ICS85357-11
4:1
OR
2:1, C
RYSTAL
O
SCILLATOR
-
TO
-3.3V
LVPECL / ECL M
ULTIPLEXER
G
ENERAL
D
ESCRIPTION
The ICS85357-11 is a 4:1 or 2:1, Crystal
Oscillator-to-3.3V LVPECL / ECL Multiplexer . The ICS85357-
11 has 4 selectable crystal inputs. The device can support
10MHz to 27MHz parallel resonant crystals by connecting
external capacitors between XTALIN/XTALOUT and ground.
The select pins have internal pulldown resistors and leaving
one input unconnected (pulled to logic low by the internal
resistor) will transform the device into a 2:1 multiplexer. The
SEL1 lead is the most significant line and the binary number
applied to the select pins will select the same numbered data
input (i.e., 00 selects XTALIN0/XTALOUT0).
F
EATURES
•
One differential 3.3V LVPECL output
•
4:1 or 2:1 Crystal Oscillator Multiplexer
•
Supports parallel resonant crystals with a frequency range
of 10MHz to 27MHz. The oscillator circuit is optimized for
parallel resonant mode, and will require external capacitance
•
Maximum output frequency: 27MHz
•
LVCMOS/LVTTL SEL0 and SEL1 inputs have
internal pulldown resistors
•
LVPECL mode operating voltage supply range:
V
CC
= 3.135V to 3.465V, V
EE
= 0V
•
ECL mode operating voltage supply range:
V
CC
= 0V, V
EE
= -3.135V to -3.465V
•
0°C to 70°C ambient operating temperature
•
Industrial temperature information available upon request
•
Available in both standard (R0HS 5) and lead-free
(RoHS 6) packages
B
LOCK
D
IAGRAM
P
IN
A
SSIGNMENT
V
CC
XTALIN0
XTALOUT0
XTALIN1
XTALOUT1
XTALIN2
XTALOUT2
XTALIN3
XTALOUT3
V
EE
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
V
CC
SEL1
SEL0
V
CC
Q0
nQ0
V
CC
nc
nc
V
EE
XTALIN0
OSC
XT
ALOUT0
XTALIN1
OSC
XT
ALOUT1
XTALIN2
OSC
XT
ALOUT2
XTALIN3
OSC
XT
ALOUT3
SEL1 SEL0
11
10
01
Q0
nQ0
00
ICS85357-11
20-Lead TSSOP
4.40mm x 6.50mm x 0.92mm body package
G Package
Top View
85357AG-11
www.idt.com
1
REV. D OCTOBER 4, 2010
ICS85357-11
4:1
OR
2:1, C
RYSTAL
O
SCILLATOR
-
TO
-3.3V
LVPECL / ECL M
ULTIPLEXER
T
ABLE
1. P
IN
D
ESCRIPTIONS
Number
1, 14, 17, 20
2
3
4
5
6
7
8
9
10, 11
12, 13
15, 16
18
19
Name
V
CC
XTALIN0
XTALOUT0
XTALIN1
XTALOUT1
XTALIN2
XTALOUT2
XTALIN3
XTALOUT3
V
EE
nc
nQ0, Q0
SEL0
SEL1
Power
Input
Input
Input
Input
Input
Input
Input
Input
Power
Unused
Output
Input
Input
Pulldown
Pulldown
Type
Description
Positive supply pins.
Parallel resonant cr ystal input.
Parallel resonant cr ystal input.
Parallel resonant cr ystal input.
Parallel resonant cr ystal input.
Parallel resonant cr ystal input.
Parallel resonant cr ystal input.
Parallel resonant cr ystal input.
Parallel resonant cr ystal input.
Negative supply pins.
No connect.
Differential clock outputs. LVPECL interface levels.
Clock select input. LVCMOS / LVTTL interface levels.
Clock select input. LVCMOS / LVTTL interface levels.
NOTE:
Pullup
and
Pulldown
refer to internal input resistors. See Table 2, Pin Characteristics, for typical values.
T
ABLE
2. P
IN
C
HARACTERISTICS
Symbol
C
IN
R
PULLDOWN
Parameter
Input Capacitance
Input Pulldown Resistor
Test Conditions
Minimum
Typical
4
51
Maximum
Units
pF
kΩ
T
ABLE
3A. C
ONTROL
I
NPUT
F
UNCTION
T
ABLE
Inputs
SEL1
0
0
1
1
SEL0
0
1
0
1
Clock Out
CLK
XTALIN0, XTALOUT0
XTALIN1, XTALOUT1
XTALIN2, XTALOUT2
XTALIN3, XTALOUT3
85357AG-11
www.idt.com
2
REV. D OCTOBER 4, 2010
ICS85357-11
4:1
OR
2:1, C
RYSTAL
O
SCILLATOR
-
TO
-3.3V
LVPECL / ECL M
ULTIPLEXER
A
BSOLUTE
M
AXIMUM
R
ATINGS
Supply Voltage, V
CC
Inputs, V
I
Outputs, V
O
Package Thermal Impedance,
θ
JA
Storage Temperature, T
STG
4.6V
-0.5V to V
CC
+ 0.5 V
-0.5V to V
CC
+ 0.5V
73.2°C/W (0 lfpm)
-65°C to 150°C
NOTE: Stresses beyond those listed under Absolute
Maximum Ratings may cause permanent damage to the
device. These ratings are stress specifications only. Functional
operation of product at these conditions or any conditions be-
yond those listed in the
DC Characteristics
or
AC Character-
istics
is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect product reliability.
