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May 2010 Doc ID 16599 Rev 2 1/34

AN3097

Application note

EVAL6460 demonstration board based on

the L6460 SPI configurable stepper and DC multi motor driver

Introduction

The L6460 is optimized to control and drive multi-motor systems, providing a unique level of

integration in terms of control, power, and auxiliary features. Thanks to its high

configurability the L6460 can be customized to drive different motor architectures and to

optimize the number of embedded features, such as the voltage regulators, the high

precision A-D converter, the operational amplifier and the voltage comparators. The

possibility of simultaneously driving the stepper and DC motors makes the L6460 the ideal

solution for all applications featuring multi motors.

The L6460 can communicate with an external microprocessor by using an integrated slave

SPI (serial protocol interface); through this interface the majority of the L6460’s functions

can be controlled.

Master device interfacing with multiple SPI slave devices has an nSS signal to address each

slave device.

Figure 1. EVAL6460 demonstration board

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Summary of content (34 pages)

PAGE 1
AN3097 Application note EVAL6460 demonstration board based on the L6460 SPI configurable stepper and DC multi motor driver Introduction The L6460 is optimized to control and drive multi-motor systems, providing a unique level of integration in terms of control, power, and auxiliary features.
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Contents AN3097 Contents 1 The L6460 main features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2 EVAL6460 board description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3 The EVAL6460 controlled by the EVAL_IBU-STR7 . . . . . . . . . . . . . . . . 11 3.1 3.2 4 2/34 Board connection and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.1.1 Jumper configuration . . . . . . . . . . . . . . . . . . . . . . . . . . .
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AN3097 List of figures List of figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. Figure 22. Figure 23. Figure 24. Figure 25. Figure 26. Figure 27. Figure 28. Figure 29. Figure 30. Figure 31. Figure 32. Figure 33. Figure 34. Figure 35. Figure 36. EVAL6460 demonstration board. . . . . . . . . . . . . . . . . . . . . . . . . . . .
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The L6460 main features 1 AN3097 The L6460 main features Four widely configurable full bridges: ● ● Bridges 1 and 2: – Diagonal Ron: 0.6 Ω typ. – Max. operative current = 2.5 A Bridges 3 and 4: – Diagonal Ron: 0.85 Ω typ. – Max. operative current = 1.5 A Possible configurations for each bridge: ● Bridge 1: – DC motor driver – Super DC (bridge 1and 2 parallel to form super-bridge 1).
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AN3097 The L6460 main features ● ● One buck type switching regulator (VswMain) with: – Output regulated voltage range: 1-5 V – Max output load current: 3.
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EVAL6460 board description 2 AN3097 EVAL6460 board description This demonstration board shows an example of an application which the L6460 is able to manage: ● 2 DC motors ● 1 stepper motor ● 3 power supplies: 1.2 V, 3.3 V and 12 V. Table 1 summarizes the operating rating specification of the application, Table 2 lists the connectors and jumpers available on the board and their function; Figure 2 shows the electrical schematic and Table 3 shows the BOM list. Table 1.
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AN3097 EVAL6460 board description Table 2.
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AN3097 Table 3.
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EVAL6460 board description AN3097 Figure 3 and 4 show the component placement and the four-layer layout of the EVAL6460 demonstration board. Figure 3. EVAL6460 component placement (top and bottom) "OTTOM 4OP !- V Figure 4.
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AN3097 3 The EVAL6460 controlled by the EVAL_IBU-STR7 The EVAL6460 controlled by the EVAL_IBU-STR7 The EVAL_IBU-STR7 is a control interface board dedicated to the EVAL6460 control; it communicates with the PC and the flexSPIN evaluation software via a serial port (RS232). The EVAL6460 is connected to the STR7 interface board via a standard 34-pin ribbon cable interface.
