DATASHEET
CLOCK DIVIDER
Description
The ICS544-01 is crystal oscillator module IC with
divide by 512 frequency output. It employs a 16.777216
MHz fundamental frequency crystal source oscillator to
generate 32.768 kHz output crystal oscillator output. In
addition a divide by 256, 64 and 32 options are also
provided through select pins. The chip has an OE pin
that tri-states the output and stops the oscillator circuits.
The ICS544-01 is a member of IDT’s ClockBlocks
TM
family of clock building blocks. See the ICS541 and
ICS542 for other clock dividers, and the ICS501, 502,
511, 512, and 525 for clock multipliers.
ICS544-01
Features
•
•
•
•
•
•
•
•
•
•
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Packaged in 8-pin SOIC
Pb-free package
IDT’s lowest cost clock divider
Easy to use with other generators and buffers
Input crystal at 16.777216MHz
Output clock duty cycle of 45/55
Output Enable
Advanced, low-power CMOS process
Operating voltage of 2.25 V to 3.6 V
Does not degrade phase noise - no PLL
Available in industrial temperature range
Block Diagram
VDD
S1, S0 (1:0)
Divider and
Selection
Circuitry
/32, /64
/256, /512,
X1
16.777216MHz
crystal input
CLK1
X2
Optional tuning
capacitors
GND
OE
IDT®
CLOCK DIVIDER
1
ICS544-01
REV B 051810
ICS544-01
CLOCK DIVIDER
CLOCK DIVIDER
Pin Assignment
X1/ICLK
X2
GND
S0
1
2
3
4
8
7
6
5
S1
VDD
OE
CLK
Clock Divider Table
S1
0
0
1
1
S0
0
1
0
1
CLK
Input/32
Input/64
Input/256
Input/512
0 = connect directly to ground
1 = connect directly to VDD
8-pin (150 mil) SOIC
Pin Descriptions
Pin
Number
1
2
3
4
5
6
7
8
Pin
Name
X1/ICLK
X2
GND
S0
CLK
OE
VDD
S1
Pin
Type
XI
Xo
Power
Input
Output
Input
Power
Input
Crystal input.
Pin Description
Connect to crystal for crystal input and leave open for clock input.
Connect to ground.
Select 0 for output clock. Connect to GND or VDD, per divider table above.
Internal pull-up resistor.
Clock output per table above. Internal Pull down resistor.
Output Enable.Tri-states output clock when low. Also shuts down the oscillator
circuit. Internal pull-up resistor. OE=1 normal operation.
Connect to 2.25 V to 3.6 V.
Select 1 for output clock. Connect to GND or VDD, per divider table above.
Internal pull-up resistor.
External Components
Series Termination Resistor
Ω
Decoupling Capacitor
As with any high-performance mixed-signal IC, the
ICS544-01 must be isolated from system power supply
noise to perform optimally.
A decoupling capacitor of 0.01µF must be connected
between VDD and the PCB ground plane.
Ω
Ω
On chip capacitors
connected from pins X1 to ground and X2 to ground to
optimize the initial accuracy. The value (in pf) of these
crystal caps equal (C
L
-12)*2 in this equation,
C
L
=crystal load capacitance in pf. For example, for a
crystal with a 16 pF load cap, each external crystal cap
would be 8 pF. [(16-12)x2]=8.
IDT®
CLOCK DIVIDER
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ICS544-01
REV B 051810
ICS544-01
CLOCK DIVIDER
CLOCK DIVIDER
PCB Layout Recommendations
For optimum device performance and lowest output
phase noise, the following guidelines should be
observed.
1) The 0.01µF decoupling capacitor should be mounted
on the component side of the board as close to the VDD
pin as possible. No vias should be used between
decoupling capacitor and VDD pin. The PCB trace to
VDD pin should be kept as short as possible, as should
the PCB trace to the ground via. Distance of the ferrite
bead and bulk decoupling from the device is less
critical.
2) To minimize EMI, the 33Ω series termination resistor
(if needed) should be placed close to the clock output.
3) An optimum layout is one with all components on the
same side of the board, minimizing vias through other
signal layers (the ferrite bead and bulk decoupling
capacitor can be mounted on the back). Other signal
traces should be routed away from the ICS544-01. This
includes signal traces just underneath the device, or on
layers adjacent to the ground plane layer used by the
device.
