Rev A3, Page 2/11
The iC-PT H-series represents advanced optical
encoder ICs featuring integrated photosensors ar-
ranged as an HD Phased Array, providing signal ﬁ-
delity at relaxed alignment tolerances.
Its typical application are incremental encoders for
motor speed control and commutation. To this end,
the devices provide differential A/B tracks, a differ-
ential index track and three more tracks to generate
block commutation signals.
Where the optical radius and the native cycles per
revolution (CPR) are determined by the device ver-
sion, the adaption to the motor polecount is carried
out by the code disc, for instance with 4 CPR and
90 degree phase shift to operate 4-phase brushless
Encoder blue® series devices feature blue-enhanced
photosensors requiring the application of a LED with
short wavelenght, preferably iC-TL46. An outstand-
ing jitter performance is the key beneﬁt due to the
improvements in signal contrast.
Low-noise transimpedance ampliﬁers, arranged in a
paired layout to ensure excellent channel matching,
are used to convert the scanner’s signals into volt-
ages of several hundred millivolts2).
Precision comparators with hysteresis generate the
digital signals subsequently, either native or interpo-
lated, which are then output by differential ± 4 mA
The built-in averaging LED power controller with its
40 mA driver permits a direct connection of the en-
coder LED. The received optical power is kept con-
stant regardless of aging effects or changes in tem-
Various operating modes are selectable at multi-level
input SEL3): digital output with native (x1) or inter-
polated resolution (x2 or x4), analog output or mixed
analog/digital output; the latter combines an output
of sine/cosine signals with comparated UVW com-
mutation signals. During analog operation the am-
pliﬁed signal voltages are available at the outputs for
inspection and monitoring of encoder assembly, or to
feed external interplation circuits.
Index gating is also pin-selectable at input T13): the
options are ungated, respectively T-gated if using in-
terpolated output, B-gated and AB-gated.
All devices run at single-sided supplies from 3.5 V up
to 5.5 V and feature a low power consumption.
iC-PT33xxH Encoder blue® Series
Optical radius 14.5 mm, code disc ∅ 33.0 mm;
Native CPR: 2000, 2048, 2500.
1) Standard on code discs available for sampling.
2) Operating point varies by device version and CPR.
3) For ease of replacement, iC-PT H-Series pin functions are backwards
compatible to iC-PT series ICs (except for iC-PT3325 which does not fea-
ture pin T1).
Encoder blue is a trademark of iC-Haus GmbH.