View TEA3718SFPTR_4915024.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

TEA3718
Stepper motor driver
Features

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 insteps or varied continuously Thermal overload protection Alarm output or pre-alarm output Figure 1. Block diagram
MultiwattTM 15
Power DIP 12+2+2
SO20
Applications
The TEA3718 is a bipolar monolithic integrated circuit intended to control and drive the current in one winding of a bipolar stepper motor.
Motor winding
OUT A OUT B
Description
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 ICs and a few external components form a complete control and drive unit for LS-TTL or microprocessor-controlled stepper motor systems. Table 1. Device summary
Order code E-TEA3718SDP Power DIP E-TEA3718DP E-TEA3718SFP E-TEA3718SFPTR E-TEA3718SP SO20 SO20 (tape and reel) MultiwattTM 15 Package
COMPARATOR INPUT PHASE PULSE TIME IN0 IN1 REFERENCE
TEA3718
ALARM (TEA3718SP) PRE-ALARM (TEA3718SFP) SENSE RESISTOR
TM: Multiwatt is a trademark of STMicroelectronics
January 2009
Rev 2
1/26
www.st.com
26
Pin connections
1
Figure 2.
Pin connections
Package pin locations (top views) E-TEA3718SFP (SO20) E-TEA3718DP E-TEA3718SDP (Power DIP 12+2+2)
E-TEA3718SP (Multiwatt 15)
2/26
Contents
Contents
1 2 3 Pin connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Device diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1 3.2 3.3 3.4 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Recommended operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4
Functional blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.1 4.2 4.3 4.4 Alarm output (TEA3718SP, TEA3718DP and TEA3718SDP) . . . . . . . . . 14 Pre-alarm output (TEA3718SFP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Current reduction in alarm condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Typical application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5
Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.1 5.2 5.3 5.4 5.5 5.6 5.7 Input logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Phase input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Current sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Single-pulse generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Output stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 VSS, VS and VR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Analog control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3/26
Contents
6
Application notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.1 6.2 6.3 6.4 Motor selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Unused inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Operating sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
7
Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4/26
Device diagrams
2
Figure 3.
Device diagrams
Detailed block diagram (TEA3718SFP)
Figure 4.
Detailed block diagram (TEA3718SP)
5/26
Device diagrams Table 2. Pin functions
Name OUTB Function Output connection (with pin OUT A). 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 RT CT). Supply voltage input for half output stage Ground connection. In SO20 and power DIP 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. SeeTable 8: 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 Schmidt trigger on this input provides good noise immunity and a delay circuit prevents output stage short circuits during switching. See IN1 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 RT CT, Toff = 0.69 RT CT. 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 oC the alarm output becomes low (TEA3718SP) When Tj reaches T2 oC the pre-alarm output becomes low (T2PULSE TIME VS(B) GND VSS IN1
PHASE
IN0
COMPARATOR INPUT
REFERENCE VS(A) OUTA SENSE RESISTOR ALARM PRE-ALARM
Table 3.
Device comparison table
Current 1.5 A 1.5 A 1.5 A 1.5 A Package Power DIP 12+2+2 SO20 Multiwatt 15 Power DIP 12+2+2 Connected Not connected Alarm Pre-alarm Not connected Connected
Device TEA3718SDP TEA3718SFP TEA3718SP TEA3718DP
6/26
Electrical specifications