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the ICS544-01. These ratings,
which are standard values for IDT commercially rated parts, are stress ratings only. Functional operation of
the device at these or any other conditions above those indicated in the operational sections of the
specifications is not implied. Exposure to absolute maximum rating conditions for extended periods can
affect product reliability. Electrical parameters are guaranteed only over the recommended operating
temperature range.
Item
Supply Voltage, VDD
All Inputs and Outputs
Ambient Operating Temperature (commercial)
Ambient Operating Temperature (industrial)
Storage Temperature
Junction Temperature
Soldering Temperature
7V
Rating
-0.5 V to VDD+0.5 V
0 to +70° C
-40 to +85° C
-65 to +150° C
125° C
260° C
Recommended Operation Conditions
Parameter
Ambient Operating Temperature (commercial)
Ambient Operating Temperature (industrial)
Power Supply Voltage (measured in respect to GND)
Min.
0
-40
2.25
Typ.
Max.
+70
+85
3.6
Units
°
C
°
C
V
IDT®
CLOCK DIVIDER
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ICS544-01
REV B 051810
ICS544-01
CLOCK DIVIDER
CLOCK DIVIDER
DC Electrical Characteristics
Unless stated otherwise,
VDD = 2.25 V to 3.6 V, C
L
=15pF ±5%,
Ambient Temperature -40° C to +85° C
Parameter
Operating Voltage
Input High Voltage
Input Low Voltage
Output High Voltage
Output Low Voltage
Operating Supply Current
Operating Supply Current
Standby Current
Short Circuit Current
Input Capacitance
Nominal Output Impedance
Internal Pull-up Resistor
Symbol
VDD
V
IH
V
IL
V
OH
V
OL
I
DD
I
DD
I
SB
I
OS
C
IN
Z
O
Rpup
Conditions
S0, S1, OE, ICLK
S0, S1, OE, ICLK
I
OH
= -2 mA
I
OL
= 2 mA
VDD =2.25 V - 2.75 V
VDD= 2.75 V - 3.6 V
OE=0
Min.
2.25
0.7VDD
Typ.
Max.
3.6
0.3VDD
Units
V
V
V
V
V
mA
mA
ua
mA
pF
Ω
kΩ
VDD-0.4
VDD-0.15
0.15
0.3
0.5
±40
0.4
0.6
1
10
4
20
420
S0, S1, OE
at VDD/2
OE, S1, S0
AC Electrical Characteristics
Unless stated otherwise,
VDD = 2.25 V to 3.6 V±5%, C
L
=15pF ±5%,
Ambient Temp -40° C to +85° C
Parameter
Input Frequency, clock input
Output Rise Time
Output Fall Time
Duty Cycle
Output Enable Delay Time
Output Disable Delay Time
Symbol
t
OR
t
OF
t
OE
t
OD
Conditions
VDD = 3.3 V
0.1VDD to 0.9VDD
0.9VDD to 0.1VDD
at VDD/2
OE going high to CLK
output valid
OE going low to CLK
output invalid
Min.
0
Typ.
16.777216
0.2
0.2
Max.
1
1
55
2
2
Units
MHz
μs
μs
%
μs
μs
45
49 to 51
Thermal Characteristics
Parameter
Thermal Resistance Junction to
Ambient
Symbol
θ
JA
θ
JA
θ
JA
θ
JC
Conditions
Still air
1 m/s air flow
3 m/s air flow
Min.
Typ.
150
140
120
40
Max. Units
°
C/W
°
C/W
°
C/W
°
C/W
Thermal Resistance Junction to Case
IDT®
CLOCK DIVIDER
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ICS544-01
REV B 051810
ICS544-01
CLOCK DIVIDER
CLOCK DIVIDER
Marking Diagram
(ICS554M-01LF)
8
5
Marking Diagram
(ICS554MI-01LF)
8
5
554M01LF
######
YYWW
1
4
1
554MI01L
######
YYWW
4
Notes:
1. ###### is the lot number.
2. YYWW is the last two digits of the year and week that the part was assembled.
3. “L” or “LF” denotes Pb (lead) free package.
4. “I” denotes industrial temperature range.
5. Bottom Marking: (origin)
Origin = country of origin if not USA.
IDT®
CLOCK DIVIDER
5
ICS544-01
REV B 051810
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