HCTL-1101 Datasheet, PDF (13/40 Pages) AVAGO TECHNOLOGIES LIMITED – General Purpose Control ICs Position and Velocity Control Low Power CMOS

Encoder Input Pins (CHA, CHB, INDEX)
The HCTL-1101 accepts TTL compatible outputs from 2
and 3 channel incremental encoders such as the HEDS-
5XXX, 6XXX, and 9XXX series encoders. Channels A and
B are internally decoded into quadrature counts which
increment or decrement the 24-bit position counter.
For example, a 500-count encoder is decoded into 2000
quadrature counts per revolution. The position counter
will be incremented when Channel B leads Channel A. The
INDEX channel is used only for the Commutator and its
function is to serve as a reference point for the internal
Ring Counter.
The HCTL-1101 employs an internal 3-bit state delay filter
to remove any noise spikes from the encoder inputs to the
HCTL-1101. This 3-bit state delay filter requires the encod-
er inputs to remain stable for three consecutive clock ris-
ing edges for an encoder pulse to be considered valid by
the HCTL-1101’s actual position counter (i.e., an encoder
pulse must remain at a logic level high or low for three
consecutive clock rising edges for the HCTL-1101’s actual
position counter to be incremented or decremented.) The
designer should therefore generally avoid creating the en-
coder pulses of less than 3 clock cycles.
The INDEX signal of an encoder is used in conjunction
with the Commutator. It resets the internal ring counter
which keeps track of the rotor position so that no cumula-
tive errors are generated. The INDEX pin of the HCTL-1101
also has a 3-bit filter on its input. The INDEX pin is active
low and level transition sensitive. It detects a valid high-
to-low transition and qualifies the low input level through
the 3-bit filter. At this point, the INDEX signal is internally
detected by the commutator logic. This type of configu-
ration allows an INDEX signal to be used to generate the
reference mark for commutator operation as long as the
AC specifications for the INDEX signal are met.
Motor Command Port (MC0MC7)
The 8-bit Motor Command port consists of register R08H
whose data goes directly to external pins MC0-MC7. MC7
is the most significant bit. R08H can be read and written
to; however, it should be written to only during the Initial-
ization/Idle mode. During any of the four Control modes,
the controller writes the motor command into R08H.
This topic is further discussed in the “Register Section” un-
der “Motor Command Register R08H”.
Pulse Width Modulation (PWM) Output Port (Pulse, Sign).
The PWM port consists of the Pulse and Sign pins. The
PWM port outputs the motor command as a pulse width
modulated signal with the correct polarity. This topic is
further discussed in the “Register Section” under “PWM
Motor Command Register R09H”.
Trapezoid Profile Pin (Prof)
The Trapezoid Profile Pin is internally connected to soft-
ware flag bit 4 in the Status Register. This flag is also rep-
resented by bit 0 in the Flag Register (R00H). See the “Reg-
ister Section” for more information. Both the Pin and the
Flag indicate the status of a trapezoid profile move. When
the HCTL-1101 begins a trapezoid move, this flag is set by
the controller (a high level appears on the pin), indicating
the move is in progress. When the HCTL-1101 finishes the
move, this flag is cleared by the controller.
Note that the instant the flag is cleared may not be the
same instant the motor stops. The flag indicates the com-
pletion of the command profile, not the actual profile. If
the motor is stalled during the move, or cannot physically
keep up with the move, the flag will be cleared before the
move is finished.
INIT/IDLE Pin (INIT)
This pin indicates that the HCTL-1101 is in the INIT/IDLE
mode, waiting to begin control. This pin is internally
connected to the software flag bit 5 in the Status
Register R07H. This flag is also represented by bit 1 in the
Flag Register (R00H) (See the “Register Section” for more
information).
Commutator Pins (PHA-PHD)
These pins are connected only when using the commuta-
tor of the HCTL-1101 to drive a brushless motor or step
motor. The four pins can be programmed to energize each
winding on a multiphase motor.
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