IC-PVL Datasheet, PDF (14/33 Pages) IC-Haus GmbH – LINEAR/OFF-AXIS BATTERY-BUFFERED HALL MULTITURN ENCODER

iC-PVL LINEAR/OFF-AXIS
preliminary
BATTERY-BUFFERED HALL MULTITURN ENCODER
STARTUP BEHAVIOR
Rev B3, Page 14/33
As shown in the previous chapter, iC-PVL can be
booted up in four distinct operating modes. These are
the SSI Mode, the Chain Mode, the Parallel Encoder
Mode and the I²C Slave Mode, respectively. In case of
a faulty startup procedure, an error is indicated at pin
NERR.
Figure 7 shows the startup procedure of iC-PVL. The
procedure starts when a battery supply is available.
This would be the case if a battery is newly attached to
the encoder system or the battery supply is switched
on by an external microcontroller.
install battery
apply VDD
apply preset pulse to input PRE
1
SEL = ?
PRE
0
no
VDD ok ?
yes
(external supply)
I2C interface active
=> read EEPROM
(max. 3 times on error)
EEPROM ok ?
no
yes
counter preload
INT_MODE ?
0
1
Parallel Encoder
Mode
I2C Slave Mode
no EEPROM read
Error
Output
SSI Mode
Chain Mode
Figure 7: Startup behavior
Subsequent to powering up the VBAT pin, a suitable
magnetic target needs to be installed, the main supply
VDD powered, and a preset pulse (low-high-low) ap-
plied to input PRE. This resets the internal circuitry to
its default initial state.
Via SEL, the operating mode is selected according to
Table 8. If SEL = high, the chip functions as a 3 bit en-
coder with parallel complementary output and encodes
the current position as shown in Figure 11.
In Parallel Encoder Mode, an external microcontroller
activates the iC-PVL in distinct intervals to acquire the
current position. The encoded position is valid when all
complementary bits have changed their logic value (see
Figure 11). After successful position read-out, iC-PVL
is in ultra low power idle mode. The battery supply may
then be switched off.
If SEL = low and for V(VDD) > V_on during startup, the
preset pulse triggers EEPROM read-out. Therefore, the
VDD supply has to remain above V_on for at least t_config.