ICS ICS8523BGILF

ICS8523I
Integrated
Circuit
Systems, Inc.
LOW SKEW, 1-TO-4
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
GENERAL DESCRIPTION
FEATURES
The ICS8523I is a low skew, high performance 1-to-4 Differential-to-HSTL fanout buffer
HiPerClockS™
and a member of the HiPerClockS™family of High
Performance Clock Solutions from ICS. The
ICS8523I has two selectable clock inputs. The
CLK, nCLK pair can accept most standard differential input
levels. The PCLK, nPCLK pair can accept LVPECL, CML, or
SSTL input levels. The clock enable is internally synchronized
to eliminate runt pulses on the outputs during asynchronous
assertion/deassertion of the clock enable pin.
• 4 differential HSTL compatible outputs
ICS
• Selectable diffferential CLK, nCLK or LVPECL clock inputs
• CLK, nCLK pair can accept the following differential
input levels: LVDS, LVPECL, HSTL, SSTL, HCSL
• PCLK, nPCLK supports the following input types:
LVPECL, CML, SSTL
• Maximum output frequency: 650MHz
• Translates any single-ended input signal to HSTL
levels with resistor bias on nCLK input
Guaranteed output and part-to-part skew characteristics
make the ICS8523I ideal for those applications demanding
well defined performance and repeatability.
• Output skew: 50ps (maximum)
• Part-to-part skew: 250ps (maximum)
• Propagation delay: 1.6ns (maximum)
• 3.3V core, 1.8V output operating supply
• Lead-Free package available
• -40°C to 85°C ambient operating temperature
BLOCK DIAGRAM
PIN ASSIGNMENT
D
CLK_EN
GND
CLK_EN
CLK_SEL
CLK
nCLK
PCLK
nPCLK
nc
nc
VDD
Q
LE
CLK
nCLK
PCLK
nPCLK
CLK_SEL
0
1
Q0
nQ0
Q1
nQ1
Q2
nQ2
20
19
18
17
16
15
14
13
12
11
Q0
nQ0
VDDO
Q1
nQ1
Q2
nQ2
VDDO
Q3
nQ3
ICS8523I
Q3
nQ3
8523BGI
1
2
3
4
5
6
7
8
9
10
20-Lead TSSOP
6.5mm x 4.4mm x 0.92mm body package
G Package
Top View
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1
REV. C SEPTEMBER 16, 2004
ICS8523I
Integrated
Circuit
Systems, Inc.
LOW SKEW, 1-TO-4
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
TABLE 1. PIN DESCRIPTIONS
Number
Name
Type
1
GND
Power
2
CLK_EN
Input
3
CLK_SEL
Input
4
CLK
Input
5
nCLK
Input
6
PCLK
Input
7
nPCLK
Input
8, 9
nc
Unused
Description
Power supply ground.
Synchronizing clock enable. When HIGH, clock outputs follow clock
input. When LOW, Q outputs are forced low, nQ outputs are forced
Pullup
high. LVCMOS / LVTTL interface levels.
Clock select input. When HIGH, selects differential PCLK, nPCLK
Pulldown inputs. When LOW, selects CLK, nCLK inputs.
LVCMOS / LVTTL interface levels.
Pulldown Non-inver ting differential clock input.
Pullup
Inver ting differential clock input.
Pulldown Non-inver ting differential LVPECL clock input.
Pullup
Inver ting differential LVPECL clock input.
No connect.
10
VDD
Power
Core supply pin.
11, 12
nQ3, Q3
Output
Differential output pair. HSTL interface levels.
13, 18
VDDO
Power
Output supply pins.
14, 15
nQ2, Q2
Output
Differential output pair. HSTL interface levels.
16, 17
nQ1, Q1
Output
Differential output pair. HSTL interface levels.
19, 20
nQ0, Q0
Output
Differential output pair. HSTL interface levels.
NOTE: Pullup and Pulldown refer to internal input resistors. See Table 2, Pin Characteristics, for typical values.
