PSoC
®
Thermal Management Expansion Board Kit Guide, Doc. No. 001-89649 Rev. **
12
2.2 Four-Wire Fans
The CY8CKIT-036 EBK has two four-wire fans onboard. The fans are from the vendor AVC, and the part number is
DB04028B12UP090. These DC brushless axial flow fans can spin at speeds of up to 13,000 rpm via PWM-based speed
control. These fans also have a tachometer output to calculate the fan speeds. For specifications, see the
manufacturer’s
fan datasheet on the
kit webpage
.
The CY8CKIT-036 EBK has a provision for interfacing up to four four-wire fans. Two sets of industry-standard connector
slots are available for each fan: One is the four-pin header with a 2.54-mm pitch, and the other is a four-pin header with a
1.25-mm pitch. The four 2.54-mm headers are labeled J7, J8, J10, J11 respectively. The four 1.25-mm headers are labeled
J4, J5, J6, J12 respectively. The two fans provided along with the EBK are connected to the J7 and J8 headers by default.
They can be connected to any of the 2.54-mm headers, depending on the requirements. You can connect two additional
fans to the remaining two connection headers.
Table 2-1
shows the pin assignment of the four-pin fan headers (both 2.54 mm and 1.25 mm) and the color coding of the
wires used for connecting the two fans on the kit to these headers.
Table 2-1. Fan Connector Pinouts
Pin Number
Name
Colors
Description
1
GND
Black
GND
2
POWER
Red
12 V DC power
3
TACH
Yellow
Frequency generator signal
4
PWM
Blue
PWM control signal
The fans require a 12-V power supply and usually take about 0.5 A of input current. The CY8CKIT-036 EBK includes a
12-V DC high-current power supply that is capable of providing the inrush current needed by the fans installed on the kit.
Connect the high-current power supply to the power connector (J13), and set the power jumper (J9) on the CY8CKIT-036
EBK board to 12V_EXT (the default setting).
Figure 2-2. 12 V Power Supply Selection (Jumper J9)
The tachometer signals from the fans have an onboard external pull-up resistor (4.7 K) to VDDIO for interfacing with PSoC.
The value of the VDDIO power supply is controlled by jumper J3 (3.3 V or 5 V). The VDDIO selection (see
Figure 2-3
)
should be the same as the VDD operating voltage of the PSoC chip.
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