5L35021 Ver la hoja de datos (PDF) - Integrated Device Technology
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5L35021 Datasheet PDF : 37 Pages
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5L35021 Datasheet
Table 22. OE Pin Function Summary
OE Pin
OE1: SE1
OE1: PD#
OE1: SE1_PPS
OE1: DFC0
Description
OE1 only control SE1 enable/disable; other outputs are not affected by this pin status.
OE1 control chip global power down (PD#) except 32.768kHz on OE1 (when 32kHz is enabled). When the
PD# pin is active low, the chip goes to lowest power down mode and all outputs are disabled except 32kHz
output and only keep 32k/Xtal calibration.
Configure OE1 as SE1_PPS (Proactive Power Saving) function pin.
Configure OE1 as DFC0 control pin 0.
Table 23. PD# Priority
PD#
I2C_OE_EN_bit
0
x
1
0
1
1
1
1
SE1/2/3, DIFF1/DIFF2
x
x
0
1
Output
Stop
Stop
Stop
Running
Notes
32kHz free run
Crystal Input (X1/X2)
The crystal oscillators should be fundamental mode quartz crystals; overtone crystals are not suitable. Crystal frequency should be
specified for parallel resonance with 40MHz maximum.
A crystal manufacturer will calibrate its crystals to the nominal frequency with a certain load capacitance value. When the oscillator load
capacitance matches the crystal load capacitance, the oscillation frequency will be accurate as 0 PPM. When the oscillator load
capacitance is lower than the crystal load capacitance, the oscillation frequency will be higher than nominal. In order to get an accurate
oscillation frequency, the matching the oscillator load capacitance with the crystal load capacitance is required.
To set the oscillator load capacitance, 5L35021 has built-in two programmable tuning capacitors inside the chip, one at XIN and one at
XOUT. They can be adjusted independently. The value of each capacitor is composed of a fixed capacitance amount plus a variable
capacitance amount set with the XTAL[7:0] register. Adjustment of the crystal tuning capacitors allows for maximum flexibility to
accommodate crystals from various manufacturers. The range of tuning capacitor values available are in accordance with the following
table.
Table 24. Programmable Tuning Caps
Parameter
Bits
Xtal [7:0]
4×2
Range
+1 / +2 / +4 / +8pF
Minimum (pF)
0
Maximum (pF)
15pF
©2017 Integrated Device Technology, Inc.
16
July 13, 2017
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