TABLE 2. PIN CHARACTERISTICS
Symbol
Parameter
Test Conditions
Minimum
Typical
Maximum
Units
CIN
Input Capacitance
4
pF
RPULLUP
Input Pullup Resistor
51
KΩ
RPULLDOWN
Input Pulldown Resistor
51
KΩ
8523BGI
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2
REV. C SEPTEMBER 16, 2004
ICS8523I
Integrated
Circuit
Systems, Inc.
LOW SKEW, 1-TO-4
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
TABLE 3A. CONTROL INPUT FUNCTION TABLE
Inputs
CLK_EN
CLK_SEL
Outputs
Selected Source
Q0:Q3
nQ0:nQ3
0
0
CLK, nCLK
Disabled; LOW
Disabled; HIGH
0
1
PCLK, nPCLK
Disabled; LOW
Disabled; HIGH
1
0
CLK, nCLK
Enabled
Enabled
1
1
PCLK, nPCLK
Enabled
Enabled
After CLK_EN switches, the clock outputs are disabled or enabled following a rising and falling input clock edge
as shown in Figure 1.
In the active mode, the state of the outputs are a function of the CLK , nCLK and PCLK, nPCLK inputs as described
in Table 3B.
Enabled
Disabled
nCLK, nPCLK
CLK, PCLK
CLK_EN
nQ0:nQ3
Q0:Q3
FIGURE 1. CLK_EN TIMING DIAGRAM
TABLE 3B. CLOCK INPUT FUNCTION TABLE
Inputs
Outputs
CLK or PCLK
nCLK or nPCLK
0
1
0
1
Input to Output Mode
Polarity
HIGH
Differential to Differential
Non Inver ting
LOW
Differential to Differential
Non Inver ting
LOW
HIGH
Single Ended to Differential
Non Inver ting
HIGH
LOW
Single Ended to Differential
Non Inver ting
HIGH
LOW
Single Ended to Differential
Inver ting
LOW
HIGH
Single Ended to Differential
Inver ting
Q0:Q3
nQ0:nQ3
0
LOW
1
HIGH
Biased; NOTE 1
Biased; NOTE 1
Biased; NOTE 1
0
Biased; NOTE 1
1
NOTE 1: Please refer to the Application Information section, "Wiring the Differential Input to Accept Single Ended Levels".
8523BGI
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3
REV. C SEPTEMBER 16, 2004
ICS8523I
Integrated
Circuit
Systems, Inc.
LOW SKEW, 1-TO-4
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, VDD
4.6V
Inputs, VI
-0.5V to VDD + 0.5V
Outputs, IO
Continuous Current
Surge Current
50mA
100mA
Package Thermal Impedance, θJA
73.2°C/W (0 lfpm)
Storage Temperature, TSTG
-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 beyond those listed in the DC Characteristics or AC Characteristics is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect product reliability.
TABLE 4A. POWER SUPPLY DC CHARACTERISTICS, VDD = 3.3V±5%, VDDO = 1.8V±0.2V, TA = 0°C TO 70°C
Symbol
Parameter
VDD
Core Power Supply Voltage
Test Conditions
VDDO
Output Power Supply Voltage
IDD
Power Supply Current
Minimum
Typical
Maximum
Units
3.135
3.3
3.465
V
1.6
1.8
2.0
V
55
mA
Maximum
Units
TABLE 4B. LVCMOS / LVTTL DC CHARACTERISTICS, VDD = 3.3V±5%, VDDO = 1.8V±0.2V, TA = 0°C TO 70°C
Symbol
Parameter
Test Conditions
Minimum
Typical
VIH
Input High Voltage
CLK_EN, CLK_SEL
2
VDD + 0.3
V
VIL
Input Low Voltage
CLK_EN, CLK_SEL
-0.3
0.8
V
IIH
Input High Current
5
µA
IIL
Input Low Current
CLK_EN
VDD = VIN = 3.465V
CLK_SEL
VDD = VIN = 3.465V
CLK_EN
VDD = 3.465V, VIN = 0V
-150
150
µA
µA
CLK_SEL
VDD = 3.465V, VIN = 0V
-5
µA
TABLE 4C. DIFFERENTIAL DC CHARACTERISTICS, VDD = 3.3V±5%, VDDO = 1.8V±0.2V, TA = 0°C TO 70°C
Symbol
Parameter
IIH
Input High Current
IIL
Input Low Current
Maximum
Units
nCLK
VDD = VIN = 3.465V
Test Conditions
5
µA
CLK
VDD = VIN = 3.465V
150
µA
nCLK
VDD = 3.465V, VIN = 0V
-150
µA
CLK
VDD = 3.465V, VIN = 0V
-5
µA
VPP
Minimum
Typical
Peak-to-Peak Input Voltage
0.15
Common Mode Input Voltage;
0.5
VCMR
NOTE 1, 2
NOTE 1: For single ended applications the maximum input voltage for CLK and nCLK is VDD + 0.3V.
