User Manual Part 1

CY8CKIT-042-BLE Bluetooth® Low Energy (BLE) Pioneer Kit Guide, Doc. # 001-93731 Rev. *A 91
Hardware
■ A MOSFET-based protection circuit is provided for overvoltage and reverse-voltage protection for
the 3.3-V rail from J1.5, as shown in Figure 5-4. When a voltage greater than 3.6 V is applied
from J1.5, the Q2 PMOS will turn off, which will cut off the power to the BLE module from J1.5.
When reverse voltage is applied from J1.5, the Q1 PMOS will turn off, protecting the onboard
components from reverse voltage.
Figure 5-4. Schematics and Board Highlight of MOSFET Protection Circuit for 3.3-V Input
VDDV3.3
NO LOAD
R9
10K
R8
15K
Q2
PMOS( NTR4171PT1G)
R7 ZERO
D9
Vz=3.9V(BZT52C3V9-7-F)
Q3
PMOS(PMV48XP,215)
Q1
PMOS( DMP3098L-7)