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Revision 2.4

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AS5030

Datasheet - Application In formatio n

Figure 24. Magnetic Field Strength Indicator

8.6 High Speed Operation

The AS5030 is using a fast tracking ADC (TADC) to determine the angle of the magnet. The TADC has a tracking rate of 1.15µs (typ).

Once the TADC is synchronized with the angle, it sets the LOCK bit in the status register. In worst case, usually at start-up, the TADC requires a

maximum of 127 steps (127 * 1.15µS = 146.05µs) to lock. Once it is locked, it requires only one cycle (1.15µs) to track the moving magnet.

The AS5030 can operate in locked mode at rotational speeds up to 30.000 rpm.

In Low Power Mode or Ultra-low Power Mode, the position of the TADC is frozen. It will continue from the frozen position once it is powered up

again. If the magnet has moved during the power down phase, several cycles will be required before the TADC is locked again. The tracking time

to lock in with the new magnet angle can be roughly calculated as:

(EQ 3)

Where:

OldPos = Angle position when one of the reduced power modes is activated [°]

NewPos = Angle position after resuming from reduced power mode [°]

8.6.1 Propagation Delay

The Propagation delay is the time required from reading the magnetic field by the Hall sensors to calculating the angle and making it available on

the serial or PWM interface. While the propagation delay is usually negligible on low speeds it is an important parameter at high speeds.

The longer the propagation delay, the larger becomes the angle error for a rotating magnet as the magnet is moving while the angle is calculated.

The position error increases linearly with speed.

The main factors contributing to the propagation delay are:

The fast tracking ADC used in the AS5030 with a tracking rate of only 1.15µs (typ.) is a perfect fit for both high speed and high performance.

100n

CS

CLK

DI O

+5 V

VDD

VSS

VSS

C 2

VDD

VDD

13

11

10

12

15

C1

VSS

3

14

I/O

Output

Output

MagRngn

1

LED 1

1k

Micro

Controller

AS5030

OldPos

NewPos

s

t

LOCK

−

∗

=

μ

15

.

1