NOTE 2: Common mode voltage is defined as VIH.
8523BGI
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4
1.3
V
VDD - 0.85
V
REV. C SEPTEMBER 16, 2004
ICS8523I
Integrated
Circuit
Systems, Inc.
LOW SKEW, 1-TO-4
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
TABLE 4D. LVPECL DC CHARACTERISTICS, VDD = 3.3V±5%, VDDO = 1.8V±0.2V, TA = 0°C TO 70°C
Symbol
Parameter
Maximum
Units
PCLK
VDD = VIN = 3.465V
Test Conditions
150
µA
nPCLK
VDD = VIN = 3.465V
5
µA
IIH
Input High Current
IIL
Input Low Current
V PP
Peak-to-Peak Input Voltage
Minimum
Typical
PCLK
VDD = 3.465V, VIN = 0V
-5
µA
nPCLK
VDD = 3.465V, VIN = 0V
-150
µA
0.3
Common Mode Input Voltage; NOTE 1, 2
1.5
VCMR
NOTE 1: Common mode voltage is defined as VIH.
NOTE 2: For single ended applications the maximum input voltage for PCLK and nPCLK is VDD + 0.3V.
1
V
VDD
V
TABLE 4D. HSTL DC CHARACTERISTICS, VDD = 3.3V±5%, VDDO = 1.8V±0.2V, TA = 0°C TO 70°C
Symbol Parameter
Output High Voltage;
VOH
NOTE 1
Output Low Voltage;
VOL
NOTE 1
VOX
Test Conditions
Output Crossover Voltage
Minimum
Maximum
Units
0.9
1.4
V
0
0.4
V
40% x (VOH - VOL) + VOL
60% x (VOH - VOL) + VOL
V
0.6
1.3
V
Peak-to-Peak
Output Voltage Swing
NOTE 1: Outputs terminated with 50Ω to ground.
VSWING
Typical
TABLE 5. AC CHARACTERISTICS, VDD = 3.3V±5%, VDDO = 1.8V±0.2V, TA = 0°C TO 70°C
Symbol
Parameter
Test Conditions
Minimum
IJ 650MHz
1.0
Typical
Maximum
Units
650
MHz
1.6
ns
50
ps
fMAX
Output Frequency
tPD
Propagation Delay; NOTE 1
t sk(o)
Output Skew; NOTE 2, 4
t sk(pp)
Par t-to-Par t Skew; NOTE 3, 4
250
ps
tR
Output Rise Time
20% to 80% @ 50MHz
300
700
ps
tF
Output Fall Time
20% to 80% @ 50MHz
300
700
ps
55
%
odc
Output Duty Cycle
45
All parameters measured at 500MHz unless noted otherwise.
The cycle to cycle jitter on the input will equal the jitter on the output. The par t does not add jitter.
NOTE 1: Measured from the differential input crossing point to the differential output crossing point.
NOTE 2: Defined as skew between outputs at the same supply voltage and with equal load conditions.
Measured at output differential cross points.
