Atmel SAM4L Xplained Pro Starter Kit Atmel ATSAM4L-XSTK ATSAM4L-XSTK Data Sheet

42023E–SAM–07/2013

The internal regulator is connected to the VDDIN pin and its output VDDOUT feeds VDDCORE
in linear mode or through an inductor in switching mode. 

 shows the power schematics

to be used. All I/O lines will be powered by the same power (V

VDDIN

=V

VDDIO

=V

VDDANA

).

Single Supply Mode

LCD lines is powered using the device internal voltage sources provided by the LCDPWR block.
When enabled, the LCDPWR blocks will generate the VLCD, BIASL, BIASH voltages. 

LCD pads are splitted into three clusters that can be powered independently namely clusters A,
B and C. A cluster can either be in GPIO mode or in LCD mode. 

When a cluster is in GPIO mode, its VDDIO pin must be powered externally. None of its GPIO
pin can be used as a LCD line

When a cluster is in LCD mode, each clusters VDDIO pin can be either forced externally (1.8-
3.6V) or unconnected (nc). GPIOs in a cluster are not available when it is in LCD mode. A clus-
ter is set in LCD mode by the LCDCA controller when it is enabled depending on the number of
segments configured. The LCDPWR block is powered by the VLCDIN pin inside cluster A

When LCD feature is not used, VLCDIN must be always powered (1.8-3.6V). VLCD, CAPH,
CAPL, BIASH, BIASL can be left unconnected in this case

VDDIN

VDDIO

VDDANA

VDDCORE

REGULATOR

ADC, DAC, AC0/1, 
RC32K,  OSC32K, 
BOD18, BOD33

RC80M, OSC, 

Core domain: CPU, 
Peripherals, RAM, Flash, 
RCSYS, PLL, DFLL, 
RCFAST

Backup domain: 
AST, WDT, EIC, 
BPM, BSCIF

Main Supply 

(1.68V-3.6V)

VDDOUT

BUCK/LDOn

(PA02)

VLCDIN

LCD VPUMP