iC-PT 3325
6-CH. PHASED ARRAY OPTO ENCODER (33-2500)
Rev A4, Page 2/10
DESCRIPTION
iC-PT 3325 is an optical sensor IC with integrated available at the outputs for inspection and monitoring
photosensors whose signals are converted into volt- encoder assembly.
ages by low-noise transimpedance amplifiers. Pre-
cise voltage comparators with hysteresis are used to Typical applications of iC-PT devices are incremental
generate the digital signals, supplied to the output encoders for motor feedback and commutation. To
pins via differential +/- 4 mA push-pull drivers.
this end, device version iC-PT 3325 provides differ-
ential A/B tracks and a differential index track, each
The built-in LED power control with its 40 mA driver consisting of multiple photo sensors. The layout of
stage permits a direct connection of the encoder the signal amplifiers is such that there is an excellent
LED. Regardless of aging or changes in temperature paired channel matching, eliminating the needs for
the received optical power is kept constant. An exter- signal calibration in most cases.
nal resistor presets the photocurrent operating point
and thus the desired illumination level.
Additionally, three more tracks are provided to gener-
ate motor commutation information for the U, V and
Selection input SEL chooses for three different op- W outputs, for instance with 90 degree phase shift to
erating modes: regular A/B operation, A/B operation operate 4-phase brushless motors (period count and
with 2-fold interpolation, or analog operation. With phase shift can be varied by the code disc applied).
analog operation the amplified signal voltages are
ICHAUS [ IC-HAUS GMBH ]
