•
the CPU fequency must be higher 8MHz when USB is active (No contrain for USB suspend mode)
•
the operating voltages must be 3.3V (Min. 3.0V, Max. 3.6V).
•
the GCLK_USB frequency accuracy source must be less than:
–
in USB device mode, 48MHz +/-0.25%
Table 45-49. GCLK_USB Clock Setup Recommendations
Clock setup
USB Device
DFLL48M
Open loop
No
Close loop, Ref. internal OSC source
No
Close loop, Ref. external XOSC source
Yes
Close loop, Ref. SOF (USB recovery mode)
(1)
Yes
(2)
FDPLL
internal OSC (32K, 8M…)
No
external OSC (<1MHz)
Yes
external OSC (>1MHz)
Yes
(3)
Note:
1.
When using DFLL48M in USB recovery mode, the Fine Step value must be Ah to guarantee a USB
clock at +/-0.25% before 11ms after a resume. Only usable in LDO regulator mode.
2.
Very high signal quality and crystal less. It is the best setup for USB Device mode.
3.
FDPLL lock time is short when the clock frequency source is high (> 1 MHz). Thus, FDPLL and
external OSC can be stopped during USB suspend mode to reduce consumption and guarantee a
USB wakeup time (See TDRSMDN in USB specification).
45.14. SLCD Characteristics
The values in the table below are measured values of power consumption under the following conditions,
except where noted:
•
T=25°C. Standby Mode. Low Power waveform Mode. Frame Rate = 32Hz from ULP32K Oscillator.
•
No ACM, ABM or Segment Animation Features activated
•
All Segments on, No Glass Load = 0pF and With Glass Load = 22pF on each COM and SEG line.
•
Contrast Adjustment CTST control set to 0x7 (~2.97V) when using internal VLCD generation
•
No Bias Buffer. No External Bias Output. No Low Resistance Network Enable
•
Reference Refresh Frequency = 500Hz. Power Refresh Frequency = 1kHz
•
I
LCD
current based on I
LCD
= I
stdby(LCD On)
- I
stdby (LCD Off)
. with I
stdby
= I
VDD
+ I
VDDANA
•
To minimize power consumption of the SLCD module use V
LCD
= V
DD
or V
LCD
> V
DD
+ 0.4V
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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