constant current source.

As an OTP option, the DAC can be configured to 2 different output ranges:

a) 0……100% VDACref. The reference point may be either taken from VDD5V/2 or from the external DACref input. The

0…100% range allows easy replacement of potentiometers. Due to the nature of rail-to-rail outputs, the linearity will degrade

at output voltages that are close to the supply rails.

b) 10…..90% VDACref. This range allows better linearity, as the OPAMP is not driven to the rails. Furthermore, this mode

allows failure detection, when the analog output voltage is outside of the normal operating range of 10…90%VDD, as in the

case of broken supply or when the magnetic field is out of range and the analog output is turned off.

11.1 Analog Output Voltage Modes

The Analog output voltage modes are programmable by OTP. Depending on the application, the analog output can be

selected as rail-to-rail output or as clamped output with 10%-90% VDD5V.

The output is ratiometric to the supply voltage (VDD5V), which can range from 3.0V to 5.5V. If the DAC reference is

switched to an external reference (pin DACref), the output is ratiometric to the external reference.

11.1.1 Full Scale Mode

This output mode provides a ratiometric DAC output of (0% to 100%)x Vref *), amplified by the OPAMP stage (default =

internal 2x gain, see Figure 17)

Vref

100%

analog

output

voltage

0V 0°

90°

Note: For simplification, Figure 11

describes a linear output voltage from

rail to rail (0V to VDD). In practice, this

is not feasible due to saturation effects

of the OPAMP output driver transistors.

The actual curve will be rounded

towards the supply rails (as indicated in

Figure 11).

angle

180°

270°

360°

Figure 11: Analog output, full scale mode (shown for 360°mode)

Note: Figure 11 and are shown for 360° operation. See Table 9 (page 24) for further angular range programming options.

11.1.2 Diagnostic Output Mode

Vref

100%

90%

analog

output

voltage

10%

0%

0°

90°

180°

In an error case, the output

voltage is in the grey area

270°

normal

operating

area

angle

360°

Revision 1.1

Figure 12: Diagnostic Output Mode

www.austriamicrosystems.com

In Diagnostic Output Mode (see Figure

12) the analog output of the internal

DAC ranges from 10% - 90% Vref*). In an

error case, either when the supply is

interrupted or when the magnetic field is

in the “red” range, (see Table 7) the

output is switched to 0V and thus

indicates the error condition.

Page 18 of 33

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