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AN3097 3.1 The EVAL6460 controlled by the EVAL_IBU-STR7 Board connection and configuration In this section the configuration of the EVAL6460 board, how to connect the board supply, loads, and interface it to a PC through the EVAL_IBU-STR7 is shown. 3.1.1 Jumper configuration 1. Startup configuration (refer to the L6460 datasheet - startup configurations section). Figure 7. Jumper startup configuration All the jumpers are kept low: the single-device major mode is set. 2. Device ID Figure 8.
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The EVAL6460 controlled by the EVAL_IBU-STR7 3. AN3097 nAwake driving source (refer to the L6460 section - nAWAKE pin) Figure 9. nAwake driving source Here in the "master" position, place it in the alternative position on the board used as slave. 4. Awake input (refer to the L6460 section - nAWAKE pin) Figure 10. Awake input This jumper must be closed on the master board, in this way the nAWAKE pin can be driven by the EVAL_IBU-STR7 board. 5. Stepper current sense resistor value Figure 11.
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AN3097 The EVAL6460 controlled by the EVAL_IBU-STR7 6. nRESET feedback capability Figure 12. nRESET feedback capability By closing this jumper the nRESET pin is directly readable by the EVAL_IBU-STR7. 3.1.2 3.1.3 Loads and board supply connection 1. Connect the DC motor to the DC1 (J3) and DC2 (J4) connectors 2. Connect the stepper motor to the DC3 (J5) and DC4 (J6) connectors 3. Connect the regulator loads: a) 5.1 Ω - 50 W to VSWDRV (J9) connector b) 1.
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The EVAL6460 controlled by the EVAL_IBU-STR7 AN3097 Figure 13. FlexSPIN evaluation software - start window Moving the mouse cursor over the image, a brief description of highlighted areas appears on the bottom line. Clicking on some areas, a window appears with the related electrical schematic. 3.2.1 How to turn-on the VswDrv regulator The integrated switching regulator controller is able to drive an external FET to implement a switching buck regulator.
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AN3097 The EVAL6460 controlled by the EVAL_IBU-STR7 Click the "Switching Reg. controller" button, the "Switching Regulator controller" window then appears (Figure 15). Figure 15. Switching regulator controller To obtain the output voltage of 12 V as prearranged (VSupply = 24 V), do the following (see Figure 16): 1. Raise the duty cycle of the generated pulse to 58% by clicking the "+" button close to the value 2. Tick the "Enable" auto-check box, the VswDrv then turns-on. Figure 16.
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The EVAL6460 controlled by the EVAL_IBU-STR7 AN3097 Figure 17. Current DAC block diagram Here you can set the LSB typical current and the relative full scale typical current, then by writing the DAC value in the text box you can set the amount of current sink by the feedback pin of the switching regulator. In this way, after the enabling of the current sink DAC you can obtain an output voltage higher than the previous one on the VswDrv connector (J9). 3.2.
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AN3097 The EVAL6460 controlled by the EVAL_IBU-STR7 By ticking the auto-check boxes, you can configure the operation mode of the single half bridge outputs.
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The EVAL6460 controlled by the EVAL_IBU-STR7 AN3097 Figure 20. Bridge 3 and 4 configuration In this window you can set the use of bridges 3 and 4: the default configuration allows the choosing of the output driving as mentioned for bridge 1 and 2. Clicking on one of the "Set configuration and enable" buttons and then on the "PWM3 - PWM4" button, the following window appears (Figure 21). Figure 21.
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AN3097 The EVAL6460 controlled by the EVAL_IBU-STR7 By ticking the auto-check boxes, you can configure the operation mode of the single half bridge outputs.
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The EVAL6460 controlled by the EVAL_IBU-STR7 AN3097 In this window select "Config" under the "Stepper controller" rectangle, the "Bipolar Stepper Configuration" appears. In this window it is possible to set some parameters: ● Decay mode ● Offtime ● Blanking time ● Voltage reference for the current control ● Direction ● Driving mode ● Clock source Configure the stepper controller as shown in Figure 23. Figure 23.
