User manual

CY3280-MBR3 Evaluation Kit User Guide, Doc. #: 001-89905 Rev. *B 40
Hardware
2. Remove the USB cable connected to the kit.
3. Desolder (unpopulate) resistors R84 and R85 (Figure 4-6), which were previously loaded for
externally regulated mode operation.
4. Connect the USB cable to the kit and apply the EZ-Click configuration with the Supply Voltage (V)
parameter as 1.8-5.5, as shown in Figure 4-8.
Note: To operate the kit in internally regulated mode, the Supply Voltage (V) parameter should
be selected as 1.8-5.5, as shown in Figure 4-8.
4.3.3.2 Protection Circuit
The power supply rail has reverse-voltage, overvoltage, and short-circuit protection features.
■ The PTC resettable fuse is connected to protect the computer's USB ports from overcurrent; see
Figure 4-9.
Figure 4-9. USB Power Supply Section Schematic Snippet
■ D2 – A series protection diode to ensure there is no back power to the header; see Figure 4-3.
■ U4 – A PolyZen protection device (ZEN056V075A48LS) that protects the kit against overvoltage
and reverse voltage from the headers; see Figure 4-4.
Caution: There is no protection on the current measurement jumper, test points, and I/O pins. Do
not apply more than 5.5 V on these ports.
4.3.3.3 Procedure to Measure the CY8CMBR3116 Current Consumption
This kit provides a way to measure the current consumption of both the whole kit and the
CY8CMBR3116 device individually, without soldering. There are two separate jumpers on the board
for this purpose.