as5045 austriamicrosystems, as5045 Datasheet - Page 4

• Manufacturer Part Number: as5045
• Description: 12-bit Programmable Magnetic Rotary Encoder
• Manufacturer: austriamicrosystems

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER
4.1
If CSn changes to logic low, Data Out (DO) will change from
high impedance (tri-state) to logic high and the read-out will
be initiated.
Placing the magnet above the chip, angular values increase in clockwise direction by default.
Data D11:D0 is valid, when the status bits have the following configurations:
*) MagInc=MagDec=1 is only recommended in YELLOW mode (see Table 5)
Revision 1.2, 03-Oct-06
CSn
CLK
DO
After a minimum time t
output shift register with the first falling edge of CLK.
Each subsequent rising CLK edge shifts out one bit of
data.
The serial word contains 18 bits, the first 12 bits are
the angular information D[11:0], the subsequent 6 bits
contain system information, about the validity of data
such as OCF, COF, LIN, Parity and Magnetic Field
status (increase/decrease) .
A subsequent measurement is initiated by a “high”
pulse at CSn with a minimum duration of t
t
DO active
Synchronous Serial Interface (SSI)
t
CLK FE
1
D11
T
t
CLK/2
DO valid
D10
CLK FE,
D9
Figure 4: Synchronous serial interface with absolute angular position data
OCF
D8
data is latched into the
1
D7
Angular Position Data
COF
0
D6
CSn.
www.austriamicrosystems.com
D5
LIN
12-bit Absolute Angular Position Output
Table 3: Status bit outputs
0
8
D4
Mag
INC
D3
1*)
0
0
1
D2
4.1.1
Mag
DEC
D11:D0 absolute angular position data (MSB is clocked
out first)
OCF
indicates the finished Offset Compensation Algorithm
COF (Cordic Overflow), logic high indicates an out of
range error in the CORDIC part. When this bit is set, the
data at D9:D0 is invalid. The absolute output maintains
the last valid angular value.
This alarm may be resolved by bringing the magnet
within the X-Y-Z tolerance limits.
LIN (Linearity Alarm), logic high indicates that the input
field
When this bit is set, the data at D9:D0 may still be used,
but can contain invalid data. This warning may be
resolved by bringing the magnet within the X-Y-Z
tolerance limits.
Even Parity bit for transmission error detection of bits
1…17 (D11…D0, OCF, COF, LIN, MagINC, MagDEC)
D1
1*)
0
1
0
D0
Data Content
(Offset
Parity
generates
OCF COF
checksum of
bits 1:15
even
Compensation
Status Bits
LIN
a
Mag
INC
critical
DEC
Mag
18
Finished),
Even
PAR
t
DO Tristate
t
output
CSn
t
CLK FE
logic
Page 4 of 23
linearity.
1
high
D11