3
3.1
Table 4.
Symbol VSS VS
Electrical specifications
Absolute maximum ratings
Absolute maximum ratings
Parameters Supply voltage Input voltage: - logic inputs - analog inputs - reference input Input current: - logic inputs - analog inputs Output current Junction temperature Operating ambient temperature range Storage temperature range Value 7 50 6 VSS 15 -10 -10 1.5 +150 0 to 70 V Unit
VI
V
ii IO TJ Top Tstg
mA A
oC oC
-55 to +150 oC
3.2
Table 5.
Symbol VSS Vs Im Tamb tr tf
Recommended operating conditions
Recommended operating conditions
Parameters Supply voltage Supply voltage Output current Ambient temperature Rise time for logic inputs Fall time for logic inputs SO20 4.75 10 0.020 0 Power DIP 5 Multiwatt 15 5.25 45 1.2 70 2 2 V V A
oC
Unit
s s
7/26
Electrical specifications
3.3
Table 6.
Symbol Rth(j-c) Rth(j-a)
Thermal data
Thermal data
Parameters Maximum junction-case thermal resistance Maximum junction-ambient thermal resistance
2
SO20 16 60(1)
Power DIP 11 45(1)
Multiwatt 15 3 40
o o
Unit C/W C/W
1. Soldered on a 35 m thick 4 cm PC board copper area
Figure 5.
Maximum power dissipation
Figure 6.
Typical external component configuration
RS = 1 ohm inductance free RC = 470 ohms CC = 820 pF ceramic Rt = 56 kohms Ct = 820 pF ceramic P = 500 ohms R2 = 1 kohm
8/26
Electrical specifications Figure 7. Output waveforms
9/26
Electrical specifications
3.4
Table 7.
Electrical characteristics
Electrical characteristics(1)
.
ICC VIH VIL IIH IIL VCH VCM VCL ICO Ioff Vsat(total) Ptot toff td Vsat(alarm) Iref
Supply current High level input voltage - logic inputs 2 Low level input voltage - logic inputs High level input current - logic inputs Low level input current - logic inputs (VI = 0.4 V) Comparator threshold voltage (VR = 5V) IO = 0, I1 = 0 IO = 0, I1 = 0 IO = 0, I1 = 0 Comparator input current Output leakage current (IO = 0, I1 = 1 Tamb = Total saturation voltage drop (Im = 1 A) SO20/Power DIP Multiwatt Total power dissipation - Im = 1 A, fs = 30 kHz Cut off time (see Figure 6 and Figure 7, Vmm = 10 V Vton > 5 s Turn off delay (see Figure 6 and Figure 7) Tamb = 25oC, dVC/dt > 50 mV/s) Alarm output saturation voltage IO = 2 mA (Multiwatt) Reference input current, VR = 5 V Power DIP Im = 0.5 A Power DIP Im = 1 A Multiwatt Im = 0.5 A Multiwatt Im = 1 A If(source) = 0.5 A If(source) = 1 A If = 1A Power DIP Im = 0.5 A Power DIP Im = 1 A Multiwatt Im = 0.5 A Multiwatt Im = 1 A If(sink) = 0.5 A If(sink) = 1 A 25oC)
2 -0.4 390 230 65 -20 25 -
420 250 80 3.1 30 1.6 0.8 0.4 1.05 1.35 1.1 1.25 1 1.2 1 1.1
25 0.8 20 440 270 90 20 100 2.8 3.2 3.6 35 1
mA V V A mA
mV A A
V W ms s V mA
Vsat(source)
Source diode transistor pair saturation voltage
1.2 (1.3) V 1.5 (1.7) 1.3 1.7 1.5 (1.6) V 1.7 (1.9) 5 mA V
Vf(source diode) Source diode forward voltage Isub Substrate leakage current
Vsat(sink)
Sink diode transistor pair saturation
1.2 (1.3) V 1.3 (1.5) 1.3 1.5 V
Vf(sink diode)
Sink diode forward voltage
1.4 (1.6) V 1.5 (1.9)
1. Vs = Vss = 5 V, 5%, Vmm = 10 V to 45V, Tamb = 0 to 70oC (Tamb = 25 oC for TEA3718SFP) unless otherwise specified. 2. Values in parentheses apply only to E-TEA3718SFP and E-TEA3718SFPTR mounted in SO20 package.
10/26
Electrical specifications Figure 8. Sink driver VCE sat against Iout and Tj
Figure 9.
Lower diode Vf against IOUT and Tj
Figure 10. Source driver VCE sat against IOUT and Tj
11/26
Electrical specifications Figure 11. Upper diode Vf against IOUT and Tj
Figure 12. Iref against junction temperature
Figure 13. Comparator input current against Tj and VC
12/26
Functional blocks
4
Functional blocks
Figure 14. Alarm output (TEA3718SP)
Figure 15. Pre-alarm output (TEA3718SFP)
13/26
Functional blocks
4.1
Alarm output (TEA3718SP, TEA3718DP and TEA3718SDP)
The ALARM output pin becomes low when the junction temperature reaches T C. When an alarm condition occurs, parts of the supply voltage (dividing bridge R - RC) is fed to the comparator input pin (Figure 16). Depending on the RC value the behavior of the circuit on an alarm condition is as follows:

