as5040 austriamicrosystems, as5040 Datasheet - Page 14

• Manufacturer Part Number: as5040
• Description: 10-bit Programmable Magnetic Rotary Encoder
• Manufacturer: austriamicrosystems

AS5040 10-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER
10 Programming the AS5040
After power-on, programming the AS5040 is enabled with
the rising edge of CSn with Prog = high and CLK = low.
16 bit configuration data must be serially shifted into the
OTP register via the Prog-pin. The first “CCW” bit is
followed by the zero position data (MSB first) and the
incremental mode setting as shown in Table 6. Data must
be valid at the rising edge of CLK (see Figure 14).
After writing data into the OTP register it can be
permanently programmed by rising the Prog pin to the
programming voltage V
be applied to program the fuses (Figure 15). To exit the
programming mode, the chip must be reset by a power-
on-reset. The programmed data is available after the
next power-up.
Note: During the programming process, the transitions in
the programming current may cause high voltage spikes
generated by the inductance of the connection cable. To
avoid these spikes and possible damage to the IC, the
connection wires, especially the signals Prog and VSS
must be kept as short as possible. The maximum wire
length between the V
Prog (see Figure 16) should not exceed 50mm
(2 inches). To suppress eventual voltage spikes, a 10nF
ceramic capacitor should be connected close to pins
Prog and VSS. This capacitor is only required for
programming, it is not required for normal operation.
The clock timing t
ensure that the signal Prog is stable at the rising edge of
CLK (see Figure 14).
supply voltage should be buffered with a 10µF capacitor
mounted close to the switching transistor. This capacitor
aids in providing peak currents during programming.
Revision 1.8
Position:
CW Direction
Angle:
Commutation - Mode 3.2
U
V
W
0.0
0
clk
Width: 256 Steps
must be selected at a proper rate to
29.88
85
PROG
PROG
Additionally, the programming
Figure 13: U, V and W-signals for 2pole BLDC motor commutation (Div1=1; Div0=0)
. 16 CLK pulses (t
switching transistor and pin
60.12
171
256
90.0
Width: 256 Steps
119.88
341
(Two-pole-pairs)
PROG
) must
150.12
427
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180.0
512
7.5V (see section 3.7). To compensate for the voltage
drop across the V
programming voltage may be set slightly higher (7.5 -
8.0V, see Figure 16).
OTP Register Contents:
CCW
Z [9:0]
Indx
Div1,Div0
Md1, Md0
10.1 OTP Default Setting
The AS5040 can also be operated without programming.
The default, un-programmed setting is shown in Table 6
(Mode 0.0):
CCW: 0
Z9 to Z0: 00
Indx: 0
Div0,Div1 : 00
Md0, MD1: 00
209.88
The specified programming voltage at pin Prog is 7.3 –
ccw=0 – angular value increases in clockwise direction
ccw=1 – angular value increases in counterclockwise
597
240.12
683
Counter Clockwise Bit
Programmable Zero / Index Position
Index Pulse Width Selection: 1LSB / 3LSB
direction
270.00
768
PROG
Divider Setting of Incremental Output
Incremental Output Mode Selection
= clockwise operation
= no programmed zero position
= Index bit width = 1LSB
= incremental resolution = 10bit
= incremental mode = quadrature
299.88
853
switching transistor, the applied
330.12
939
360.0
0
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