HEDR-5120#H12 Avago Technologies US Inc., HEDR-5120#H12 Datasheet - Page 3

• Manufacturer Part Number: HEDR-5120#H12
• Description: Encoders 2 Channel 408CPR
• Manufacturer: Avago Technologies US Inc.
• Type: Optical Encoderr

Specifications of HEDR-5120#H12

• Number Of Channels: 2
• Product: Optical
• Size / Dimension: 6 mm
• Pulses Per Revolution: 400 CPR
• Detents: No
• Motion: Rotary
• Mounting Style: Surface Mount
• Index Output: Not Indexed
• Encoder Signal: Digital Square Wave
• Built In Switch: No
• Shaft Style: Hollow
• Shaft Diameter (mm): 6mm
• Operating Supply Voltage (typ): 5VDC
• Operating Temperature Min Deg. C: -10C
• Operating Temperature Max Deg. C: 85C
• Terminal Type: Gull Wing
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

photodetector IC with a set of
uniquely configured photodiodes,
a pair of lenses, and a codewheel.
The lens over the LED focuses
light onto the codewheel. Light is
either reflected or not reflected
back to the lens over the
photodetector IC.
As the codewheel rotates an
alternating pattern of light and
dark corresponding to the pattern
of the codewheel falls upon the
photodiodes. This light is used to
produce internal signals A and
A, and B and B. As part of this
“push-pull” detector system, these
signals are fed through
comparators that are part of the
signal processing circuitry to
produce the final outputs for
channels A and B.
Block Diagram
3
CH A
CH B
GND
V
4
2
CC
3
1
PROCESSING
CIRCUITRY
SIGNAL
R
LED
Definitions
Count (N): The number of bar
and window pairs or counts per
revolution (CPR) of the
codewheel.
One Cycle (C): 360 electrical
degrees ( e), 1 bar and window
pair.
Cycle Error ( C): An indication
of cycle uniformity. The
difference between an observed
shaft angle which gives rise to
one electrical cycle and the
nominal angular increment of 1/N
of a revolution.
One Shaft Rotation: 360
mechanical degrees, N cycles.
CODEWHEEL
Position Error (
normalized angular difference
between the actual shaft position
and the position indicated by the
encoder cycle count.
Pulse Width (P): The number of
electrical degrees that an output
is high during one cycle,
nominally 180 e or
Pulse Width Error ( P): The
deviation in electrical degrees of
the pulse width from its ideal
value of 180 e.
State Width (S): The number of
electrical degrees between a
transition in the output of
channel A and the neighboring
transition in the output of
channel B. There are 4 states per
cycle, each nominally 90 e.
State Width Error ( S): The
deviation in electrical degrees of
each state width from its ideal
value of 90 e.
Phase (ø): The number of
electrical degrees between the
center of the high state on
channel A and the center of the
high state on channel B. This
value is nominally 90 e for
quadrature output.
Phase Error ( ø): The deviation
in electrical degrees of the phase
from its ideal value of 90 e.
Direction of Rotation: When
the codewheel rotates in the
counter-clockwise direction (as
viewed from the encoder end of
the motor), channel A will lead
channel B. If the codewheel
rotates in the clockwise direction,
channel B will lead channel A.
1
/
): The
2
a cycle.