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AN3097 The EVAL6460 controlled by the EVAL_IBU-STR7 Figure 24. GPIO12 and GPIO13 configuration 3.2.4 How to assign and read a GPIO Some of the pins of the L6460 are indicated as GPIO (general purpose I/O). These pins can be configured to be used in different ways depending on customer application. All GPIOs can be used as digital input/output pins with digital value settable/readable using serial interface or as analog input pins that can be converted using the A2D system.
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The EVAL6460 controlled by the EVAL_IBU-STR7 AN3097 Figure 25. GPIOs block diagram On the top part there are the logic values read from each GPIO. To read again push the "refresh" button. By pushing the "Adc" button you can read the voltage value of each GPIO and convert it using the internal A-to-D converter. For example, (refer to Figure 26) click the switch close to GPIO4 closing it, then in the column of GPIO4 click the button at the bottom (it has the logic level written inside).
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AN3097 3.2.5 The EVAL6460 controlled by the EVAL_IBU-STR7 How to read and clear an undervoltage event The L6460 integrates an nRESET circuit that monitors VSupply, VSupply_int, VPump, VGPIO_SPI and all system regulator voltages (VSystem). The purpose of this circuit is to prevent the device functioning until the monitored voltages reach their operative value and do not fall below their own undervoltage threshold.
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The EVAL6460 controlled by the EVAL_IBU-STR7 AN3097 Figure 28. Interrupt controller diagram Here you can choose the events that can cause an interrupt signal. 3.2.7 How to put the device into "low power" condition and awaken it When in normal operating mode, the microcontroller can place the L6460 in "low power mode".
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AN3097 The EVAL6460 controlled by the EVAL_IBU-STR7 Figure 29. GPIO11 configuration for PWM !- V 3.2.9 How to close the low voltage power switch Low voltage power switches are analog switches designed to operate from a single +2.4 V to +3.6 V VGPIO_SPI supply. They are intended to provide and remove the power supply to low voltage devices.
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The EVAL6460 controlled by the EVAL_IBU-STR7 AN3097 Figure 31. Low power switch 1 disable 3.2.10 How to measure an input voltage using A-D converter The L6460 integrates and makes a general purpose multi-input channel 3.3 V analog to digital converter (ADC) accessible via the SPI. In the first software window click the L6460 device and then the ADC button, the A-D window appears (Figure 32). Figure 32. A-D block diagram The A-D has two channels, each with 32 selectable inputs.
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AN3097 The EVAL6460 controlled by the EVAL_IBU-STR7 To start the conversion push the "Start0" or "Start1" buttons, in the text box you can read the result register and the related voltage (the most significant bit of the result register is the "done" flag). 3.2.
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The EVAL6460 controlled by the EVAL_IBU-STR7 AN3097 Figure 35. FlexSPIN sequencer window With this tool you can configure all device registers and program some command sequences to drive the L6460. ● 30/34 Button description: – Browse: to set the file location to load – Save as: to save a sequence. The default format for the sequences is "txt". The sequence is saved in ASCII format and it can be modified with a text editor – START: run the sequence.
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AN3097 The EVAL6460 controlled by the EVAL_IBU-STR7 ● Note: To choose a statement use the + or - buttons near the "Statement" field. The instruction set is: – Add/sub/mul/div: add/subtract/multiply/divide a variable and a constant, the result is put into the variable register – Inc/dec: increment/decrement a variable of 1 unit – Logicaland/or/exor: make the and/or/exor logical operation between a variable and a constant.
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The EVAL6460 controlled by the EVAL_IBU-STR7 AN3097 Figure 36. Thermal manager window 3.2.14 How to work in master - slave configuration 1. Note: 32/34 Configure the slave board as described: – JP1 in slave position – Configuration jumpers: JP2 high, JP3 open, JP4 low – Set the ID jumper: JP5 high and JP6 low – Awake input: JP9 open 2. Connect the slave board to the master board using the 10 pin connectors (J1) 3. Connect loads and supplies 4.
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AN3097 4 Revision history Revision history Table 4.
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AN3097 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.