R-IN32M4-CL3 User's Manual: Board design edition
4. PLL Power Supply Pins
R18UZ0074EJ0100
Page 10 of 61
Dec 24, 2019
4.
PLL Power Supply Pins
The PLL circuit is susceptible to noise. To reduce the influence of noise, it is recommended to place filters in the power
supply pins of the PLL. In addition, to reduce the effects of noise between the power supplies for the board and PLL, the
use of ferrite beads is recommended.
4.1
Recommended Configuration of Filter
Figure 4.1 shows the recommended configuration of the filter for the PLL power supply pins.
C1
PLL
PLL_GND
PLL_VDD
R-IN32M4-CL3
VDD11 (1.15 V)
C2
C1: 0.1-µF ceramic capacitor
C2:
³
4.7-µF capacitor
FB
FB
FB: Impedance: 600
Ω at 100 MHz / DC resistance component: 0.3 Ω or below
Reference ferrite beads: TDK MPZ2012S601A, MPZ1608S601A
Figure 4.1 Recommended Configuration of Filter
Caution:
Place C1 immediately close to R-IN32M4-CL3.
If C2 is not placed immediately close to R-IN32M4-CL3, this will not cause any problems.