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Functional Modes
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SLCU002 – September 2016
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Copyright © 2016, Texas Instruments Incorporated
BOOSTXL-ULN2003 Dual Stepper Motor Driver BoosterPack Hardware
4
Functional Modes
4.1
Modes of Operation Overview
Figure 23
provides a brief overview of how the Boosterpack pins are connected to either the SN74HC595
or the ULN2003A based on the selected mode of operation. Additional details for 3-pin mode and 8-pin
mode can be found in
Section 4.2
and
Section 4.3
respectively.
(1)
*There are NO resistors populated for pins GP6, GP2, GP9, and GP10, therefore there will be no direct
connection to IN5, IN6, IN7, and IN8 respectively. 0 Ohm or solder bridge connections can be made to
connect these pins in order to enable the full functionality of 8 pin mode. See
Section 4.3.1
for additional
details
(2)
~There IS a resistor populated for pin IN4, therefore it can be used in 8-pin mode without bus contention;
however, in 3-pin mode it will draw current if GP8 is set low. The resistor allows IN4 and GP8 to be different
voltage levels when GP8 is being used for another purpose while the Boosterpack is in 3-pin mode. See
Section 4.2.1
for additional details.
Figure 23. BOOSTXL-ULN2003 Mode Overview