NOTE 3: Defined as skew between outputs on different devices operating at the same supply voltages
and with equal load conditions. Using the same type of inputs on each device, the outputs are measured
at the differential cross points.
NOTE 4: This parameter is defined in accordance with JEDEC Standard 65.
8523BGI
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5
REV. C SEPTEMBER 16, 2004
ICS8523I
Integrated
Circuit
Systems, Inc.
LOW SKEW, 1-TO-4
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
PARAMETER MEASUREMENT INFORMATION
3.3V±5%
1.8V±0.2V
V DD
V DD
Qx
SCOPE
VDDO
nCLK, nPCLK
V
HSTL
Cross Points
PP
V
CMR
CLK, PCLK
nQx
GND
GND = 0V
3.3V/1.8V OUTPUT LOAD AC TEST CIRCUIT
DIFFERENTIAL INPUT LEVEL
nQx
Qx
PART 1
nQx
Qx
Qy
PART 2
nQy
nQy
Qy
t sk(pp)
t sk(o)
OUTPUT SKEW
PART-TO-PART SKEW
nCLK,
nPCLK
CLK,
PCLK
80%
80%
VSW I N G
Clock
Outputs
nQ0:nQ3
20%
20%
tF
tR
Q0:Q3
tPD
OUTPUT RISE/FALL TIME
PROPAGATION DELAY
nQ0:nQ3
Q0:Q3
Pulse Width
t
odc =
odc & tPERIOD
8523BGI
PERIOD
t PW
t PERIOD
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6
REV. C SEPTEMBER 16, 2004
ICS8523I
Integrated
Circuit
Systems, Inc.
LOW SKEW, 1-TO-4
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
APPLICATION INFORMATION
WIRING THE DIFFERENTIAL INPUT TO ACCEPT SINGLE ENDED LEVELS
Figure 2 shows how the differential input can be wired to accept
single ended levels. The reference voltage V_REF = VDD/2 is
generated by the bias resistors R1, R2 and C1. This bias circuit
should be located as close as possible to the input pin. The ratio
of R1 and R2 might need to be adjusted to position the V_REF in
the center of the input voltage swing. For example, if the input
clock swing is only 2.5V and VDD = 3.3V, V_REF should be 1.25V
and R2/R1 = 0.609.
VDD
R1
1K
CLK_IN
+
V_REF
C1
0.1uF
R2
1K
FIGURE 2. SINGLE ENDED SIGNAL DRIVING DIFFERENTIAL INPUT
8523BGI
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7
REV. C SEPTEMBER 16, 2004
ICS8523I
Integrated
Circuit
Systems, Inc.
LOW SKEW, 1-TO-4
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
DIFFERENTIAL CLOCK INPUT INTERFACE
The CLK /nCLK accepts LVDS, LVPECL, HSTL, SSTL, HCSL
and other differential signals. Both VSWING and VOH must meet the
VPP and VCMR input requirements. Figures 3A to 3E show interface examples for the HiPerClockS CLK/nCLK input driven by
the most common driver types. The input interfaces suggested
here are examples only. Please consult with the vendor of the
driver component to confirm the driver termination requirements.
For example in Figure 3A, the input termination applies for ICS
HiPerClockS HSTL drivers. If you are using an HSTL driver from
another vendor, use their termination recommendation.
