AS5140H-ASSU austriamicrosystems, AS5140H-ASSU Datasheet - Page 17

• Manufacturer Part Number: AS5140H-ASSU
• Description: ENCODER, MAGNETIC, ROTARY, 10BIT, 16SSOP
• Manufacturer: austriamicrosystems

Specifications of AS5140H-ASSU

• Brief Features: User Programmable Zero / Index Position, Failure Detection Mode
• Supply Voltage Range: 3V To 3.6V, 4.5V To 5.5V
• Operating Temperature Range: -40°C To +150°C
• Digital Ic Case: RoHS Compliant
• Ic Function: 10-bit Programmable Magnetic Rotary Encoder
• Rohs Compliant: Yes

AS5140H
Data Sheet - D e t a i l e d D e s c r i p t i o n
Incremental Output Hysteresis
To avoid flickering incremental outputs at a stationary magnet position, a hysteresis is introduced. In case of a
rotational direction change, the incremental outputs have a hysteresis of 2 LSB. Regardless of the programmed
incremental resolution, the hysteresis of 2 LSB always corresponds to the highest resolution of 10 bit. In absolute
terms, the hysteresis is set to 0.704 degrees for all resolutions. For constant rotational directions, every magnet
position change is indicated at the incremental outputs
position „x+3“ to „x+4“, the incremental output would also indicate this position accordingly. A change of the magnet’s
rotational direction back to position “x+3“ means that the incremental output still remains unchanged for the duration of
2 LSB, until position “x+2“ is reached. Following this direction, the incremental outputs will again be updated with every
change of the magnet position.
Figure 9. Hysteresis Window for Incremental Outputs
Pulse Width Modulation (PWM) Output
The AS5140H provides a pulse width modulated output (PWM), whose duty cycle is proportional to the measured
angle:
The PWM frequency is internally trimmed to an accuracy of ±5% (±10% over full temperature range). This tolerance
can be cancelled by measuring the complete duty cycle as shown above.
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the waiting time at power-up. Instead of waiting for the specified maximum power up-time (0), the controller can
start requesting data from the AS5140H as soon as the state (A=B=Index = high) is cleared.
CSn = high or open at power-up: In this mode, the incremental outputs (A, B, Index) will remain at logic high state,
until CSn goes low or a low pulse is applied at CSn. This mode allows intentional disabling of the incremental out-
puts until, for example the system microcontroller is ready to receive data.
Incremental
Indication
Output
X+1
X+4
X+3
X+2
X
X
X+1
Position =
Counterclockwise Direction
Clockwise Direction
X+2
Hysteresis:
0.7º
X+3
Revision 1.1
------------------------ - 1
(
(see Figure
t
t
on
on
⋅
+
X+4
1025
t
off
)
X+5
–
9). For example, if the magnet turns clockwise from
Magnet Position
17 - 38
(EQ 2)