MOTOR DRIVER. TEA3718 Datasheet
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
WIDE VOLTAGE RANGE 10 TO 50 V
DESIGNED FOR UNSTABILIZED MOTOR
CURRENT LEVELS CAN BE SELECTED IN
STEPS OR VARIED CONTINUOUSLY
THERMAL OVERLOAD PROTECTION
ALARM OUTPUT OR PRE-ALARM OUTPUT
(see internal table)
DE S CRI P T IO N
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 mi-
croprocessor-controlled stepper motor systems.
PIN CONNECTIONS (top views)
STEPPER MOTOR DRIVER
ADVANCE DAT A
12 + 2 + 2
ORDERING NUMBERS : ORDERING NUMBER :
ORDERING NUMBER : TEA3718SP
(S O- 2 0 )
This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice.
BLOCK DIAGRAM TEA3718S
BLOCK DIAGRAM TEA3718
Fu nctio n
Output Connection (with pin OUTA). The output stage is a ”H” bridge formed by four
transistors and four diodes suitable for switching applications.
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 RTCT).
Supply Voltage Input for Half Output Stage
Ground Connection. In SO-20L and Powerdip these pins also conduct heat from die
to printed circuit copper.
Supply Voltage Input for Logic Circuitry
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.
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.
See INPUT 1
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
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.
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)