Texas Instruments BOOSTXL-ULN2003, Руководство пользователя

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GP11 GP12 GP13
SRCLK
IN3
RCLK
IN2
SER
IN1
OE
DGND
3V3
3
1
2
6
4
5
S2
3
1
2
6
4
5
S1
560
R11
560
R12
560
R13
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Hardware Description
9 SLCU002 – September 2016
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Copyright © 2016, Texas Instruments Incorporated
BOOSTXL-ULN2003 Dual Stepper Motor Driver BoosterPack Hardware
2.4.2 Switches
The four on-board dip switches are used to select between 3-pin mode and 8-pin mode operation of the
BoosterPack. Descriptions for each of the switches are provided in
Table 2 .
Figure 7. Board Image of Switches
Figure 8. Schematic View of Switches
Table 2. Dip Switch Description
Reference Description
S1 - GP11
This SPDT switch directs the signal from BoosterPack header input GP11. If the switch
is down, it connects GP11 to the SER input of the SN74HC595. If the switch is up, it
connects GP11 directly to IN1 – ultimately connected to the gate of the CSD17571Q2
FET.
Switch Down = 3-pin Serial Mode
Switch Up = 8-pin Parallel Mode
S1 - GP12
This SPDT switch directs the signal from BoosterPack header input GP12. If the switch
is down, it connects GP12 to the RCLK input of the SN74HC595. If the switch is up, it
connects GP12 directly to IN2 – ultimately connected to 1B of the ULN2003A device.
Switch Down = 3-pin Serial Mode
Switch Up = 8-pin Parallel Mode
S2 - GP13
This SPDT switch directs the signal from BoosterPack header input GP13. If the switch
is down, it connects GP13 to the SRCLK input of the SN74HC595. If the switch is up, it
connects GP13 directly to IN3 – ultimately connected to the 2B of the ULN2003A
device.
Switch Down = 3-pin Serial Mode
Switch Up = 8-pin Parallel Mode
S2 - HC595
This SPDT switch connects the OE pin either to 3V3 or DGND. This determines
whether or not the SN74HC595 outputs are enabled or are in high-impedance (Hi-Z)
mode. If the switch is down, it enables the SN74HC595 outputs. If the switch is up, it
disables the SN74HC595 outputs. Disabling these outputs is required for 8-pin Parallel
Mode to avoid bus contention at the inputs of the ULN2003A and the CSD17571Q2
FET.
Switch Down = 3-pin Serial Mode
Switch Up = 8-pin Parallel Mode