T
ABLE
4A. P
OWER
S
UPPLY
DC C
HARACTERISTICS
,
V
CC
= 3.3V±5%, T
A
= 0°C
TO
70°C
Symbol
V
CC
I
EE
Parameter
Positive Supply Voltage
Power Supply Current
Test Conditions
Minimum
3.135
Typical
3.3
Maximum
3.465
50
Units
V
mA
T
ABLE
4B. LVCMOS / LVTTL DC C
HARACTERISTICS
,
V
CC
= 3.3V±5%, T
A
= 0°C
TO
70°C
Symbol
V
IH
V
IL
I
IH
I
IL
Parameter
Input High Voltage
Input Low Voltage
Input High Current
Input Low Current
SEL0, SEL1
SEL0, SEL1
SEL0, SEL1
SEL0, SEL1
V
CC
= V
IN
= 3.465V
V
CC
= 3.465V, V
IN
= 0V
-5
Test Conditions
Minimum
2
-0.3
Typical
Maximum
V
CC
+ 0.3
0.8
150
Units
V
V
µA
µA
T
ABLE
4C. LVPECL DC C
HARACTERISTICS
,
V
CC
= 3.3V±5%, T
A
=0°C
TO
70°C
Symbol
V
OH
V
OL
V
SWING
Parameter
Output High Voltage; NOTE 1
Output Low Voltage; NOTE 1
Peak-to-Peak Output Voltage Swing
Test Conditions
Minimum
V
CC
- 1.4
V
CC
- 2.0
0.6
Typical
Maximum
V
CC
- 0.9
V
CC
- 1.7
1.0
Units
V
V
V
NOTE 1: Outputs terminated with 50
Ω
to V
CC
- 2V.
T
ABLE
5. C
RYSTAL
C
HARACTERISTICS
Parameter
Mode of Oscillation / cut
Frequency
Equivalent Series Resistance (ESR)
Shunt Capacitance
Test Conditions
Minimum
10
Typical Maximum
27
70
7
Units
MHz
Ω
pF
Fundamental / Parallel Resonant
T
ABLE
6. AC C
HARACTERISTICS
,
V
CC
= 3.3V±5%, T
A
=0°C
TO
70°C
Symbol Parameter
f
MAX
t
R
/ t
F
odc
Output Frequency Range
Output Rise/Fall Time
Output Duty Cycle; NOTE 1, 2
20% to 80%
Test Conditions
Minimum
10
300
47
Typical
Maximum
27
700
53
Units
MHz
ps
%
oscTOL Cr ystal Oscillator Tolerance; NOTE 1
±20
ppm
All parameters measured at 25MHz unless noted otherwise.
NOTE 1: Measured using C1 = 22pF and C2 = 27pF in parallel with 18pF cr ystals. Refer to Cr ystal Input Interface in the
Application Section.
NOTE 2: This parameter is defined in accordance with JEDEC Standard 65.
85357AG-11
www.idt.com
3
REV. D OCTOBER 4, 2010
ICS85357-11
4:1
OR
2:1, C
RYSTAL
O
SCILLATOR
-
TO
-3.3V
LVPECL / ECL M
ULTIPLEXER
P
ARAMETER
M
EASUREMENT
I
NFORMATION
2V
V
CC
Qx
SCOPE
80%
80%
V
SW I N G
LVPECL
nQx
V
EE
Clock
Outputs
20%
t
R
t
F
20%
-1.3V ± 0.165V
3.3V O
UTPUT
L
OAD
AC T
EST
C
IRCUIT
O
UTPUT
R
ISE
/F
ALL
T
IME
nQ0
Q0
Pulse Width
t
PERIOD
odc =
t
PW
t
PERIOD
O
UTPUT
D
UTY
C
YCLE
/P
ULSE
W
IDTH
/P
ERIOD
85357AG-11
www.idt.com
4
REV. D OCTOBER 4, 2010
ICS85357-11
4:1
OR
2:1, C
RYSTAL
O
SCILLATOR
-
TO
-3.3V
LVPECL / ECL M
ULTIPLEXER
A
PPLICATION
I
NFORMATION
C
RYSTAL
I
NPUT
I
NTERFACE
A crystal can be characterized for either series or parallel mode
operation. The ICS85357-11 has a built-in crystal oscillator circuit.
This interface can accept either a series or parallel crystal without
additional components and generate frequencies with accuracy
suitable for most applications. Additional accuracy can be
achieved by adding two small capacitors C1 and C2 as shown in
Figure 1.
Typical results using parallel 18pF crystals are shown
in Table 7.
XTAL_IN
C1
22p
X1
18pF Parallel Crystal
XTAL_OUT
C2
27p
F
IGURE
1. Crystal Input Interface
Table 7. T
YPICAL
R
ESULTS
Crystal Frequency
(MHz)
14.31818
15.00
16.66
19.44
24.00
OF
C
RYSTAL
I
NPUT
I
NTERFACE
F
REQUENCY
F
INE
T
UNING
C2
(pF)
27
27
27
27
27
Measured Output Frequency
(MHz)
14.318011
14.999862
16.660162
19.440081
24.000183
Accuracy
(PPM)
-12
-9
10
4
8
Duty Cycle
(%)
47.46
47.70
47.70
46.85
46.00
C1
(pF)
22
22
22
22
22
85357AG-11
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5
REV. D OCTOBER 4, 2010
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