AS5130ATST AMSCO [austriamicrosystems AG], AS5130ATST Datasheet - Page 24

• Manufacturer Part Number: AS5130ATST
• Description: 8 Bit Programmable Magnetic Rotary Encoder with Motion Detection & Multiturn
• Manufacturer: AMSCO [austriamicrosystems AG]

AS5130
Data Sheet - D e t a i l e d D e s c r i p t i o n
If the AS5130 is cycled between active and reduced current mode, a substantial reduction of the average supply
current can be achieved. The minimum dwelling time in active mode is the wake-up time. The actual active time
depends on how much the magnet has moved while the AS5130 was in reduced power mode. The angle data is valid,
when the status bit LOCK has been set
back to reduced power mode. The average power consumption can be calculated as:
Where:
I
I
I
t
t
Reducing Power Supply Peak Currents
An optional RC-filter (Rx/Cx) may be added to avoid peak currents in the power supply line when the AS5130 is
toggled between active and reduced power mode. Rx must be chosen such that it can maintain a V
5.5V under all conditions, especially during long active periods when the charge on Cx has expired. Cx should be
chosen such that it can support peak currents during the active operation period. For long active periods, Cx should be
large and Rx should be small.
Power Cycling Mode
The power cycling method shown in
transistor high side switch. The current consumption in off-mode is zero. It also has the longest start-up time of all
modes, as the chip must always perform a “cold start “ from zero, which takes about 1.9 ms (Compare with
Mode on page
Figure 17. Power Cycling Mode
The optional filter Rx/Cx may again be added to reduce peak currents in the 5V power supply line
Power Supply Peak Currents on page
Polling Mode
Target of this mode is a reduction of the average power consumption. In this mode, the IC supply is pulsed, thereby
reducing the average power consumption to a fraction. The actual angle information and multi turn count value is not
lost; polling mode is especially suited for battery powered applications. The IC is furthermore capable of generating a
WAKE signal as soon as the magnet’s position has changed, but only if the supply of the IC is powered-on again. By
means of the WAKE signal, the system’s power consumption can be further decreased, if certain modules are
activated on demand.
www.austriamicrosystems.com
avg
active
power_down
on
off
= Time period during which the chip is operated in active mode
= Ttime period during which the chip is in reduced power mode
= Average current consumption
= Current consumption in active mode
= Current consumption in reduced power mode
23).
I
avg
=
100n
I
-------------------------------------------------------------------- -
active
∗ t
Figure 17
AS5130
AS5130
on
24).
(see Table
t
on
S
+
V
V
SS
I
+
DD
powerdown
t
I
off
on
0
N
C1
cycles the AS5130 by switching it on and off, using an external PNP
t
on
9). Once a valid angle has been measured, the AS5130 can be put
t
off
∗ t
Revision 1.00
off
10k
CS
DCLK
DIO
Rx
sampling interval = t
>µF
Cx
t
on
t
off
on/off
controller
micro
V
on
V
DD
SS
+ t
off
V
+5V
V
DD
SS
(see Reducing
DD
voltage of 4.5 –
Low Power
24 - 41
(EQ 7)