Download AT91 ARM Thumb-based Microcontrollers Application Note

Application Note
3. Schematic Check List
1.8V and 3.3V Dual Power Supply with 3.3V Powered Memories Schematic Example
100nF
VDDANA
GNDANA
100nF
VDDIOP1
GND
VDDIOP0
10µF
DC/DC Converter
100nF
GND
VDDIOM
3.3V
10µF
100nF
GND
100nF
VDDPLL
GNDPLL
100nF
VDDBU
DC/DC Converter
GNDBU
VDDCORE
1.8V
10µF
100nF
GND
1.8V and 3.3V Dual Power Supply Schematic Example:(1)
3.3V external memories (VDDIOM) - 3.3V Image Sensor (VDDIOP1) - ADC (VDDANA) is used
;
Signal Name
Recommended Pin Connection
Description
VDDCORE
1.65V to 1.95V
Decoupling/Filtering capacitors
(100 nF and 10µF)(1)(2)
VDDPLL
1.65V to 1.95V
Decoupling capacitor (100 nF)(1)(2)
Powers the PLL cells and the Main Oscillator.
VDDBU
1.65V to 1.95V
Decoupling capacitor (100 nF)(1)(2)
Powers the Backup I/O lines
(Slow Clock Oscillator and a part of the System
Controller).
Powers the device.
Decoupling/Filtering capacitors must be added to improve
startup stability and reduce source voltage drop.
3
6275E–ATARM–18-Dec-07