TEA3717 STEPPER MOTOR DRIVER .. .. .. . 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 1000 mA WIDE VOLTAGE RANGE 10 TO 45 V DESIGNED FOR UNSTABILIZED MOTOR SUPPLY VOLTAGE CURRENT LEVELS CAN BE SELECTED IN STEPS OR VARIED CONTINUOUSLY POWERDIP 12 + 2 + 2 DESCRIPTION The TEA3717 is a bipolar monolithic integrated circuit intended to control and drive the current in one winding of a bipolar stepper motor. The circuit consists of an LS-TTL compatible logic input, a current sensor, a monostable and an outputstage with builtin protection diodes. Two TEA3717 and a few external components form a complete control and drive unit for LS-TTL or microprocessor-controlled stepper motor systems. ORDER CODE : TEA3717DP PIN CONNECTION (top view) April 1993 1/8 TEA3717 SCHEMATIC DIAGRAM ABSOLUTE MAXIMUM RATINGS Symbol Vmm VCC Vin Vin VV Iin Iin IO Tj Tstg Toper Parameter Power Supply Voltage (pins 14, 3) Logic Supply Voltage (pin 6) Input Voltage Logic Inputs Analog Inputs Reference Input Input Current Logic Inputs Analog Inputs Output Current Junction Temperature Storage Temperature Range Operating Ambiant Temperature Range Value 45 7 Unit V V V – 0.5 to 6 VCC 15 mA – 10 – 10 ±1 + 150 – 55 to + 150 0 to + 70 A °C °C °C Value 11 45* Unit °C/W °C/W THERMAL DATA Symbol Rth (j-c) Rth (j-a) Parameter Maximum Junction-pins Thermal Resistance Maximum Junction-ambient Thermal Resistance * Soldered on a 35 mm thick 20 cm3 PC board copper area RECOMMENDED OPERATING CONDITIONS Symbol VCC Vmm Io Tamb tr tf 2/8 Parameter Supply Voltage Supply Voltage Output Current Ambient Temperature Rise Time, Logic Inputs Fall Time, Logic Inputs Min. 4.75 10 0.020 0 – – Typ. 5 – – – – – Max. 5.25 40 0.8 70 2 2 Unit V V A °C µs µs TEA3717 ELECTRICAL CHARACTERISTICS VCC = 5V, ±5%, Vmm = + 10V to + 40V, Tamb = 0oC to + 70oC (unless otherwise specified) Symbol Parameter Min. Typ. Max. Unit mA ICC Supply Current – – 25 VIH High Level Input Voltage - Logic Inputs 2.0 – – V VIL Low Level Input Voltage - Logic Inputs – – 0.8 V IIH High Level Input Current - Logic Input (VI = + 2.4V) – – 20 µA IIL Low Level Input Current - Logic Inputs (VI = + 0.4V) – 0.4 – – mA VCH VCM VCL Comparator Threshold Voltage (VR = + 5.0V), 390 230 65 420 250 80 440 270 90 mV ICO Comparator Input Current – 20 – 20 µA Ioff Output Leakage Current (I0 = 1, I1 = 1) Tamb = + 25°C Tamb = + 70°C, VS = 40V, V SS = 5V – – – 100 100 200 Vsat Total Saturation Voltage Drop (Io = 500mA) – – 4.0 Ptot Total Power Dissipation Io = 500mA, fs = 30kHz Io = 800mA, fs = 30kHz – – 1.8 3.7 2.3 – toff Cut off Time (see figure 1 and 2, Vmm = + 10V, ton ≥ 5µs) 25 30 35 td Turn off Delay (see figure 1 and 2, Tamb = + 25°C, dVC/dt ≥ 50mV/µs) – 1.6 Figure 1 (see note) I0 = 0, I1 = 0 I0 = 1, I1 = 0 I0 = 0, I1 = 1 µA V W µs µs Figure 2. 3/8 TEA3717 FUNCTIONAL DESCRIPTION The circuit is intented to drive a bipolar constant current through one motor winding. The constant current is generated through switch mode regulation. Thereis a choice of three differentcurrent levels with the two logic inputs l0 and l1. The current can also be switched off completely. othercomparator input, the comparator output goes 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 INPUT LOGIC If any of the logic inputs is left open, the circuit will treat it as a high level input. I0 I1 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 MA through the winding to MB. l0 and l1 − 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 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 l0 and l1. 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 Note : RS = RC = CC = Rt = Ct = 4/8 1 Ω, inductance free 1 kΩ 820 pF, ceramic 56 kΩ 820 pF, ceramic The pulse generator is a monostable triggered on the positive going edge of the comparator output. The monostableoutputis high duringthe pulse time, toff, which is determined by the timing components Rt and Ct. toff = 0.69 ⋅R t Ct 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 t off, 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 powersupplied 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. VCC, Vmm, VR The circuit will stand any order of turn-on or turn-off of the supply voltages VSS and VS. Normal dV/dt values are then assumed. Preferably,VR shouldbe tracking VCC during poweron and power-off. ANALOG CONTROL The current levels can be varied continuously either if VR is varied or with a circuit varying the voltage fed into the comparator terminal (see fig.1). TEA3717 Figure 3 Functional blocks A. TTL compatible input logic B. Current sensor C. Single-pulse generator (monostable) D. Output stage with protection diodes. Figure 4 : Typical Sink Saturation Voltage versus Output Current Figure 5 : Typical Source Saturation Voltage versus Output Current Figure 6 : Typical Power Losses versus Output Current 5/8 TEA3717 TYPICAL APPLICATION Figure 7 : Serial Printer Carriage Drive. Figure 8 : Principal Operating Sequence. 6/8 TEA3717 POWERDIP 16 PACKAGE MECHANICAL DATA mm DIM. MIN. a1 0.51 B 0.85 b b1 TYP. inch MAX. MIN. TYP. MAX. 0.020 1.40 0.033 0.50 0.38 0.020 0.50 D 0.055 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 3.30 0.130 1.27 0.050 7/8 TEA3717 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 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. 8/8