iC-LSHB
INCREMENTAL PHOTOSENSOR ARRAY
nar y
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Rev B1, Page 2/8
DESCRIPTION
iC-LSHB is an optical sensor IC with 6 integrated
photodiodes whose signal currents are converted
into output voltages by low-noise transimpedance
amplifiers.
The IC is well suited for the operation of interpolation
circuits for linear or rotary incremental encoders with
an index signal. iC-LSHB thus has a shamrock-style
sensor layout of four photodiodes, each with an ac-
tive area of 800 µm x 330 µm. Both a positive and
negative sine signal and a positive and negative co-
sine signal are generated from a single shared code
track. The signal amplifier layout ensures excellent
paired channel matching, reducing signal differences
to an absolute minimum.
Two separate photodiodes, with active areas of 1720
µm x 150 µm apiece, are employed for the differential
scanning of the index track and to generate the zero
signal.
The spectral sensitivity ranges from visible to near
infrared light, with the maximum sensitivity close to a
wavelength of 680 nm.
Due to a high transimpedance gain of typically 4 MΩ,
signal voltages of several hundred millivolts are ob-
tained at low illumination levels. An output signal
amplitude of 1 V is typical in low light conditions,
for instance when iC-LSHB is illuminated at only
0.2 mW/cm
2
by a 740 nm LED.
A threefold intensity is sufficient when using iC-LSHB
for encoder applications with typical disc and mask
codes. Therefore, a relatively low LED current is
enough to operate the sensor, proving beneficial to
the life expectancy of the LED at high operating tem-
peratures.
iC-LSHB is suitable for on-chip or LED-end mounting
of the grating (reticle), so that the period count, signal
waveform, phase shift and index marker code can be
selected with flexibility.
PACKAGES
PAD LAYOUT (2.88 mm x 2.04 mm)
PAD FUNCTIONS
No. Name Function
1
2
3
4
5
6
7
8
VCC
PZ
NZ
GND
NCOS
PCOS
NSIN
PSIN
+4.5..5.5 V Supply Voltage
Zero Signal (Index)
Reference Voltage Output
Ground
Cosine -
Cosine +
Sine -
Sine +
Notes: All outputs supply analog volt-
ages.
Dimension G4 is the reference radius of
the chip center.
ICHAUS [ IC-HAUS GMBH ]
