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ICS840004I-01 Datasheet, PDF (2/16 Pages) Integrated Circuit Systems – FEMTOCLOCKS™ CRYSTAL-TO LVCMOS/LVTTL FREQUENCY SYNTHESIZER
ICS840004I-01
FEMTOCLOCKS™ CRYSTAL-TO-
LVCMOS/LVTTL FREQUENCY SYNTHESIZER
TABLE 1. PIN DESCRIPTIONS
Number
Name
Type
Description
1, 20
F_SEL0,
F_SEL1
Input Pullup Frequency select pin. LVCMOS/LVTTL interface levels.
2, 9
nc
Unused
No connect.
Selects between the crystal or REF_CLK inputs as the PLL reference
3
nXTAL_SEL Input Pulldown source. When HIGH, selects REF_CLK. When LOW, selects XTAL
inputs. LVCMOS/LVTTL interface levels.
4
REF_CLK
Input Pulldown Single-ended LVCMOS/LVTTL reference clock input.
5
OE
Input
Pullup
Output enable pin. When HIGH, the outputs are active. When LOW, the
outputs are in a high impedance state. LVCMOS/LVTTL interface levels.
Active HIGH Master Reset. When logic HIGH, the internal dividers are
6
MR
Input Pulldown reset causing the otuputs to go low. When logic LOW, the internal
dividers and the outputs are enabled. LVCMOS/LVTTL interface levels.
PLL Bypass. When LOW, the output is driven from the VCO output.
7
nPLL_SEL
Input
Pulldown
When HIGH, the PLL is bypassed and the output frequency =
reference clock frequency/N output divider.
LVCMOS/LVTTL interface levels.
8
V
Power
DDA
10
VDD
Power
11,
12
XTAL_OUT,
XTAL_IN
Input
Analog supply pin.
Core supply pin.
Crystal oscillator interface. XTAL_OUT is the output.
XTAL_IN is the input.
13, 19
GND
Power
Power supply ground.
14, 15
17, 18
Q3, Q2,
Q1, Q0
Output
Single-ended clock outputs. LVCMOS/LVTTL interface levels.
17Ω typical output impedance.
16
VDDO
Power
Output supply pin.
NOTE: Pullup and Pulldown refer to internal input resistors. See Table 2, Pin Characteristics, for typical values.
TABLE 2. PIN CHARACTERISTICS
Symbol
CIN
CPD
RPULLUP
RPULLDOWN
Parameter
Input Capacitance
Power Dissipation Capacitance
Input Pullup Resistor
Input Pulldown Resistor
ROUT
Output Impedance
Test Conditions
VDDO = 3.3V±5%
VDDO = 2.5V±5%
Minimum
Typical
4
8
51
51
17
21
Maximum
Units
pF
pF
kΩ
kΩ
Ω
Ω
840004AGI-01
2
REV. A OCTOBER 22, 2007