The module contains a single Light Emitting Diode (LED) as its light source. The light is colli-mated into a parallel beam by means of a single lens located directly over the LED. Opposite the emitter is the integrated de-tector circuit. This IC consists of multiple sets of photodetectors and the signal processing cir-cuitry necessary to produce the analog waveforms.
The codewheel/codestrip moves between the emitter and detector, causing the light beam to be in-terrupted by the pattern of spaces and bars on the codewheel/ codestrip. The photodiodes which detect these interruptions are arranged in a pattern that corre-sponds to the radius and count density of the codewheel/ codestrip. These detectors are also spaced such that a light period on one pair of detectors corresponds to a dark period on the adjacent pair of detectors. The photodiode outputs are fed through the signal processing circuitry, which produces the final outputs for channels A and B. Due to this integrated phasing technique, the analog output of channel A is in quadrature with channel B (90 degrees out of phase).Package Dimensions
See HEDS-9700 datasheet for
package outline drawings.
Definitions
Count (N): The number of bar
and window pairs or Counts Per
Revolution (CPR) of the code-
wheel, or the number of Lines Per
Inch (LPI) of the codestrip.
1 Shaft Rotation=360 mechanical
degrees
=N cycles
1 cycle (c)=360 electrical
degrees (°e)
= 1 bar and window pair
Pulse Width (P): The number of
electrical degrees that an output
is high during one cycle. This
value is nominally 180°e or 1/2
cycle.
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 four 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 (Φ): The number of elec-
trical degrees between the center
of the high state of channel A and
the center of the high state of
channel B. This value is nomi-
nally 90°e for quadrature output.
Phase Error (?Φ): The devia-
tion of the phase from its ideal
value of 90°e.
Direction of Rotation: When
the codewheel rotates counter-
clockwise, as viewed looking
down on the module (so the
marking is visible), channel A will
lead channel B. If the codewheel
rotates in the opposite direction,
channel B will lead channel A.
Optical Radius (R OP): The
distance from the codewheel’s
center of rotation to the optical
center (O.C.) of the encoder
module.
Mounting Position (R M):
Distance from Motor Shaft center
of rotation to center of Alignment
Tab receiving hole.
Absolute Maximum Ratings
Parameter Symbol Min.Max.Units Notes Storage Temperature T S–4085°C
Operating Temperature T A1545°C
Supply Voltage V CC–0.57V
Soldering Temperature260°C t ≤ 5 sec.
Recommended Operating Conditions
Parameter Symbol Min.Max.Units Notes Temperature T1545
Supply Voltage V CC 4.8 5.2V Ripple < 100 mV p-p Count Frequency8kHz(Velocity (rpm) x N) 60
Waveform Definition
ANALOG
Iap Ibp
A
B
Iam
DIGITAL
A
B
Name Paramenter Definition Label Analog Peak The absolute value in μA of the magnitude of the Iap, Ibp,
analog signal (i.e., one-sided reading).Iam, Ibm Analog Peak-to-Peak Ipp The peak-to-peak signal magnitude in μA of the Iapp
analog signal.Ibpp Analog Offset Ioffset The offset in μA from the mid-point of the analog
peak-to-peak signal to the zero current point.
State Width State Width The number of electrical degrees between a transition State 1
in channel A and the neighboring transition in channel B.State 2
There are four states per cycle, each nominally 90°e.State 3
The transitions are determined by where the analog State 4
signal crosses the Zero point.
State Width Error State Width Error The deviation, in electrical degrees, of each state width
from its ideal value of 90°e.
Pulse Width Pulse Width The number of electrical degrees that an analog output P
is greater than zero during one cycle. This value is
nominally 180°e or 1/2 cycle.
Pulse Width Error Pulse Width Error The deviation, in electrical degrees, of each pulse width
from its ideal value of 180°e.
Electrical Characteristics
Electrical Characteristics over Recommended Operating Range, Typical at 25°C.
Parameter Symbol Min.Typ.Max.Units Notes Supply Current I CC1740mA
Encoding Characteristics
Encoding Characteristics over Recommended Operating Range and Recommended Mounting Tolerances.
These characteristics do not include codewheel/codestrip contributions.
Units
Radial microns± 130
Tangential microns± 130
Gap microns50 – 250 Temperature°C15 – 45
O.R.mm18 – Linear
CPR count900 – Linear Codewheel Slot/Spoke ratio0.9 – 1.1
Min.Max.
IppμA1073
IoffsetμA–4+4
State Width Error e°–40+40
Pulse Width Error e°–40+40 Recommended Codewheel and Codestrip Characteristics
Analog Encoder Interface Circuit
I
A
I
B
V REF = 1.4 V ± 0.2 V (DC)The circuit shown can be used to convert the current output to a voltage. Resistor value, R1, and Capacitor, C, are specified to attain required gain and low-pass filtering, which are application specific. The gain is chosen to attain maximum output swing and not clamp the op-amp. V REF should be set to 1.4 V ± 0.2 V.
A 0.1 μF bypass capacitor (decoupling capacitor) is recom-mended to be placed within 1 cm of the encoder for optimal power supply noise rejection. Outputs are high impedance (typical 1
M ohm) and susceptible to EMI.
Ordering Information HEDS-971
Lead Configurations
0 – straight leads
1 – bent leads
Resolutions
R – 200 lpi
Option
Bracket Options
50
51
Package Dimensions Option 50
Package Dimensions Option 51
FOR DETAILS)
C H B
V C C
C H A
G N D
LEAD THICKNESS = 0.25 mm LEAD PITCH = 2.54 mm
C H B
V C C
C H A
G N D
LEAD THICKNESS = 0.25 mm LEAD PITCH = 2.54 mm
FOR DETAILS)
Package Dimensions Bent Version – Option 50
Package Dimensions Bent Version – Option 51
LEAD THICKNESS = 0.25 mm LEAD PITCH = 2.54 mm
FOR DETAILS)
LEAD THICKNESS = 0.25 mm LEAD PITCH = 2.54 mm
FOR DETAILS)
Mounting Considerations
Note: These dimensions include shaft end play and codewheel warp.
All dimensions for mounting the module and codewheel/codestrip should be measured with respect to the two mounting posts, shown above.
Mounting Tolerances
Case 1 specifies the mounting tolerances required on Rm in order to achieve the respective encoding characteristics shown on page 4. The mounting tolerances are as follows:
Case 1: Rm ± 0.13 mm (.005 inches)
Recommended Screw Size: M2.5 x 0.45 or 2-56
https://www.wendangku.net/doc/ba6724725.html,/semiconductors
For product information and a complete list of
distributors, please go to our web site.
For technical assistance call:
Americas/Canada: +1 (800) 235-0312 or
(408) 654-8675
Europe: +49 (0) 6441 92460
China: 10800 650 0017
Hong Kong: (+65) 6271 2451
India, Australia, New Zealand: (+65) 6271 2394
Japan: (+81 3) 3335-8152(Domestic/Interna-
tional), or 0120-61-1280(Domestic Only)
Korea: (+65) 6271 2194
Malaysia, Singapore: (+65) 6271 2054
Taiwan: (+65) 6271 2654
Data subject to change.
Copyright ? 2002 Agilent Technologies, Inc.
Obsoletes 5988-3614EN
May 10, 2002