Quadrature Encoder/Hall-Effect Interface; Zero-Crossing Detection; Zero-Crossing Encoder Interface - Motorola 56F805 Hardware User Manual

2.18 Quadrature Encoder/Hall-Effect Interface

The 56F805EVM board contains a Primary and Secondary Quadrature
Encoder/Hall-Effect interface connected to the hybrid controller's first and second Quad
Encoder input ports. The circuit is designed to accept +3.0V to +5.0V encoder or
Hall-Effect sensor inputs. Input noise filtering is supplied on the input path for the
Quadrature Encoder/Hall-Effect interface, along with additional noise rejection circuitry
inside the device. Figure 2-16
encoder interface is a duplicate of the primary encoder interface.

2.19 Zero-Crossing Detection

An attached UNI-3 motor drive board contains logic that can send out pulses when the
phase voltage of an attached 3-phase motor drops to zero. The motor drive board circuits
generate a 0 to +3.3V DC pulse via voltage comparators. The resulting pulse signals are
sent to a set of jumper blocks shared with the Encoder/Hall-Effect interface. The jumper
blocks allow the selection of Zero-Crossing signals or Quadrature Encoder/Hall-Effect
signals. When in operation, the controller will only monitor one set of signals,
Encoder/Hall-Effect or Zero-Crossing.
Encoder/Hall circuits.
ZERO_X_A
ZERO_X_B
ZERO_X_C
+5.0V
J23
1
2
3
4
5
6
PIN 1: +5.0V
PIN 2: GROUND
PIN 3: PHASE A
PIN 4: PHASE B
PIN 5: INDEX
PIN 6: HOME
Figure 2-16. Zero-Crossing Encoder Interface
MOTOROLA
Freescale Semiconductor, Inc.
contains the primary encoder interface. The secondary
Figure 2-16
FILTER
FILTER
FILTER
FILTER
Technical Summary
For More Information On This Product,
Go to: www.freescale.com
Zero-Crossing Detection
contains the Zero-Crossing and
JG12
1
2
3
4
5
6
7
8
9
56F805
PHASEA0
PHASEB0
INDEX0
HOME0
2-21