AN1978 - APPLICATION NOTE

7/14

Figure 8: Vcc loaded with a 65mA pulsed current.

Figure 9: Step-up and Vcc capacitors placement.

CH1: Vcc voltage; offset=5V;

BandWidth=250MHz.

CH4: Vcc output current into

GND.

Conditions:

VDD=3.3V;

VDDP=4.75V;

5/3V=H.

The Vcc voltage is between

4.6V and 5.3V even if a 65mA

sink pulsed current is forced.

V

VUP wire

PGND

S2

S1

V

DDP

V

UP

Card

connector

Vcc

C1 (Vcc)

Vcc

C1 (Vcc)

C2 (RST)

C3 (CLK)

C4 (AUX1)

C5(GND)

C6 (N.C.)

C7 (I/O)

C8 (AUX2)

Card

connector

C11:

100nF filter

capacitor

PRES and PRES

V

VUP wire

PGND

S2

S1

V

DDP

V

UP

Card

connector

Vcc

C1 (Vcc)

Vcc

C1 (Vcc)

C2 (RST)

C3 (CLK)

C4 (AUX1)

C5(GND)

C6 (N.C.)

C7 (I/O)

C8 (AUX2)

Card

connector

C11:

100nF filter

capacitor

PRES and PRES

V

VUP wire

PGND

S2

S1

V

DDP

V

UP

Card

connector

Vcc

C1 (Vcc)

Vcc

C1 (Vcc)

C2 (RST)

C3 (CLK)

C4 (AUX1)

C5(GND)

C6 (N.C.)

C7 (I/O)

C8 (AUX2)

Card

connector

C11:

100nF filter

capacitor

PRES and PRES