Order this document by SAA4/D The SAA4 drives a two phase stepper motor in the bipolar mode. The device contains three input stages, a logic section and two output stages. The IC is contained in a pin dual in line heat tab plastic package for improved heatsinking capability. The center four ground pins are connected to the copper alloy heat tab and improve thermal conduction from the die to the circuit board. Drive Stages Designed for Motors:. and : SAA4 ma/coil Drive Capability Built In Clamp Diodes for Overvoltage Suppression Wide Logic Supply oltage Range Accepts Commands for and Half/Full Step Operation Inputs Compatible with Popular Logic Families: MOS, TTL, DTL Set Input Defined Output State Drive Stage Bias Adaptable to Motor Power Dissipation for Optimum Efficiency STEPPER MOTOR DRIER SEMICONDUCTOR TECHNICAL DATA SUFFIX PLASTIC PACKAGE CASE 48C PIN CONNECTIONS Figure. Representative Block Diagram Z D L L 4 M CC Logic M Driver D L M Set/ Driver Bias Full/Half Step 4 8 (Top iew) CC 8 Full/ Half Step Driver Driver Bias RB A Set 4 L Device ORDERING INFORMATION Operating Temperature Range Package SAA4 TJ = to + C Plastic DIP MOTOROLA ANALOG IC DEICE DATA Motorola, Inc. Rev
MAXIMUM RATINGS (TA = C, unless otherwise noted.) SAA4 Rating Symbol SAA4 Unit Clamping oltage (Pins,, 4, ) clamp Over oltage (O = clamp M) O. Supply oltage CC Switching or Motor Current/Coil IM ma Input oltage (Pins, 8, ) Power Dissipation (Note ) Thermal Resistance, Junction to Air Thermal Resistance, Junction to Case in clock in Full/Half in PD θja θjc CC 8 W C/W Operating Junction Temperature Range TJ to + C Storage Temperature Range Tstg to + C NOTE:. The power dissipation (P D ) of the circuit is given by the supply voltage ( M and CC ) and the motor current (I M ), and can be determined from Figures and. P D = P drive P logic. ELECTRICAL CHARACTERISTICS (TA = C, unless otherwise noted.) Characteristics Pin(s) Symbol CC Min Typ Max Unit Supply Current ICC. Motor Supply Current (IPin = 4 µa, Pins,, 4, Open) M =. M = M = 4 IM... Input oltage, High State, 8, IH. Input oltage, Low State IL. Input Reverse Current, High State (in = CC) Input Forward Current, Low State (in = ) Output oltage, High State (M = ) Iout = ma Iout = ma Output oltage, Low State Iout = ma Iout = ma Output Leakage Current, Pin = Open (M = D = clamp max), 8, IIR. IIF.. 4 4,, 4, OH. OL.,, 4, IDR. 4 M M.... 8..8..... ma ma µa µa Clamp Diode Forward oltage (Drop at IM = ma) F.. Frequency fc. khz Pulse Width tw. µs Set Pulse Width ts µs Set Control oltage, High State Set Control oltage, Low State M. MOTOROLA ANALOG IC DEICE DATA
(Pin ) This input is active on the positive edge of the clock pulse and accepts Logic input levels dependent on the supply voltage and includes hysteresis for noise immunity. (Pin ) This input determines the motor s rotational direction. When the input is held low, (O, see the electrical characteristics) the motor s direction is nominally clockwise (CW). When the input is in the high state, Logic, the motor direction is nominally counter clockwise (CCW), depending on the motor connections. Full/Half Step (Pin 8) This input determines the angular rotation of the motor for each clock pulse. In the low state, the motor will make a full step for each applied clock pulse, while in the high state, the motor will make half a step. D (Pin ) This pin is used to protect the outputs (,,4, ) where large positive spikes occur due to switching the motor coils. The maximum allowable voltage on these pins is the clamp voltage (clamp). Motor performance is improved if a zener diode is connected between Pin and, as shown in Figure. The following conditions have to be considered when selecting the zener diode: clamp = M +. Z = clamp M F where: F = clamp diodes forward voltage drop F = (see Figure 4) clamp: for SAA4 for clamp: SAA4A Pins and can be linked, in this case Z =. Set/Bias Input (Pin ) This input has two functions: ) The resistor RB adapts the drivers to the motor current. ) A pulse via the resistor RB sets the outputs (,, 4, ) to a defined state. The resistor RB can be determined from the graph of Figure according to the motor current and voltage. Smaller values of RB will increase the power dissipation of the circuit and larger values of RB may increase the saturation voltage of the driver transistors. When the set function is not used, terminal A of the resistor RB must be grounded. When the set function is used, terminal A has to be connected to an open collector (buffer) circuit. Figure shows this configuration. The buffer circuit (off state) has to sustain the motor voltage (M). When a SAA4 INPUT/OUTPUT FUNCTIONS pulse is applied via the buffer and the bias resistor (RB), the motor driver transistors are turned off during the pulse and after the pulse has ended, the