1 features coilb- sensor select coil driver b coil driver a overvoltage and short circuit protection sequencer coilb + coila- coila+ input comp. 1 2 gnd v cc no cross-conduction in either h-bridge divide by 1 and divide by 2 mode guaranteed monotonic on chip flyback diodes fault protection overvoltage load dump protection to 60v package options 8 lead pdip cs8441 stepper motor driver with divide by select 1 gnd coila+ coilae sensor v cc coilb+ coilbe select cs8441 description the cs8441 is a stepper motor driver that implements an h-bridge design in order to drive two coils in an eight step sequence per revolu- tion in the divide by 1 mode; 16 step sequence in the divide by 2 mode. the h-bridge is capable of deliver- ing 85ma to the load. the sequencer insures that the odometer is monotonic. this sequencer is configured such that simultaneous conduction does not occur. before each successive out- put sequence the part is taken through a state where both outputs are turned off individually. this tends to minimize the inductive kick back energy that the part must absorb. on chip clamp diodes are across each output to protect the part from the kick back energy that it must absorb. additional part protection is pro- vided by two functions. the first being ?short circuit protection?. this function will protect the part in the case of a shorted or partially shorted load. the second protection function is the ?overvoltage func- tion?. this function monitors the level of the supply voltage. in tran- sient conditions such as load dump, the part will shut down, protecting itself. block diagram absolute maximum ratings supply voltage (v cc ) (continuous) -40 ? c to +105 ? c ......................?0.5 to 24v (100ms pulse transient) -40 ? c to +105 ? c ..........................?0.5 to 60v input voltage (v in ) ..................................................................?0.3 to v cc +0.3v storage temperature range (t stg ).............................................-65c to 150c junction temperature range.......................................................?40c to 150c esd (human body model) .............................................................................2kv lead temperature soldering wave solder(through hole styles only).............10 sec. max, 260c peak cherry semiconductor corporation 2000 south county trail, east greenwich, ri 02818 tel: (401)885-3600 fax: (401)885-5786 email: info@cherry-semi.com web site: www.cherry-semi.com a company rev. 3/23/00
2 electrical characteristics: unless otherwise stated, these specifications apply for ?40c t a 105c, 6.5v v cc 15.5v. all voltage shall be referenced to gnd unless otherwise noted. overvoltage shutdown of coils occurs when v cc > 16v. parameter test conditions min typ max unit cs8441 * voltage across the coils shall be measured at the specific voltages, but shall also be within linearly interpolated limits. supply, v cc supply voltage range -40c t a 105c 6.5 15.5 vdc -40c t a 25c 6.5 24.0 vdc transient pulse, 100ms 35.0 vdc supply current v cc = 15.5 vdc 24 35 ma outputs not loaded overvoltage shutdown 16 23 v speed sensor input, sensor input frequency range 0.2 1.0 khz switching threshold 1.2 2.4 vdc hysteresis 300 500 mvdc input bias current 0.8vdc v in v cc 0.1 1.0 a input voltage range 0 v cc vdc operating input voltage 10k ? resistor in series -15 vdc to v cc input clamp current i clamp at v in = 0 vdc -0.4 -5.0 ma divider select input, select logic 0 input voltage 100 mvdc logic 1 input voltage 3.0 vdc logic 0 input current 0v v in 100mv -1 -100 a logic 1 input current 3v v in 15.5 vdc 0.75 2.00 ma coil output drivers coil load +25c 198 210 222 ? coil inductance 80 mh coil resistance temperature coefficient 0.35 %/c * energized coil voltage (both polarities) a and b v cc = 6.5 vdc v cc ? 1.5v v cc ? 0.9v vdc v cc = 10.0 vdc v cc ? 1.6v v cc ? 1.0v vdc v cc = 15.5 vdc, ?20c t a 105c v cc ? 1.75v v cc ? 1.1v vdc v cc = 15.5 vdc, ?40c t a ?20c v cc ? 2.0v v cc ? 1.2v vdc de-energized coil leakage 100 a current short circuit protection short circuit threshold 275 400 ma i coil a + i coil b short circuit turn-off delay 5 s
3 figure 2: divide by 1 select mode cs8441 sensor is a pnp comparator input which accepts a sine wave input or a square wave input. this input is protected from excur- sions above v cc as well as any below ground, as long as the cur- rent is limited to 1.5ma. it has an active clamp set to zero volts to prevent negative input voltages from disrupting normal opera- tion. the sensor input can withstand 150v dc as long as the input current is limited to 1.5ma max using a series resistor of 100k ? . simultaneously energizing the source and sink on either leg is not permitted. i.e. q1 & q2 or q3 & q4 cannot be energized simultaneously. circuit function is not affected by inductive transients due to coil loads as specified in transition states section. the transition states occur as indicated in table 1 without any intermediate states permitted. table 1: transition states the polarity definition for the coil driver outputs is as follows: connect connect polarity coil + coil - positive (+) v cc gnd negative (-) gnd v cc the speed sensor input frequency is divided by one or divided by two by connecting the divider select input, (pin 5) as follows: logic 0 = divide by 2 logic 1 = divide by 1 circuit operation speed sensor input coil driver outputs divider select input short circuit v cc sense resistor coil short circuit sense resistor gnd q3 q4 q1 q2 overvoltage and short circuit protection package pin description package pin # pin symbol function figure 1: coil driver output figure 3: divide by 2 select mode output state table state coil a coil b 0++ 1 off + 2-+ 3 - off 4-- 5 off - 6+- 7 + off divide by one mode select = v cc divide by two mode select = gnd 8l pdip 1 gnd ground connection. 2 coila+ output stage, when active, this pin supplies current to coil a. 3 coila- output stage, when active, this pin supplies current to coil a. 4 sensor input signal from wheel speed or engine rpm. 5 select selects divide by 1 or divide by 2 mode. 6 coilb- output stage, when active, this pin supplies current to coil b. 7 coilb+ output stage, when active, this pin supplies current to coil b. 8v cc supply voltage.
4 thermal data 8 lead pdip r jc typ 52 ? c/w r ja typ 100 ? c/w d lead count metric english max min max min 8l pdip 10.16 9.02 .400 .355 package specification package dimensions in mm (inches) ordering information package thermal data rev. 3/23/00 cs8441 part number description CS8441XN8 8 lead pdip coila+ coila coilb+ coilb v cc select gnd sensor cs8441 ign d1 r1 r3 z1 c1 c2 r2 c3 buffered speed signal (open collector drive) coil a coil b odometer application diagram c1 - 10f c2 - 0.1f c3 - 0.01f r1 - 3.9 ? , 500mw r2 - 100k ? r3 - 15k ? d1 - 1a, 600piv z1 - 50v, 500mw coil a - 21012 ? , 80mh coil b - 21012 ? , 80mh 0.39 (.015) min. 2.54 (.100) bsc 1.77 (.070) 1.14 (.045) d some 8 and 16 lead packages may have 1/2 lead at the end of the package. all specs are the same. .203 (.008) .356 (.014) ref: jedec ms-001 3.68 (.145) 2.92 (.115) 8.26 (.325) 7.62 (.300) 7.11 (.280) 6.10 (.240) .356 (.014) .558 (.022) plastic dip (n); 300 mil wide ? 2000 cherry semiconductor corporation cherry semiconductor corporation reserves the right to make changes to the specifications without notice. please contact cherry semiconductor corporation for the latest available information.
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