L6219R

L6219R STMICROELECTRONICS | Alldatasheet

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Technical content

Figure 3. Pin Connection (Top view) Table 2. Pin Description Note: ESD on GND, VS, VSS, OUT 1A and OUT 2A is guaranteed up to 1.5KV (Human Body Model, 1500W, 100pF).

Description

1;2 OUTPUT A See pins 5;21 3;23 SENSE RESISTOR Connection to Lower Emitters of Output Stage for Insertion of Current Sense Resistor 4;22 COMPARATOR INPUT Input connected to the comparators. The voltage across the sense resistor is feedback to this input throught the low pass filter RC CC. The higher power transistors 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 = 1.1 RT CT). See fig. 4. 5;21 OUTPUT B Output Connection. The output stage is a "H" bridge formed by four transistors and four diodes suitable for switching applications. 6;19 GROUND See pins 7;18 7;18 GROUND Ground Connection. With pins 6 and 19 also conducts heat from die to printed circuit copper. 8;20 INPUT 0 See INPUT 1 (pins 9;17) 9;17 INPUT 1 These pins and pins 8;20 (INPUT 0) are logic inputs which select the outputs of the comparators to set the current level. Current also depends on the sensing resistor and reference voltage. See Funcional Description. 10;16 PHASE This TTL-compatible logic inputs sets the direction of current flow through the load. A high level causes current to flow from OUTPUT A (source) to OUTPUT B (sink). A schmitt trigger on this input provides good noise immunity and a delay circuit prevents output stage short circuits during switching. 11;15 REFERENCE VOLTAGE A voltage applied to this pin sets the reference voltage of the comparators, this determining the output current (also thus depending on Rs and the two inputs INPUT 0 and INPUT 1). 12;14 RC A parallel RC network connected to this pin sets the OFF time of the higher power transistors. The pulse generator is a monostable triggered by the output of the comparators (toff = 1.1 RT CT). Vss - LOGIC SUPPLY Supply Voltage Input for Logic Circuitry Vs - LOAD SUPPLY Supply Voltage Input for the Output Stages.

Table 3. Absolute Maximum Ratings Table 4. Thermal Data (*) With minimized copper area. Thermal Resistance Junction-case Max. Thermal Resistance Junction-ambient Max. 75 (*) °C/W °C/W Table 5. Electrical Characteristics

*) ICEX is the sum of the leakage of the power switch and recirculation diode. Table 5. Electrical Characteristics (continued)

The circuit is intended to drive both windings of a bipolar stepper motor. The peak current control is generated through switch mode regulation.There is a choice of three different current levels with the two logic inputs I01 - I11 for winding 1 and I02 - I12 for winding 2. The current can also be switched off completely

3.1 Input Logic (I0 and I1)

The current level in the motor winding is selected with these inputs. (See fig. 5) If any of the logic inputs is left open, the circuit will treat it has a high level input. Table 6.

3.2 Phase

This input determines the direction of current flow in the windings, 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 Out A through the winding to Out B

3.3 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 Io and I1.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 goes high, which triggers the pulse generator. The max peak current Imax can be defined by: See figures 4, 5 and 6 for maximum allowable output current and reference voltage versus Vs supply.

3.4 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 time components Rt and Ct. toff = 1.1 · RtCt The single pulse switches off the power feed to the motor winding, causing the winding current to decrease dur- ing toff.If a new trigger signal should occur during toff, it is ignored.

3.5 Output Stage

The output stage contains four Darlington transistors (source drivers) four saturated transistors (sink drivers) and eight diodes, connected in two H bridge. Current Level H H No Current L H Low current 1/3 IO max H L Medium current 2/3 IO max L L Maximum current IO max Imax Vref 10Rs

Figure 5. Principle Operating Sequence rent through the winding.It should be noted however, that is not permitted to short circuit the outputs.

3.6 VS, VSS, VRef

Preferably, VRef should be tracking VSS during power-on and power-off if VS is established.

Unused inputs should be connected to proper voltage levels in order to get the highest noise immunity. the package between power line and ground. The ground lead between Rs, and circuit GND should be kept as short as possible. A typical Application Circuit is shown in Fig. 6. Note that Ct must be NPO type or similar else. Figure 6. Typical Application Circuit.

Package Information

Figure 10. SO24 Mechanical Data & Package

Revision History

Table 7. Revision History

Information furnished is believed to be accurate and reliable. However, STMicroelectronics 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 STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners © 2005 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 L6219R