TEA3718 TEA3718S STEPPER MOTOR DRIVER ADVANCE DAT A HALF-STEP AND FULL-STEP MODE BIPOLAR DRIVE OF STEPPER MOTOR FOR MAXIMUM MOTOR PERFORMANCE BUILT-IN PROTECTION DIODES WIDE RANGE OF CURRENT CONTROL 5 TO 1500 mA WIDE VOLTAGE RANGE 10 TO 50 V DESIGNED FOR UNSTABILIZED MOTOR SUPPLY VOLTAGE CURRENT LEVELS CAN BE SELECTED IN STEPS OR VARIED CONTINUOUSLY THERMAL OVERLOAD PROTECTION ALARM OUTPUT OR PRE-ALARM OUTPUT (see internal table) Powerdip 12 + 2 + 2 SO-20 ORDERING NUMBERS : TEA3718SDP TEA3718DP ORDERING NUMBER : TEA3718SFP MULTIWATT-15 DESCRIPTION TheTEA3718 and TEA3718Sare bipolar monolithic integrated circuits intended to control and drive the current in one winding of a bipolar stepper motor. The circuits consist of an LS-TTL compatible logic input, a current sensor, a monostable and an output stage with built-in protection diodes. Two TEA3718 or TEA3718S and a few external components form a complete control and drive unit for LS-TTL or microprocessor-controlled stepper motor systems. ORDERING NUMBER : TEA3718SP PIN CONNECTIONS (top views) TEA3718SP (Multiwatt-15) December 1991 TEA3718SFP (SO-20) TEA3718DP TEA3718SDP (Powerdip 12+2+2) 1/16 This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice. TEA3718-TEA3718S BLOCK DIAGRAM TEA3718S BLOCK DIAGRAM TEA3718 2/16 TEA3718-TEA3718S PIN FUNCTIONS Name Fu nctio n OUT B Output Connection (with pin OUTA). The output stage is a ”H” bridge formed by four transistors and four diodes suitable for switching applications. PULSE TIME A parallel RC network connected to this pin sets the OFF time of the lower power transistors. The pulse generator is a monostable triggered by the rising edge of the output of the comparators (toff = 0.69 R TCT). VS(B) Supply Voltage Input for Half Output Stage GND Ground Connection. In SO-20L and Powerdip these pins also conduct heat from die to printed circuit copper. VSS Supply Voltage Input for Logic Circuitry IN1 This pin and pin IN0 are logic inputs which select the outputs of three comparators to set the current level. Current also depends on the sensing resistor and reference voltage. See truth table. PHASE This TTL-compatible logic input sets the direction of current flow through the load. A high level causes current to flow from OUT A (source) to OUT B (sink). A Schmitt trigger on this input provides good noise immunity and a delay circuit prevents output stage short circuits during switching. IN0 See INPUT 1 COMPARATOR INPUT Input connected to the three comparators. The voltage across the sense resistor is feedback to this input through the low pass filter RCCC. The lower power transistor are disabled when the sense voltage exceeds the reference voltage of the selected comparator. When this occurs the current decays for a time set by RTCT, Toff = 0.69 RTCT. REFERENCE A voltage applied to this pin sets the reference voltage of the three comparators. Reference voltage with the value of RS and the two inputs IN0 and IN1 determines the output current. VS(A) OUT A SENSE RESISTOR ALARM PRE-ALARM Supply voltage input for half output stage See pin OUT B Connection to lower emitters of output stage for insertion of current sense resistor When Tj reaches T1°C the alarm output becomes low (TEA3718SP) When Tj reaches T2°C the prealarm output becomes low (T2<T1) (TEA3718SFP) 3/16 TEA3718-TEA3718S ABSOLUTE MAXIMUM RATINGS Symbol Parameters Valu e Un