Agilent HEDS-9202 Two Channel Optical Incremental Encoder Modules 200 LPI Analog Output Data Sheet Description The HEDS-9202 is a high-performance, low-cost, optical incremental encoder module. When operated in conjunction with either a codewheel or codestrip, this module detects rotary or linear position. The encoder module consists of a lensed LED source and a detector IC enclosed in a small C-shaped plastic package. Due to a highly collimated light source and a unique photodetector array, the module is extremely tolerant to mounting misalignment. The two channel analog outputs and 5 V supply input are accessed through five 0.025 inch square pins located on 0.1 inch centers. The standard HEDS-9202 is designed for use with an appropriate optical radius codewheel, or linear codestrip. Applications The HEDS-9202 provides sophisticated motion detection at a low cost, making closed-loop control very cost-effective. Typical applications include printers, plotters, copiers, and office automation equipment. Note: Agilent Technologies’ encoders are not recommended for use in safety critical applications, e.g., ABS braking systems, power steering, life support systems, and critical care medical equipment. Please contact sales representatives if more clarification is needed. Theory of Operation The HEDS-9202 is a C-shaped emitter/detector module. Coupled with a codewheel, it translates rotary motion into a two-channel analog output. Coupled with a codestrip, it translates linear motion into analog outputs. The module contains a single Light Emitting Diode (LED) as its light source. The light is collimated into a parallel beam by means of a single lens located directly over Features • Low cost • Multiple mounting options • 200 lpi resolution • Linear and rotary options available • No signal adjustment required • Insensitive to radial and axial play • –10°C to 100°C operating temperature • Two channel analog output • Single 5 V supply • Wave solderable the LED. Opposite the emitter is the integrated detector circuit. This IC consists of multiple sets of photodetectors and the signal processing circuitry necessary to produce the analog waveforms. The codewheel/codestrip moves between the emitter and detector, causing the light beam to be interrupted by the pattern of spaces and bars on the codewheel/ codestrip. The photodiodes which detect these interruptions are arranged in a pattern that corresponds 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). Definitions Count (N) = The number of bar and window pairs or Counts Per Revolution (CPR) of the codewheel, or the number of Lines Per Inch of the codestrip (LPI). 1 Shaft Rotation = 360 mechanical degrees = N cycles 1 cycles (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 (DP): 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 (DS): The deviation, in electrical degrees, of each state width from its ideal value of 90°e. Phase (F): The number of electrical degrees between the center of the high state of channel A and the center of the high state of channel B. this value is nominally 90°e for quadrature output. Phase Error (DF): The deviation of the phase from its ideal value of 90°e. Direction of Rotation: When the codewheel rotates counterclockwise, 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 (Rop): The distance from the codewheel’s center of rotation to the Optical Center (O.C.) of the encoder module. Mounting Position (RM): Distance from Motor Shaft center of rotation to center of Alignment Tab receiving hole. Absolute Maximum Ratings Subjecting the part to stresses beyond those listed under this section may cause permanent damage to the device. These are stress ratings only and it is not implied that devices function beyond these ratings. Exposure to the extremes of these conditions for extended periods may affect device reliability. Parameter Storage