RC > 80 ohms, the output stage is switched off RC > 60 ohms, the current in the motor windings is reduced according to the approximate formula: (see also Figure 18 and Figure 19)
VCC RC VTH Im = ---------- - ----------------- * ------RS R + RC RS
with VTH = threshold of the comparator (VCH, VCM, VCL) R = 700 ohms (typical). For several Multiwatt packages a common detection can be obtained as in Figure 17. Figure 16. Alarm detection for power DIP package
14/26
Functional blocks Figure 17. Common detection for several Multiwatt packages
4.2
Pre-alarm output (TEA3718SFP)
When the junction temperature reaches T1 C (typically = 170 C) a pre-alarm signal is generated on the PRE-ALARM output pin. Soft thermal protection occurs when function temperature reaches T2 (T2 > T1).
4.3
Note:
Current reduction in alarm condition
The resistance values given in this section are for the VCH threshold. They should be adjusted when using other comparator thresholds or Vref values.
Figure 18. Current reduction in the motor on alarm condition (typical curve)
15/26
Functional blocks Figure 19. Half-current on alarm condition circuit (Vref = 5 V)
4.4
Typical application
Figure 20. Typical application circuit
16/26
Functional description
5
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. There is a choice of three different current levels with the two logic inputs lN0 and lN1. The current can also be switched off completely.
5.1
Input logic
If any logic input is left open, the circuit treats it as a high-level input. Table 8.
l
Truth table
IN0 H L H L IN1 H H L L Current level No current Low current Medium current Maximum current
5.2
Phase input
The PHASE input pin determines the direction of current 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. A high level on the PHASE input causes the motor current flow from OUTA through the winding to OUTB. The lH0 and lH1 input pins select the current level in the motor winding. The values of the different current levels are determined by the reference voltage VR together with the value of the sensing resistor RS.
5.3
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 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 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.
17/26
Functional description
5.4
Single-pulse generator
The pulse generator is a monostable triggered on the positive going edge of the comparator output. The monostable output is high during the pulse time, toff, which is determined by the timing components RT and CT. toff = 0.69 RT 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 toff, it is ignored.
5.5
Output stage
The output stage contains four Darlington transistors and four diodes, connected in an Hbridge. The two sinking transistors are used to switch the power supplied to the motor winding, thus driving a constant current through the winding.
Note:
It is not permitted to short circuit the outputs.
5.6
VSS, VS and VR
The circuit stands any order of turn-on or turn-off the supply voltages VSS and VS. Normal dV/dt values are then assumed. Preferably, VR should track VSS during power on and power off if VS is established.
5.7
Analog control
The current levels can be varied continuously if VR is varied with a circuit varying the voltage on the comparator terminal. Figure 21. Power losses against output current
18/26
Application notes
6
6.1
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 excessively both 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.
6.2
Unused inputs
Unused inputs should be connected to proper voltage levels in order to get the highest noise immunity.
6.3
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 package between 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 Section 4: Functional blocks.
19/26
Application notes
6.4
Operating sequence
Figure 22. Principal operating sequence
20/26
Package mechanical data
7
Package mechanical data
In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK(R) packages, depending on their level of environmental compliance. ECOPACK(R) specifications, grade definitions and product status are available at: www.st.com. ECOPACK(R) is an ST trademark.
21/26
Package mechanical data
22/26
Package mechanical data
23/26
Package mechanical data
24/26
Revision history
Revision history
Table 9.
Date 24-Jan-2006 21-Jan-2009
Document revision history
Revision 1 2 Initial release. Document reformatted. Added Figure 1. Changes
25/26
Please Read Carefully:
Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries ("ST") reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST's terms and conditions of sale. Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no liability whatsoever relating to the choice, selection or use of the ST products and services described herein. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. If any part of this document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such third party products or services or any intellectual property contained therein.
UNLESS OTHERWISE SET FORTH IN ST'S TERMS AND CONDITIONS OF SALE ST DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY WITH RESPECT TO THE USE AND/OR SALE OF ST PRODUCTS INCLUDING WITHOUT LIMITATION IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION), OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZED ST REPRESENTATIVE, ST PRODUCTS ARE NOT RECOMMENDED, AUTHORIZED OR WARRANTED FOR USE IN MILITARY, AIR CRAFT, SPACE, LIFE SAVING, OR LIFE SUSTAINING APPLICATIONS, NOR IN PRODUCTS OR SYSTEMS WHERE FAILURE OR MALFUNCTION MAY RESULT IN PERSONAL INJURY, DEATH, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE. ST PRODUCTS WHICH ARE NOT SPECIFIED AS "AUTOMOTIVE GRADE" MAY ONLY BE USED IN AUTOMOTIVE APPLICATIONS AT USER'S OWN RISK.
Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any liability of ST.
ST and the ST logo are trademarks or registered trademarks of ST in various countries. Information in this document supersedes and replaces all information previously supplied. The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners.
(c) 2009 STMicroelectronics - All rights reserved STMicroelectronics group of companies Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America www.st.com
26/26

▲Up To Search▲

Price & Availability of TEA3718SFPTR

	To Download TEA3718SFPTR Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .