AS5040-ASSU austriamicrosystems, AS5040-ASSU Datasheet - Page 11

• Manufacturer Part Number: AS5040-ASSU
• Description: IC ENCODER PROG 10-BIT 16-SSOP
• Manufacturer: austriamicrosystems
• Type: Linear, Rotary Encoder - Programmabler

Specifications of AS5040-ASSU

• Sensing Range: 45mT ~ 75mT
• Voltage - Supply: 3 V ~ 3.6 V, 4.5 V ~ 5.5 V
• Current - Supply: 21mA
• Current - Output (max): 4mA
• Output Type: Quadrature with Index (Incremental)
• Features: Programmable
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 16-SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AS5040
Data Sheet
Table 3: Magnetic Magnitude Variation Indicator
Note: Pins 1 and 2 (MagINCn, MagDECn) are open drain outputs and require external pull-up resistors. If the
magnetic field is in range, both outputs are turned off.
The two pins may also be combined with a single pull-up resistor. In this case, the signal is high when the magnetic
field is in range. It is low in all other cases (see Table 3).
Even Parity bit for transmission error detection of bits 1…15 (D9…D0, OCF, COF, LIN, MagINCn, MagDECn)
The absolute angular output is always set to a resolution of 10 bit. Placing the magnet above the chip, angular values
increase in clockwise direction by default.
Data D9:D0 is valid, when the status bits have the following configurations:
Table 4: Status Bit Outputs
The absolute angular position is sampled at a rate of 10kHz (0.1ms). This allows reading of all 1024 positions per 360
degrees within 0.1 seconds = 9.76Hz (~10Hz) without skipping any position. Multiplying 10Hz by 60, results the
corresponding maximum rotational speed of 600 rpm.
Readout of every second angular position allows for rotational speeds of up to 1200rpm.
Consequently, increasing the rotational speed reduces the number of absolute angular positions per revolution (see
Table 7). Regardless of the rotational speed or the number of positions to be read out, the absolute angular value is
always given at the highest resolution of 10 bit.
The incremental outputs are not affected by rotational speed restrictions due to the implemented interpolator. The
incremental output signals may be used for high-speed applications with rotational speeds of up to 30,000 rpm without
missing pulses.
Daisy Chain Mode
The Daisy Chain mode allows connection of several AS5040’s in series, while still keeping just one digital input for
data transfer (see “Data IN” in Figure 6 below). This mode is accomplished by connecting the data output (DO; pin 9)
to the data input (Prog; pin 8) of the subsequent device. An RC filter must be implemented between each PROG pin
of device n and DO pin of device n+1, to prevent the encoders to enter the alignment mode, in case of ESD
discharge, long cables, or not conform signal levels or shape. Using the values R=100R and C=1nF allow a max. CLK
frequency of 1MHz on the whole chain. The serial data of all connected devices is read from the DO pin of the first
device in the chain. The Prog pin of the last device in the chain should be connected to VSS. The length of the serial
bit stream increases with every connected device, it is
The last data bit of the first device (Parity) is followed by a logic low bit and the first data bit of the second device (D9),
etc… (see Figure 7).
www.austriamicrosystems.com
OCF
INCn
Mag
1
0
0
1
1
n * (16+1) bits:
e.g. 34 bit for two devices, 51 bit for three devices, etc…
COF
0
DECn
Mag
0
1
0
1
LIN
0
Description
No distance change; Magnetic input field OK (in range, 45..75mT)
Distance increase: Pull-function. This state is dynamic, it is only active while the magnet is
moving away from the chip in Z-axis
Distance decrease: Push- function. This state is dynamic, it is only active while the magnet is
moving towards the chip in Z.-axis.
Magnetic Input Field invalid – out of range: <45mT or >75mT (or missing magnet)
INCn
Mag
0
0
1
DECn
Mag
0
1
0
Revision 2.10
even checksum of bits
Parity
1:15
11 - 33