it 7 50 V V Input Voltage: Logic Inputs Analog Inputs Reference Input 6 VSS 15 V V V Input Current Logic Inputs Analog Inputs -10 -10 mA mA Supply Voltage VSS VS VI ii IO Output Current ±1.5 A TJ Junction Temperature +150 °C Top Operating Ambient Temperature Range 0 to 70 °C Tstg Storage Temperature Range -55 to +150 °C THERMAL DATA Symb ol Rth(j-c) Parameter SO -20L Maximum Junction-case Thermal Resistance Rth(j-a) Maximum Junction-ambient Thermal Resistance Po werdip Mu lt iwatt 16 11 3 60 * 45 * 40 Uni t °C/W °C/W * Soldered on a 35 µm thick 4 cm PC board copper area. 2 RECOMMENDED OPERATING CONDITIONS Symb ol Min . T yp. Max. Unit vss Supply Voltage Parameter 4.75 5 5.25 V VS Supply Voltage 10 – 45 V im Output Current 0.020 – 1.2 A 70 °C Tamb Ambient Temperature 0 tr Rise Time Logic Inputs – – 2 µs tf Fall Time Logic Inputs – – 2 µs COMPARISON TABLE 4/16 Device Current Package TEA3718SDP 1.5A Powerdip 12+2+2 Alarm not connected Pre-Alarm TEA3718SFP 1.5A SO-20L x TEA3718SP 1.5A Multiwatt-15 X TEA3718DP 1.5A Powerdip 12+2+2 not connected TEA3718-TEA3718S MAXIMUM POWER DISSIPATION Figure 1. Figure 2. RS = 1 Ω INDUCTANCE FREE RC = 470 Ω CC = 820 pF CERAMIC Rt = 56 kΩ Ct = 820 pF CERAMIC P = 500 Ω R2 = 1 K 5/16 TEA3718-TEA3718S ELECTRICAL CHARACTERISTICS (VCC = 5V, ± 5%, Vmm = 10V to 45V, Tamb = 0 to 70°C (Tamb = 25°C for TEA3718FP/SFP) unless otherwise specified) Symbo l Min . T yp. Max. Unit ICC Supply Current Parameter - - 25 mA VIH High Level Input Voltage - Logic Inputs 2 - - V VIL Low Level Input Voltage - Logic Inputs - - 0.8 V IIH High Level Input Current - Logic Inputs - - 20 µA IIL Low Level Input Current - Logic Inputs (VI = 0.4V) VCH VCM VCL Comparator Thershold Voltage (VR = 5V) ICO Comparator Input Current I1 = 0 I1 = 0 I1 = 1 IO = 0 IO = 0 IO = 0 -0.4 - - mA 390 230 65 420 250 80 440 270 90 mV mV mV -20 - 20 µA Ioff Output Leakage Current (I O = 0, I1 = 1 Tamb = 25°C - - 100 µA Vsat Total Saturation Voltage Drop (Im = 1A) - - 2.8 3.2 V V Ptot Total Power Disssipation - Im = 1A, fs = 30KHz toff Cut off Time (see figure 1 and 2, Vmm = 10V, Vton > 5µs td Turn off Delay (see fig. 1 and 2, Tamb = 25°C, dVC/dt>50mV/µs) SO20/Powerdip Multiwatt 3.1 3.6 W 30 35 ms - 1.6 - µs Vsat Alarm Output Saturation Voltage - IO = 2mA - 0.8 - V Iref Reference Input Current, VR = 5V - 0.4 1 mA Vsat Source Diode Transistor Pair Saturation Powerdip Im = 0.5A Voltage Powerdip Im = 1A - 1.05 1.35 1.2 (1.3) 1.5 (1.7) V V Multiwatt Im = 0.5A Multiwatt Im = 1A - - 1.3 1.7 V V If = 0.5A If = 1A - 1.1 1.25 1.5 (1.6) 1.7 (1.9) V V Vf Diode Forward Voltage Isub Substrate Leakage Current Vsat Sink Diode Transistor Pair Saturation Voltage Vf Diode Forward Voltage Notes: (...) Only for TEA3718SFP mounted in SO-20L package. 6/16 (Multiwatt) 25 - - 5 mA Powerdip Im = 0.5A Powerdip Im = 1A If = 1A - 1 1.2 1.2 (1.3) 1.3 (1.5) V V Multiwatt Im = 0.5A Multiwatt Im = 1A - - 1.3 1.5 V V If = 0.5A If = 1A - 1 1.1 1.4 (1.6) 1.5 (1.9) V V TEA3718-TEA3718S 7/16 TEA3718-TEA3718S FUNCTIONAL BLOCKS Figure A: ALARM OUTPUT (TEA3718SP - TEA3718DP) TEA3718 Figure B: PRE-ALARM OUTPUT (TEA3718SDP - TEA3718SFP) TEA3718S 8/16 TEA3718-TEA3718S ALARM OUTPUTS (TEA3718SP - TEA3718DP) The alarm output becomes low when the junction temperature reaches T°C. When an alarm condition occours, parts of the supply voltage (dividing bridge R - RC) is fed to the comparator input pin (Fig. A) Depending of the RCC value the behaviour of the circuit is different on alarm condition: For several Multiwatt packages a common detection can be obtained as in Fig. D 1) RC > 80Ω ⇒ the output stage is switched off PRE-ALARM OUTPUT When the junction temperature reaches T1°C (typ. = 170°C) a prealarm signal is generated. 