as5030 austriamicrosystems, as5030 Datasheet - Page 21

• Manufacturer Part Number: as5030
• Description: 8-bit High-speed Absolute Magnetic Rotary Encoder
• Manufacturer: austriamicrosystems

AS5030 8-bit Programmable Magnetic Rotary Encoder
Examples of the overall position error caused by speed, including both propagation delay and filter delay:
8
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.
8.1
Note that after returning from Low Power Mode or Ultra Low Power mode to normal operation (PSM = 0), if the Hysteresis is
enabled (Hys=0), a general reset must be performed: set bit RST and then clear bit RST using command 15
The two following cases describe the typical loop programmed in the software:
Rev. 1.8
optional;
see text
C1:
•
•
•
•
•
Reduced Power Modes
Low Power Mode and Ultra Low Power Mode
Low Power Mode:
Ultra Low Power Mode:
Power Cycle mode:
Hys = 0 (1 LSB hysteresis):
1.
2.
3.
4.
5.
6.
7.
8.
Hys = 1 (No hysteresis)
1.
2.
3.
4.
5.
6.
connection
100n
Wait for CPU interrupt or delay for next angle read (typ. <3ms in LP mode, typ>3ms in ULP mode)
Wake up (PSM = 0)
Set Reset (rst = 1)
Clear Reset (rst = 0)
Wait 0.15ms (Low Power Mode) or 0.5ms (Ultra Low Power Mode)
Check if Lock = 1 then read angle
Enable Low Power Mode or Ultra Low Power Mode (PSM=1)
Return to 1
Wait for CPU interrupt or delay for next angle read (typ. <3ms in LP mode, typ>3ms in ULP mode)
Wake up (PSM = 0)
Wait 0.15ms (Low Power Mode) or 0.5ms (Ultra Low Power Mode)
Check if Lock = 1 then read angle
Enable Low Power Mode or Ultra Low Power Mode (PSM=1)
Return to 1.
AS5030
S
VDD
VSS
N
C1 C2
(<3ms)
slower start-up than Ultra Low Power Mode. Ideal for sampling intervals 200ms
CS
CLK
DIO
reduced current consumption, very fast start-up. Ideal for short sampling intervals
further reduced current consumption, but slower start-up than Low Power Mode. Ideal
for sampling intervals from 3….200ms
zero power consumption (externally switched off) during sampling intervals, but
I
I
on
off
Speed (rpm)
100
1000
10000
t
on
R1: optional;
see text
t
off
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on/off
Controller
Micro
(Δφ
0.0175°
0.175°
1.75°
VSS
VDD
Total Position error
pd +
VDD
Δφ
+5V
VSS
lpf
)
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
(11
Figure 25: Low Power Mode and Ultra Low Power Mode
H
, see 5.2.3):
ULP/LPn
0
0
1
1
PSM
0
1
0
1
Mode
Normal operation
Low Power Mode
Normal operation
Ultra Low Power Mode
H
(see 5.2.2).
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