IC-LV_16 Datasheet, PDF (2/15 Pages) IC-Haus GmbH – 5-BIT OPTO ENCODER

iC-LV
5-BIT OPTO ENCODER
Rev C1, Page 2/15
DESCRIPTION
iC-LV is an optoelectronic encoder IC for absolute
linear and angle measuring systems such as glass
scales and shaft encoders, for example. Photosen-
sors, amplifiers and comparators for 5 tracks at a pitch
of 600 µm and a reference photosensor operating the
LED power control are monolithically integrated on
the chip.
The internal comparator outputs switch to high when
the amplified photocurrents exceed a given threshold
(constant light evaluation). This threshold can be ad-
justed using an external resistor at RSET; alternatively,
if RSET is not wired an internal resistor is used.
The internal or external resistor also establishes a
setpoint for the LED current control which irrespec-
tive of temperature or the effects of aging keeps the
optical receive power constant. A driver stage en-
ables either a transmitting LED with a series resistor
to be directly connected to the device or operates an
external transistor to generate higher currents.
Track information can be read out in parallel (either
in Gray or binary code) or serially via an SSI protocol.
Here, any number of iC-LVs can be cascaded and
synchronized with one another; data is then output as
a binary word (requiring Gray code discs).
A watchdog generates an alarm message via the error
output if the LED current control range is exceeded.
The open-drain error output can be wired to a bus;
the signal is then low active. The serial data output
can also be complemented by the error bit.
All inputs and outputs are protected against destruc-
tion by ESD. Two different test modes can be selected
by pin and permit a complete test of functions with the
exception of the photosensors.
PACKAGING INFORMATION
PAD LAYOUT
RC
VCCA
VDD
LVCC
NINV
MODE
TEST
RSET
NERR
NDIR
D0
D1
D2
D3
D4
DREF
1) Wiring is optional.
2) Pad must be connected to VDD.
3) Pad must be connected to GND.
SEEN
SYNM1
SYNM0
SCLK
SERIN
SOUT
GND
AGND
LED
PAD FUNCTIONS
No. Name Function
RC¹⁾ RC Network for SSI Monoflop
VCCA²⁾ +4...+5.5 V Analog Supply Voltage
VDD +4...+5.5 V Digital Supply Voltage
LVCC +4...+5.5 V LED Driver Supply Voltage
NINV Bit-wise Inversion Input (low active)
MODE Operating Mode Selection Input
TEST Test Mode Enable Input (high active)
RSET¹⁾ LED Power Control Adjustment
NERR Error Output (low active)
NDIR Direction Input (low active)
LED LED Power Control Output
(high-side current source)
AGND³⁾ Analog Ground
GND Digital Ground
SOUT Serial Data Output (SSI)
/ Data Output D4
SERIN Serial Data Input (SSI) / Data Outp. D3
SCLK Clock Input (SSI) / Data Output D2
SYNM0 Synchronisation Mode Input
/ Data Output D1
SYNM1 Synchronisation Mode Input
/ Data Output D0
SEEN Serial Error Bit Enable Inp. (high act.)