AS5030 8-bit Programmable Magnetic Rotary Encoder

Rev. 1.8

www.austriamicrosystems.com

Page 21 of 33

Examples of the overall position error caused by speed, including both propagation delay and filter delay:

Speed (rpm)

Total Position error

100

0.0175°

1000

0.175°

10000

1.75°

8 Reduced Power Modes

The AS5030 can be operated in 3 reduced power modes. All 3 modes have in common that they switch off or freeze parts of the

chip during intervals between measurements. In Low Power Mode or Ultra Low Power Mode, the AS5030 is not operational, but

due to the fast start-up, an angle measurement can be accomplished very quickly and the chip can be switched to reduced

power immediately after a valid measurement has been taken. Depending on the intervals between measurements, very low

average power consumption can be achieved using such a strobed measurement mode.

•

Low Power Mode:

reduced current consumption, very fast start-up. Ideal for short sampling intervals

(<3ms)

•

Ultra Low Power Mode:

further reduced current consumption, but slower start-up than Low Power Mode. Ideal

for sampling intervals from 3….200ms

•

Power Cycle mode:

zero power consumption (externally switched off) during sampling intervals, but

slower start-up than Ultra Low Power Mode. Ideal for sampling intervals 200ms

8.1

Low Power Mode and Ultra Low Power Mode

The AS5030 can be put in Low Power Mode or Ultra

Low Power Mode by simple serial commands, using

the regular connection for 2-wire or 3-wire serial

data transmission (Figure 4 , Figure 8)

The required serial command is SET PWR MODE

Figure 25: Low Power Mode and Ultra Low Power Mode

connection

Note that after returning from Low Power Mode or Ultra Low Power mode to normal operation (PSM = 0), if the Hysteresis is

The two following cases describe the typical loop programmed in the software:

•

Hys = 0 (1 LSB hysteresis):

1.

Wait for CPU interrupt or delay for next angle read (typ. <3ms in LP mode, typ>3ms in ULP mode)

2.

Wake up (PSM = 0)

3.

Set Reset (rst = 1)

4.

Clear Reset (rst = 0)

5.

Wait 0.15ms (Low Power Mode) or 0.5ms (Ultra Low Power Mode)

6.

Check if Lock = 1 then read angle

7.

Enable Low Power Mode or Ultra Low Power Mode (PSM=1)

8.

Return to 1

•

Hys = 1 (No hysteresis)

1.

Wait for CPU interrupt or delay for next angle read (typ. <3ms in LP mode, typ>3ms in ULP mode)

2.

Wake up (PSM = 0)

3.

Wait 0.15ms (Low Power Mode) or 0.5ms (Ultra Low Power Mode)

4.

Check if Lock = 1 then read angle

5.

Enable Low Power Mode or Ultra Low Power Mode (PSM=1)

6.

Return to 1.

ULP/LPn

PSM

Mode

0

0

Normal operation

0

1

Low Power Mode

1

0

Normal operation

1

1

Ultra Low Power Mode

AS5030

Micro

Controller

100n

CS

CLK

DIO

+5V

VDD

VSS

VSS

VSS

VDD

VDD

on/off

S

N

C1 C2

R1: optional;

see text

C1:

optional;

see text