outputs will be in defined states. Figure shows the Timing Diagram. Figure illustrates a typical application in which the SAA4 drives a stepper motor with a current consumption of ma/coil. A bias resistor (RB) of kω is chosen according to Figure. The maximum voltage permitted at the output pin is M +. (see Maximum Ratings table), in this application M =, therefore the maximum voltage is 8. The outputs are protected by the internal diodes and an external zener connected between Pins and. From Figure 4, it can be seen that the voltage drop across the internal diodes is about. at ma. This results in a zener voltage between Pins and of: Z =.. = 4.. To allow for production tolerances and a safety margin, a. zener has been chosen for this example. The clock is derived from the line frequency which is phase locked by the MC44B and the MC44. The voltage on the clock input is normally low (Logic ). The motor steps on the positive going transition of the clock pulse. The Logic applied to the Full/Half input (Pin 8) operates the motor in Full Step mode. A Logic at this input will result in Half Step mode. The logic level state on the input (Pin ), and the connection of the motor coils to the outputs determines the rotational direction of the motor. These two inputs should be biased to a Logic or and not left floating. In the event of non use, they should be tied to ground or the logic supply line, CC. The output drivers can be set to a fixed operating point by use of the Set input and a bias resistor, RB. A positive pulse to this input turns the drivers off and sets the logic state of the outputs. After the negative going transition of the Set pulse, and until the first positive going transition of the clock, the outputs will be: L = L = high and = = low, (see Figure ). The Set input can be driven by a MC4B or a transistor whose collector resistor is RB. If the input is not used, the bottom of RB must be grounded. The total power dissipation of the circuit can be determined from Figures and : PD =. W +.8 W =.8 W. The junction temperature can then be computed using Figure 8. MOTOROLA ANALOG IC DEICE DATA
SAA4 R B BIAS RESISTOR (k Ω ) Figure. Bias Resistor RB versus Motor Current M = M =. M = 4 DRIE STAGE POWER DISSIPATION (W). 4....... Figure. Drive Stage Power Dissipation M = 4 M = M =.. 4 8 4 4 MOTOR CURRENT/COIL (ma) MOTOR CURRENT/COIL (ma) Figure 4. Clamp Diode Forward Current versus Forward oltage Figure. Power Dissipation versus Logic Supply oltage FORWARD CURRENT (ma) 4, POWER DISSIPATION (m) P D.. F, FORWARD OLTAGE () 4... CC, SUPPLY OLTAGE () Figure. Timing Diagram Full Step Motor Drive Mode. Full/Half Step Input = Set L L Don t Care High Output Impedance Half Step Motor Drive Mode. Full/Half Step Input = Set L L 4 MOTOROLA ANALOG IC DEICE DATA
SAA4 Figure. Typical Application Selectable Step Rates with the Time Base Derived from the Line Frequency Z =. Hz k. µf 4 MC44B Phase Comp 8 k 8. µf CO 4. nf k f = 4 Hz 4 MC44 4 Steps/Sec. 4 8 Full Half CW CCW 8 SAA4 4 RB k M Set Input Set MC4 Figure 8. Thermal Resistance and Maximum Power Dissipation versus P.C.B. Copper Length R θja, THERMAL RESISTANCE JUNCTION TO AIR ( C/W) 8 4 RθJA PD(max) for TA = C Printed circuit board heatsink example L oz Copper L. mm Graph represents symmetrical layout 4 L, LENGTH OF COPPER (mm). 4... P D(max), MAXIMUM POWER DISSIPATION (W) MOTOROLA ANALOG IC DEICE DATA
SAA4 OUTLINE DIMENSIONS SUFFIX PLASTIC PACKAGE CASE 48C ISSUE C A B NOTES:. DIMENSIONING AND TOLERANCING PER ANSI Y4.M, 8.. CONTROLLING DIMENSION: INCH.. DIMENSION L TO CENTER OF LEADS WHEN FORMED PARALLEL. 4. DIMENSION B DOES NOT INCLUDE MOLD FLASH.. INTERNAL LEAD CONNECTION BETWEEN 4 AND, AND. T SEATING PLANE F 8 NOTE E G D PL. (.) M T A S N C L J PL. (.) M T B S M INCHES MILLIMETERS DIM MIN MAX MIN MAX A.4.84 8.8.4 B.4... C.4.8. 4. D...8. E. BSC. BSC F.4...8 G. BSC.4 BSC J.8...8 K....4 L. BSC. BSC M N..4.. Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. Typical parameters which may be provided in Motorola data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including Typicals must be validated for each customer application by customer s technical experts. Motorola does not convey any license under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that Motorola was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer. How to reach us: USA / EUROPE / Locations Not Listed: Motorola Literature Distribution; JAPAN: Nippon Motorola Ltd.; Tatsumi SPD JLDC, F Seibu Butsuryu Center, P.O. Box ; Phoenix, Arizona 8. 8 44 44 or 44 4 Tatsumi Koto Ku, Tokyo, Japan. 8 8 MFAX: RMFAX@email.sps.mot.com TOUCHTONE 44 ASIA/PACIFIC: Motorola Semiconductors H.K. Ltd.; 8B Tai Ping Industrial Park, INTERNET: http://design NET.com Ting Kok Road, Tai Po, N.T., Hong Kong. 8 8 MOTOROLA ANALOG IC DEICE SAA4/D DATA