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AS5134

Data Sheet - D e ta i l e d D e s c r i p t i o n

Figure 15. Low/Mid Power Mode Connection

In Low/Mid Power Mode, the AS5134 is inactive. The last state, e.g. the angle, AGC value, etc. is frozen and the chip

starts from this frozen state when it resumes active operation. This method provides much faster start-up than a “cold

start” from zero. If the AS5134 is cycled between active and reduced current mode, a substantial reduction of the

average supply current can be achieved. The minimum dwelling time is <0.5 ms. The actual active time depends on

how much the magnet has moved while the AS5134 was in reduced power mode. The angle data is valid, when the

status bit LOCK has been set. Once a valid angle has been measured, the AS5134 can be put back to reduced power

mode. The average power consumption can be calculated as:

(EQ 5)

Where:

Reducing Power Supply Peak Currents

An optional RC-filter (R1/C1) may be added to avoid peak currents in the power supply line when the AS5134 is

toggled between active and reduced power mode. R1 must be chosen such that it can maintain a VDD voltage of 4.5 –

5.5V under all conditions, especially during long active periods when the charge on C1 has expired. C1 should be

chosen such that it can support peak currents during the active operation period. For long active periods, C1 should be

large and R1 should be small.

Power Cycling Mode

The power cycling method shown in Figure 16 cycles the AS5134 by switching it on and off, using an external PNP

transistor high side switch. This mode provides the least power consumption of all three modes; when the sampling

interval is more than 400ms, as 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 1.3 ms. The optional filter R1/C1

may again be added to reduce peak currents in the 5V power supply line.

R1

AS5134

VDD

C1

C2

100n

VSS

+5V

VDD

Micro

Controller

CS

DCLK

DIO

VSS

VSS

VDD

on/off

S

N

+

+

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