Temperature Operating Temperature Supply Voltage Soldering Temperature Symbol TS TA VCC Min. –40 –10 –0.5 Max. 100 100 7 260 Unit ˚C ˚C V ˚C Notes t ≤ 5 sec. Recommended Operating Conditions Parameter Temperature Supply Voltage Count Frequency 2 Symbol T VCC Min. –10 4.8 Typ. 25 5 8 Max. 100 5.2 120 Unit ˚C V kHz Notes Ripple < 100 mVp-p (Velocity (rpm) x N) 60 Waveform Definition ANALOG IBP IAP A B IBM IAM DIGITAL A B P P S1 S2 S3 S4 Name Analog Peak Parameter Analog Peak to Peak IPP Analog Offset IOFFSET State Width State Width Error Pulse Width Pulse Width Error 3 Definition The absolute value, in µA, of the magnitude of the analog signal (i.e., one-sided reading). The peak to peak signal magnitude, in µA, of the analog signal. The offset, in µA, from the mid-point of the analog peak to peak signal to the zero current point. State Width The number of electrical degrees between a transition in channel A and the neighboring transition in channel B. There are 4 states per cycle, each nominally 90°e. The transitions are determined by where the analog signal crosses the Zero point. State Width Error The deviation, in electrical degrees, of each state width from its ideal value of 90°e. Pulse Width The number of electrical degrees that an analog output is greater than zero during one cycle. This value is nominally 180°e or 1/2 cycle. Pulse Width Error The deviation, in electrical degrees, of each pulse width from its ideal value of 180°e. Label IAP, IBP, IAM, IBM IAPP IBPP State 1 State 2 State 3 State 4 P Electrical/Optical Characteristics Electrical Characteristics over Recommended Operating Range, Typical at 25°C. Parameter Supply Current Symbol ICC Min. 16 Typ. 18 Max. 30 Units mA Notes Encoding Characteristics Encoding Characteristics over Recommended Operating Range and Recommended Mounting Tolerances. These characteristics do not include codewheel/codestrip contributions. Units Typ. Radial microns ±400 0 Tangential microns ±500 0 Gap (codewheel from detector surface) microns 50 - 850 250 Temp °C –10 to 100 25 O.R. mm 15 to linear 23.36 CPR count 744 to linear 1156 Codewheel Slot/Spoke ratio .9 - 1.1 1 Min. Max. IPP µA 10 85 60 - 70 IOFFSET µA –4 +4 1 State Width Error e° –40 +40 4 Pulse Width Error e° –40 +40 8 Analog Encoder Interface Circuit VREF I+ + – VA C IA-IN R1 VREF I+ + – VB C 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. VREF should be set to 1.4 V + 0.2 V. A 0.1 µF bypass capacitor is recommended to be placed within 1 cm of the encoder for optimal power supply noise rejection. Outputs are high impedance (typical 1 MΩ) and susceptible to EMI. IB-IN R1 VREF = 1.4 V ± 0.2 V(DC) 4 Ordering Information Device Lead HEDS-9202 straight Resolution R00 (200LPI) Mounting Considerations 0.76 (0.030) HIGH (MAX.) 2.36 (0.093) ± 0.025 (0.001) DIA. 0.26 (0.010) x 45° CHAMFER 10.5 (0.413) 8.64 (0.340) 20.83 (0.820) 21.08 (0.830) 17.17 (0.676) 17.37 (0.684) ROP MOTOR SHAFT CENTER OPTICAL CENTER 1.02 ROP+ (0.040) M 2.5 x 0.45 (2-56 UNC-2B) 2 PLACES 3.63 (0.143) 3.84 (0.151) 4.75 ROP+ (0.187) REF. Figure 1. Mounting plane side A. M 2.5 x 0.45 (2-56 UNC-2B) 2 PLACES OPTICAL CENTER 10.5 (0.413) 20.83 (0.820) 21.08 (0.830) 6.36 (0.250) 12.60 (0.496) 12.80 (0.504) ROP MOTOR SHAFT CENTER ALIGNING BOSS 0.76 (0.030) HIGH (MAX.) 2.36 (0.093) ± 0.025 (0.001) DIA. 0.25 (0.010) x 45° CHAMFER 2 PLACES 4.75 ROP+ (0.187) Figure 2. Mounting plane side B. 5 Package Dimensions 0.215 ± 0.004 0.070 ± 0.004 OPTION CODE OPTICAL CENTER 0.115 ± 0.004 X00 YYWW DATE CODE 1.05 HEDS-9202 0.62 0.187 ± 0.004 ∅ 0.105 MOUNTING THRU HOLE 2 PLCS 0.82 PIN 1 ID PIN 1 – GND PIN 2 – CH I (3 CH ONLY) PIN 3 – CH A PIN 4 – VCC 6 PIN 5 – CH B PART NUMBER 0.07 STANDOFF 0.28 0.025 TYP. 0.53 0.46 www.agilent.com/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/International), 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. July 26, 2002 5988-7441EN