Data Sheet

ADA4570

TERMINOLOGY

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Rev. 0 | 9 of 14

Output Signals

The output signals, VSIN+, VSIN−, VCOS+, and VCOS−, of the

ADA4570 are biased around a common-mode voltage of VDD/2 as

shown in Figure 14.

Figure 14. Single-Ended Output Voltage Range

The differential signal outputs, VSIN and VCOS, shown in Figure 15

are generated by sampling the corresponding positive and negative

SIN and COS single-ended outputs.

Figure 15. Differential Output Voltage Range

Reference Position Error

The reference position error is the deviation of the sensing element

center from the nominal position shown in Figure 22.

Reference Angle Error

The reference angle error, indicated in Figure 16, is the absolute

mounting angle error of the sensor from its nominal placement. The

angle Φ = 0° is referred to the straight line between the top of Pin 2

and Pin 7.

Figure 16. Sensor Alignment in Package

Uncorrected Angular Error

The uncorrected angular error is defined as the maximum deviation

from an ideal angle without any calibration applied to the VSIN and

VCOS differential signals.

Single Point Calibration Angular Error

The single point calibration angular error is defined as the deviation

from an ideal angle after the offset calibration is applied to the VSIN

and VCOS differential signals at 25°C.

Dynamic Angular Error

The dynamic angular error is defined as the maximum deviation

from an ideal angle with the continuous offset and gain calibration

applied to the VSIN and VCOS differential signals.

Output Amplitude Synchronism

The output amplitude synchronism (k) is defined as the ratio be-

tween the differential amplitudes of both channels when under

a continuously rotating magnetic field. To calculate the amplitude

synchronism, use the following equations:

Propagation Delay

The propagation delay is the amount of time taken for the signal

to propagate to the VSIN and VCOS differential signal outputs in

response to a magnetic stimulus change.

Phase Error

The phase error is defined as the average of the phase shift in

the sine and cosine signal through the amplifier. The phase error in-

creases with the rotation frequency due to the bandwidth limitation

of the instrumentation amplifiers. As shown in Figure 12, the typical

characteristics value can be used as a first-order compensation for

the phase error.

Orthogonality Error

The orthogonality error is the internal phase error caused by mis-

alignment of the sine and cosine sensor elements on-chip, with

respect to the ideal 90° sine to cosine phase.

Single-Ended Output Voltage Low

The single-ended output voltage low is the maximum voltage level

at the VSIN+, VSIN−, VCOS+, and VCOS− outputs when a broken

bond wire is detected and all outputs are pulled low, see Figure 14.