5P35021_17 Datasheet, PDF (8/34 Pages) Integrated Device Technology – Programmable Clock Generator

5P35021 DATASHEET
OE Pin Function Summary (Note: OE2, OE3 and SE2, SE3 pins are only available in 5P35023)
OE1: SE1
* OE2: SE2
* OE2: SE3
* OE2: DIFF1/DIFF2
OE1: PD#
OE1: SE1_PPS
* OE1: SE2_PPS
* OE1: SE3_PPS
OE1:DFC0
* OE3/DFC1
OE1 only control SE1 enable/disable, other outputs are not affected by this pin status
OE2 only control SE2 enable/disable, other outputs are not affected by this pin status
OE3 only control SE3 enable/disable, other outputs are not affected by this pin status
OE2 control Differential outputs 1 and 2 only, other SE outputs are not affected by this pin status
OE1 control chip global power down (PD#) except 32.768KHz on OE1 (when 32K is enabled),
Config OE1 as SE1_PPS (Proactive Power Saving) funciton pin
Config OE2 as SE2_PPS (Proactive Power Saving) function pin
Config OE3 as SE3_PPS (Proactive Power Saving) function pin
Config OE1 as DFC0 control pin0
Config OE3 as DFC1 control pin1
PD# Priority Table
PD#
0
1
1
1
I2C_OE_EN_bit
x
0
1
1
SE1, DIFF1/DIFF2
SE1_PPS
x
x
0
1
Output
stop
stop
stop
running
Notes
32KHz free run
Reference Input and Selection
The 5P35021 accepts crystal input or LVCMOS/Differential clocks input by external AC coupling. See below reference circuit for
details
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, 5P35021 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.
VERSACLOCK^® PROGRAMMABLE CLOCK GENERATOR
8
JANUARY 25, 2017