aeds-96ex series small optical encoder modules 200 lpi analog voltage output data sheet description the aeds-96ex is a very small high performance, low cost optical incremental encoder module. when operated in conjunction with a codewheel/codestrip, this module detects rotary/linear position .the encoder module consists of a lensed light emitting diode (led) source and a detector ic enclosed in small c-shaped plastic package. due to highly collimated light source and a unique photodetector array, the module is extremely tolerant to mounting misalignment. the two channel analog outputs and 3.3v supply input are accessed through four leads located on 2.00mm centers for the detector and two leads located on 2.54mm center for the emitter. aeds-96ex is designed for use with an appropriate optical radius codewheel. please contact factory for more information. features ? rohs compliant ? small size ? low cost ? built-in guide bumps for codewheel and codestrip ? low package height ? insensitive to radial, tangential and axial play ? 0c to +60c recommended operating temperature ? two channel analog output ? single 3.3v supply ? wave solderable specifications ? 200 lpi ? 3.3v supply* ? 1.52v led forward voltage (if = 16ma)* * typical conditions applications ? printers ? copiers/fax ? plotters ? office automation equipments
2 theory of operation the aeds-96ex is a c-shaped emitter/detector module. coupled with a codewheel/codestrip, it translates rotary motion into a two-channel analog output. 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 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 pairs of detectors. the photodiode outputs are fed through the signal processing circuitry, which produce the final outputs for channel a and channel 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 degrees = n cycles 1 cycle (c) = 360 electrical degree, equivalent to 1 bar and window pair. 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. line density : the number of window and bar pair per unit length, express in either lines per inch (lpi) or lines per mm (lpmm) optical radius (rop) : the distance from the codewheels center of rotation to the optical center (o.c) of the encoder module. gap (g) : the distance from surface of the encoder to the surface of codewheel or codestrip mounting position (rm) : distance from motor shaft center of rotation to center of alignment tab receiving hole. radial and tangential misalignment error (er and er) : for rotary motion mechanical displacement in the radial and tangential directions relative to the nominal alignment angular misalignment error (ea) : angular misalignment of the sensor in relation to then tangential direction. this applies for both rotary and linear motion.of electrical degrees that an output is high during one cycle, nominally 180e or 1/2 a cycle. aeds-96ex series block diagram a a + e channel a 1 b b + e channel b 3 v cc 2 gnd 4 signal processing circuitry v led 5 gnd 6 led lens photo- diodes pullup resistor 2.5 k x 2 comparators emitter section code wheel detector section
3 recommended operating conditions 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 do not imply that the device functions beyond these ratings. exposure to the extremes of these conditions for extended periods may affect device reliability. electrical characteristics electrical characteristics over recommended operating range, typically at 25c parameter symbol min. max. units notes storage temperature t s -40 85 c operating temperature t a 070c supply voltage (detector) v cc -0.5 7 v output voltage va , vb -0.5 v cc + 0.4 v soldering temperature 260 c t 7 sec dc forward current (led) i led 50 ma vf < 1.8v reverse voltage v r 5 v ir = 100ua parameter symbol min. typ. max. units notes operating temperature t 0 25 60 c supply voltage (detector) v cc 3.15 3.3 3.45 v ripple < 100mvpp output frequency f 8 50 khz (velocity (rpm) x n)/60 dc forward current (led) i led 10 16 20 ma recommended 110 ? (10%) series drop resistor between 3.3v supply and vled. parameter symbol min. typical max. units notes supply current (detector) i cc 58ma led forward voltage v f 1.3 (turn on) 1.5 (operate) 1.52 1.54 v typical i f = 16ma
4 waveform definition encoding characteristics the encoding characteristics stated below are obtained using parallel loading of 100pf capacitor and 100kw resistor parameter symbol mean (a) min (b) max (b) units state width error ? s 6.817 35 e pulse width error ? p 5.421 35 e state x width error ? sx 3.033 25 e pulse x width error ? px 3.370 25 e upper crosspoint voltage vx12, vx34 2.39 1.40 2.60 v lower crosspoint voltage vx56, vx78 1.02 0.80 2.30 v peak to peak voltage vppa vppb 2.13 1.00 3.00 v analog offset voltage voffset a, voffset b -14.52 -150 150 mv *average linearity error ? linearity 3.93 9.25 % ac parameter @3.15 v @3.3v @3.45v vppa (v) 2.100 2.170 2.246 vppb (v) 2.170 2.179 2.252 voffset a (mv) -40.89 -7.41 24.62 voffset b (mv) -44.33 -10.95 21.55 ch a ch b p a p b s 1 s 2 s 3 s 4 s x 1 s x 2 s x 3 s x 4 ch b p x b p xa v x 12 v x 34 v x 56 v x 78 v pp 1.65v voltage offset reference derating characteristics derating table of vpp and voffset at 3.15, 3.3 and 3.45 volts (average of 30 units) note: obtained at typical conditions specified in recommended operating conditions and nominal mounting position (radial, tangential, gap) of (0, 0, 0). notes: * average linearity is the characterized parameter, 2 lines per cycle for each channel for full rotation of the codewheel. a. obtained at typical conditions specified in recommended operating conditions and nominal mounting position (radial, tangential, gap) of (0,0, 0) b. obtained over the whole recommended operating conditions and part mounting tolerances
