AS5045ASSU austriamicrosystems, AS5045ASSU Datasheet - Page 16

• Manufacturer Part Number: AS5045ASSU
• Description: IC, MAGNETIC ROTARY ENCODER 12BIT SSOP16
• Manufacturer: austriamicrosystems

Specifications of AS5045ASSU

• Ic Function: Encoder IC
• Supply Voltage Range: 3V To 3.6V, 4.5V To 5.5V
• Operating Temperature Range: -40°C To +125°C
• Digital Ic Case Style: SSOP
• No. Of Pins: 16
• Msl: MSL 3 - 168 Hours
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER
8.4
Non-volatile programming (OTP) uses on-chip zener
diodes, which become permanently low resistive when
subjected to a specified reverse current.
The quality of the programming process depends on the
amount of current that is applied during the programming
process (up to 130mA). This current must be provided by
an external voltage source. If this voltage source cannot
provide adequate power, the zener diodes may not be
programmed properly.
In order to verify the quality of the programmed bit, an
analog level can be read for each zener diode, giving an
indication whether this particular bit was properly
programmed or not.
To put the AS5045 in Analog Readback Mode, a digital
sequence must be applied to pins CSn, PROG and CLK
as shown in Figure 13. The digital level for this pin
depends on the supply configuration (3.3V or 5V; see
section 0).
The second rising edge on CSn (OutpEN) changes pin
PROG to a digital output and the log. high signal at pin
PROG must be removed to avoid collision of outputs
(grey area in Figure 13).
Revision 1.5
PROG
CSn
CLK
Analog Readback Mode
ProgEN
t
LoadProg
OutpEN
Internal
test bit
digital
Prog changes to Output
V
ref
halfEN
PWM
1
Figure 13: OTP register analog read
www.austriamicrosystems.com
Comp
Mag
EN
PWM
Dis
CLK
Z0
Analog Readback Data at PROG
Aread
V
V
programmed
unprogrammed
The following falling slope of CSn changes pin PROG to
an analog output, providing a reference voltage V
must be saved as a reference for the calculation of the
subsequent programmed and unprogrammed OTP bits.
Following this step, each rising slope of CLK outputs one
bit of data in the reverse order as during programming
(see Figure 10: Md0-MD1-Div0,Div1-Indx-Z0…Z11, ccw).
If a capacitor is connected to pin PROG, it should be
removed during analog readback mode to allow a fast
readout rate. If the capacitor is not removed the analog
voltage will take longer to stabilize due to the additional
capacitance.
The measured analog voltage for each bit must be
subtracted from the previously measured V
resulting value gives an indication on the quality of the
programmed bit: a reading of <100mV indicates a
properly programmed bit and a reading of >1V indicates
a properly unprogrammed bit.
A reading between 100mV and 1V indicates a faulty bit,
which may result in an undefined digital value, when the
OTP is read at power-up.
Following the 18
must be reset by disconnecting the power supply.
Z7
Z8
th
clock (after reading bit “ccw”), the chip
Z9
Z10
Z11
CCW
16
Power-on-
Reset;
turn off
supply
ref
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