2) RC > 60Ω ⇒ the current in the motor windings is reduced according to the approximate formula: (see also fig. E and F) Im = with VTH = Threshold of the comparator (VCH, VCM, VCL) R = 700Ω (typical) Soft thermal protection occours when function temperature reaches T2 (T2 > T1) VTH VCC RC − • RS R + RC RS Figure C: Alarm Detection for Powerdip Package Figure D: CommonDetection for Several Multiwatt Package 9/16 TEA3718-TEA3718S Figure E: (typical curve) Current Reduction in the Motor on Alarm Condition. Figure F: (Vref 5V) Block Diagram for Half Current on Alarm Condition. Notes: 1. Resistance values given here are for the Vch threshold. They should be adjusted using other comparators threshold or other Vref value. TYPICAL APPLICATION Phase A IN0A IN1A Phase B IN0B IN1B 10/16 TEA3718-TEA3718S FUNCTIONAL DESCRIPTION The circuit is intended to drive a bipolar constant current through one motor winding. The constant current is generated through switch mode regulation. Thereis a choice of threedifferent current levelswith the two logic inputs lN0 and lN1. The current can also be switched off completely. INPUT LOGIC If any of the logic inputs is left open, the circuit will treat it as a high level input. IN0 IN1 H L H L H H L L Current Level No Current Low Current Medium Current Maximum Current PHASE - This input determines the direction of current flow in the winding, depending on the motor connections. The signal is fed through a Schmidttrigger for noise immunity, and through a time delay in order to guarantee that no short-circuit occurs in the output stage during phase-shift. High level on the PHASE input causes the motor current flow from Out A through the winding to Out B. lH0 and lH1 - The current level in the motor winding is selected with these inputs. The values of the different current levels are determined by the reference voltage VR togetherwith the value of the sensing resistor RS. CURRENT SENSOR The single pulse switches off the power feed to the motor winding, causing the winding current to decrease during toff. If a new trigger signal should occur during toff, it is ignored. OUTPUT STAGE The output stage contains four Darlington transistors and four diodes, connected in an H-bridge. The two sinking transistors are used to switch the power supplied to the motor winding, thus driving a constant current through the winding. It should be noted however, that it is not permitted to short circuit the outputs. VSS, VS, VR The circuit will stand any order of turn-on or turn-off the supply voltages VSS and VS. Normal dV/dt values are then assumed. Preferably, VR should be trackingVSS during poweron and power-off if VS is established. ANALOG CONTROL The current levels can be varied continuously if VR is varied with a circuit varying the voltage on the comparator terminal. POWER LOSSES VS OUTPUT CURRENT This part contains a current sensing resistor (RS), a low pass filter (RC, CC) and three comparators. Only one comparator is active at a time. It is activated by the input logic according to