5 test parameter definitions parameter symbol definition units analog peak voltage vap, vbp, vam, vbm the absolute value in v of the magnitude of the analog signal (i.e. one sided rating) sitting 1.65v voltage offset reference v analog peak to peak voltage vppa vppb the peak to peak signal magnitude in v of the analog signal v analog peak to peak ratio vppa/vppb the ratio of a channel peak analog signal to b channel peak analog signal - analog crossing vx12, vx34, vx56, vx78 the intersection in v of the a channel analog waveform with either the b channel analog waveform or its compliment. v analog offset voltage voffset a voffset b the offset in v from the mid-point of the analog peak to peak signal to 1.65v voltage offset reference mv state width s1, s2, s3, s4 the number of electrical degrees between a transition in channel a and the neighboring transition in channel b. there are 4 state per cycle, each nominally 900e. the transitions are determined by where the analog signal crosses the zero point e state width error ? s1, ? s2, ? s3, ? s4 the deviation in electrical degrees of each state width from its ideal value of 900e. e pulse width pa,pb the number of electrical degrees that an analog output is greater than zero during one cycle. this value is nominally 1800e or ? cycle. e pulse width error p the deviation in electrical degrees of each pulse width from its ideal value of 1800e. e state x width s x1 s x2 s x3 s x4 the number of electrical degree between a transition in channel a and the neighboring transition in channel b. there are 4 state per cycle, each nominally 900e. the transitions are determined by where the a analog signal and b analog signal (or its complement) cross. e state x width error ? s x1 , ? s x2 ? s x3 , ? s x4 the deviation in electrical degrees of each state x width from its nominal value of 900e. e pulse x width p xa p xb pulse x width a is the number of electrical degrees that analog a output is greater than analog b bar output during one cycle. pulse x width b is the number of electrical degrees that analog b is greater than analog a during one cycle. this value is nominally 1800e or ? cycle. e pulse x width error p xa, p xb the deviation in electrical degrees of each pulse x width from its nominal value of 1800e. e max linearity error linearity ratio (in percentage) of maximum voltage deviation from a straight line connecting adjacent upper and lower crosspoint voltages to the difference between crosspoint voltages %
6 mounting configuration note: these dimension includes shaft end play and codewheel warp. all dimensions for mounting in the module and codewheel/codestrip should be measured with respect to the two mounting post shown above. error rop=11.00mm unit notes eg gap 0.15 mm recommend cw to put closer to the detector side (upper side), in order to give enough margin for encoder operation. er radial 0.13 mm et tangential 0.13 mm ea angular 3 deg. r m 2.05 min. 2xr 2.05 hole min . 1.0 deep min. 4.30 (0.169) max 4.50 (0.177) min. r op 4.40 0.15 (0.173 0.006) see note 4.75 (0.187) max. c of alignment tab l r m r op - 2.40 (0.094) e g image side of codewheel / codestrip e t e r e a
7 package dimension AEDS-96E0-R10
8 aeds-96e1-r10 13.7 6.9 3.5 3.5 part # resolution identification date code optical center mark xxxx x 10 0.5 r 1.1 1.4 5.6 11.0 4.1 0.5 2.0 0.5 0.254 (leadframe thickness) 1.8 7.6 2.6 max. external radius r 0.5 4.40 ? 2.00 (2 places) 7.0 0.8 1.0 ayww chamfered lead-in (both sides) (optical center) (emitter) (detector) 1.10 2 e ? 2.10 0.05 4.40 11.0 0.2 13.1 0.2 1.27 2.54 typ. 2.00 typ. 1.00 6 e ? 1.00 mounting footprint ch a ch b v cc gnd v cc gnd xxxx 10 yyww
9 recommended wave solder profile note: - nominal values are evaluated profiles for optimum performance. - min/max are critical limits to ensure encoders in good condition. 120 c/120 sec max cool down reflow 7 sec max 260 c pb-free wave soldering profile std profile 2 time (s) a b c parameter min. max. nominal values units a solder pot temperature na 260 250 - 260 c b preheat zone temperature 85 120 100 - 120 c c dip in time 5 7 5 sec d solder pot zone (encoder lead) 200 260 na c
for product information and a complete list of distributors, please go to our web site: www.avagotech.com avago, avago technologies, and the a logo are trademarks of avago technologies, limited in the united states and other countrie s. data subject to change. copyright ? 2006 avago technologies pte. all rights reserved. av01-0107en - april 19, 2006
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