TEA3717

TEA3717 STMICROELECTRONICS | Alldatasheet

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Technical content

.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

DESCRIPTION

The TEA3717 is a bipolar monolithic integratedcir- cuit intended to control and drive the current in one winding of a bipolar stepper motor. The circuit con- sists of an LS-TTL compatible logic input, a current sensor, amonostableand an outputstage with built- in protectiondiodes.Two TEA3717and a few exter- nal components form a complete control and drive unit for LS-TTL or microprocessor-controlled step- per motor systems. PIN CONNECTION (top view) POWERDIP 12 + 2 + 2 ORDER CODE : TEA3717DP

Symbol Parameter Value Unit Vmm Power Supply Voltage (pins 14, 3) 45 V VCC Logic Supply Voltage (pin 6) 7 V Vin Vin VV Input Voltage Logic Inputs Analog Inputs Reference Input – 0.5 to 6 V CC V Iin Iin Input Current Logic Inputs Analog Inputs –1 0 –1 0 mA IO Output Current ± 1A Tj Junction Temperature + 150 °C Tstg Storage Temperature Range – 55 to + 150 °C Toper Operating Ambiant Temperature Range 0 to + 70 °C THERMAL DATA Symbol Parameter Value Unit R th (j-c) Maximum Junction-pins Thermal Resistance 11 °C/W R th (j-a) Maximum Junction-ambient Thermal Resistance 45* °C/W * Soldered on a 35 mm thick 20 cm3 PC board copper area SCHEMATIC DIAGRAM RECOMMENDED OPERATING CONDITIONS Symbol Parameter Min. Typ. Max. Unit VCC Supply Voltage 4.75 5 5.25 V Vmm Supply Voltage 10 – 40 V Io Output Current 0.020 – 0.8 A Tamb Ambient Temperature 0 – 70 °C tr Rise Time, Logic Inputs – – 2 µs tf Fall Time, Logic Inputs – – 2 µs TEA3717

ELECTRICAL CHARACTERISTICS

VCC = 5V,±5%, Vmm = + 10V to + 40V, Tamb =0 oCt o+7 0oC (unless otherwise specified) Symbol Parameter Min. Typ. Max. Unit ICC Supply Current – – 25 mA 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), I0 =0 ,I1 =0 I0 =1 ,I1 =0 I0 =0 ,I1 =1 390 230 420 250 440 270 mV ICO Comparator Input Current – 20 – 20 µA Ioff Output Leakage Current (I0 =1 ,I1 =1 ) Tamb =+2 5 °C Tamb =+7 0 °C, VS = 40V, VSS =5 V 100 100 200 µA Vsat Total Saturation Voltage Drop (Io = 500mA) – – 4.0 V Ptot Total Power Dissipation Io = 500mA, fs = 30kHz Io = 800mA, fs = 30kHz 1.8 3.7 2.3 W toff Cut off Time (see figure 1 and 2, Vmm = + 10V, ton ≥ 5µs) 25 30 35 µs td Turn off Delay (see figure 1 and 2, Tamb =+2 5 °C, dVC/dt≥ 50mV/µs) – 1.6 µs Figure 2.Figure 1(see note) TEA3717

The circuit is intentedtodrive a bipolar constantcur- rent through one motor winding. The constant cur- rent is generated through switch mode regulation. Thereis achoice ofthree differentcurrentlevels with the two logic inputs l 0 and l1. 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. I0 I1 Current Level H L H L H H L L No Current Low Current Medium Current Maximum Current PHASE − This input determines the direction of cur- rent flow in the winding, depending on the motor connections. The signal is fed through a Schmidt- trigger 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 M A through the winding to MB. l0 and l1 − The current level in the motor winding is selected with these inputs. The values of the differ- ent current levels are determined by the reference voltage V R togetherwith the value of the sensing re- sistor RS. CURRENT SENSOR This part contains a current sensing resistor (RS), a low passfilter (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 l 0 and l1. The motor current flows through the sensing resistor RS. When the current has increased so that the voltage across RS be- comes higher than the reference voltage on the othercomparatorinput, the comparator outputgoes high, which triggers the pulse generatorand its out- put goes high during a fixed pulse time (t off), 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. Themonostableoutputis highduringthe pulsetime, toff, which is determined by the timing components R tand Ct. toff=0 . 6 9⋅R t C t The single pulse switches off the power feed to the motor winding, causing the winding current to de- crease during toff. If a new trigger signal should occur during toff,i ti s ignored. OUTPUT STAGE The output stage contains four Darlington transis- tors and four diodes, connected in an H-bridge. The two sinking transistors are used to switch the pow- ersupplied to the motor winding, thus driving a con- stant 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 V SS and VS. Normal dV/dt values are then assumed. Preferably,VR shouldbe trackingVCC during power- on and power-off. ANALOG CONTROL The current levels can be varied continuously either if VR is variedor with a circuit varying the voltage fed into the comparator terminal (see fig.1). Note :R S =1 Ω , inductance free R C =1 k Ω C C = 820 pF, ceramic R t =5 6 kΩ C t = 820 pF, ceramic TEA3717

POWERDIP 16 PACKAGE MECHANICAL DATA DIM. mm inch a1 0.51 0.020 B 0.85 1.40 0.033 0.055 b 0.50 0.020 b1 0.38 0.50 0.015 0.020 D 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 3.30 0.130 Z 1.27 0.050 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. Specifica- tions mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information pre- viously 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. TEA3717