the current level chosen with signals IN0 and IN1. The motor current flows through the sensing resistor RS. When the current has increased so that the voltage across RS becomes higher than the reference voltage on the other comparator input, the comparator outputgoes high, which triggers the pulse generator and its output goes high during a fixed pulse time (toff), thus switching off the power feed to the motor winding, and causing the motor current to decrease during toff. SINGLE-PULSE GENERATOR The pulse generator is a monostable triggered on the positive going edge of the comparator output. The monostableoutputis high during thepulsetime, toff, which is determined by the timing components Rt and Ct. toff = 0.69 ⋅ Rt Ct 11/16 TEA3718-TEA3718S PRINCIPAL OPERATING SEQUENCE APPLICATION NOTES MOTOR SELECTION Some stepper motors are not designed for continuous operation at maximum current. As the circuit drives a constant current through the motor, its temperature might increase exceedinglyboth at low and high speed operation. Also, some stepper motors have such high core losses that they are not suited for switch mode current regulation. UNUSED INPUTS Unused inputs shouldbe connectedto proper voltage levels in order to get the highest noise immunity. 12/16 INTERFERENCE As the circuit operates with switch mode current regulation, interference generation problems might arise in some applications. A good measure might then be to decouple the circuit with a 15 nF ceramic capacitor, located near the packagebetween power line VS and ground. The ground lead between RS, CC and circuit GND should be kept as short as possible. This applies also to the lead between the sensing resistor RS and point S, see FUNCTIONAL BLOCKS. TEA3718-TEA3718S MULTIWATT15 PACKAGE MECHANICAL DATA mm DIM. MIN. TYP. inch MAX. MIN. TYP. MAX. A 5 B 2.65 0.104 C 1.6 0.063 D 0.197 1 0.039 E 0.49 0.55 0.019 0.022 F 0.66 0.75 0.026 0.030 G 1.02 1.27 1.52 0.040 0.050 0.060 G1 17.53 17.78 18.03 0.690 0.700 0.710 H1 19.6 0.772 H2 L 20.2 0.795 21.9 22.2 22.5 0.862 0.874 L1 21.7 22.1 22.5 0.854 0.870 L2 17.65 18.1 0.695 L3 17.25 17.5 17.75 0.679 0.689 L4 10.3 10.7 10.9 0.406 0.421 L7 2.65 2.9 0.104 M 4.25 4.55 4.85 0.167 0.179 M1 4.63 5.08 5.53 0.182 0.200 S 1.9 2.6 0.075 0.886 0.886 0.713 0.699 0.429 0.114 0.191 0.218 0.102 S1 1.9 2.6 0.075 0.102 Dia1 3.65 3.85 0.144 0.152 13/16 TEA3718-TEA3718S POWERDIP 16 PACKAGE MECHANICAL DATA mm DIM. MIN. a1 0.51 B 0.85 b b1 TYP. MAX. MIN. TYP. MAX. 0.020 1.40 0.033 0.50 0.38 0.055 0.020 0.50 D 0.015 0.020 20.0 0.787 E 8.80 0.346 e 2.54 0.100 e3 17.78 0.700 F 7.10 0.280 I 5.10 0.201 L Z 14/16 inch 3.30 0.130 1.27 0.050 TEA3718-TEA3718S SO20 PACKAGE MECHANICAL DATA mm DIM. MIN. TYP. A a1 inch MAX. MIN. TYP. 2.65 0.1 0.104 0.3 a2 MAX. 0.004 0.012 2.45 0.096 b 0.35 0.49 0.014 0.019 b1 0.23 0.32 0.009 0.013 C 0.5 0.020 c1 45 (typ.) D 12.6 13.0 0.496 0.512 E 10 10.65 0.394 0.419 e 1.27 0.050 e3 11.43 0.450 F 7.4 7.6 0.291 0.299 L 0.5 1.27 0.020 0.050 M S 0.75 0.030 8 (max.) 15/16 TEA3718-TEA3718S Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectronics. 1994 SGS-THOMSON Microelectronics - All Rights Reserved MULTIWATT is a Registered Trademark of the SGS-THOMSON Microelectronics SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands - Singapore Spain - Sweden - Switzerland - Taiwan - Thaliand - United Kingdom - U.S.A. 16/16