3.3V
3.3V
3.3V
1.8V
Zo = 50 Ohm
CLK
Zo = 50 Ohm
CLK
Zo = 50 Ohm
nCLK
Zo = 50 Ohm
LVPECL
nCLK
HiPerClockS
Input
LVHSTL
ICS
HiPerClockS
LVHSTL Driver
R1
50
R1
50
HiPerClockS
Input
R2
50
R2
50
R3
50
FIGURE 3A. HIPERCLOCKS CLK/NCLK INPUT DRIVEN
ICS HIPERCLOCKS HSTL DRIVER
FIGURE 3B. HIPERCLOCKS CLK/NCLK INPUT DRIVEN
3.3V LVPECL DRIVER
BY
3.3V
3.3V
3.3V
3.3V
3.3V
R3
125
BY
R4
125
Zo = 50 Ohm
LVDS_Driv er
Zo = 50 Ohm
CLK
CLK
R1
100
Zo = 50 Ohm
nCLK
LVPECL
R1
84
HiPerClockS
Input
nCLK
Receiv er
Zo = 50 Ohm
R2
84
FIGURE 3C. HIPERCLOCKS CLK/NCLK INPUT DRIVEN
3.3V LVPECL DRIVER
FIGURE 3D. HIPERCLOCKS CLK/NCLK INPUT DRIVEN
3.3V LVDS DRIVER
BY
BY
3.3V
3.3V
3.3V
LVPECL
Zo = 50 Ohm
C1
Zo = 50 Ohm
C2
R3
125
R4
125
CLK
nCLK
R5
100 - 200
R6
100 - 200
R1
84
HiPerClockS
Input
R2
84
R5,R6 locate near the driver pin.
FIGURE 3E. HIPERCLOCKS CLK/NCLK INPUT DRIVEN
3.3V LVPECL DRIVER WITH AC COUPLE
8523BGI
BY
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8
REV. C SEPTEMBER 16, 2004
ICS8523I
Integrated
Circuit
Systems, Inc.
LOW SKEW, 1-TO-4
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
LVPECL CLOCK INPUT INTERFACE
here are examples only. If the driver is from another vendor,
use their termination recommendation. Please consult with
the vendor of the driver component to confirm the driver termination requirements.
The PCLK /nPCLK accepts LVPECL, CML, SSTL and other
differential signals. Both VSWING and VOH must meet the VPP
and VCMR input requirements. Figures 4A to 4F show interface
examples for the HiPerClockS PCLK/nPCLK input driven by
the most common driver types. The input interfaces suggested
3.3V
3.3V
3.3V
3.3V
3.3V
R1
50
CML
Zo = 50 Ohm
R2
50
Zo = 50 Ohm
PCLK
PCLK
R1
100
Zo = 50 Ohm
nPCLK
nPCLK
Zo = 50 Ohm
HiPerClockS
PCLK/nPCLK
HiPerClockS
PCLK/nPCLK
CML Built-In Pullup
FIGURE 4A. HIPERCLOCKS PCLK/nPCLK INPUT DRIVEN
BY AN OPEN COLLECTOR CML DRIVER
FIGURE 4B. HIPERCLOCKS PCLK/nPCLK INPUT DRIVEN
BY A BUILT-IN PULLUP CML DRIVER
3.3V
3.3V
3.3V
3.3V
3.3V
R3
125
3.3V
R4
125
Zo = 50 Ohm
3.3V LVPECL
Zo = 50 Ohm
C1
Zo = 50 Ohm
C2
R3
84
R4
84
PCLK
PCLK
Zo = 50 Ohm
nPCLK
LVPECL
R1
84
nPCLK
HiPerClockS
Input
R5
100 - 200
R2
84
FIGURE 4C. HIPERCLOCKS PCLK/nPCLK INPUT DRIVEN
BY A 3.3V LVPECL DRIVER
R6
100 - 200
R1
125
FIGURE 4D. HIPERCLOCKS PCLK/nPCLK INPUT DRIVEN
BY A 3.3V LVPECL DRIVER WITH AC COUPLE
3.3V
2.5V
3.3V
3.3V
3.3V
2.5V
R3
120
SSTL
Zo = 50 Ohm
R4
120
C1
LVDS
Zo = 60 Ohm
R4
1K
R3
1K
PCLK
PCLK
R5
100
Zo = 60 Ohm
nPCLK
R1
120
C2
nPCLK
Zo = 50 Ohm
HiPerClockS
PCLK/nPCLK
R1
1K
R2
120
FIGURE 4E. HIPERCLOCKS PCLK/nPCLK INPUT DRIVEN
BY AN SSTL DRIVER
8523BGI
HiPerClockS
PCLK/nPCLK
R2
125
HiPerClockS
PCL K/n PC LK
R2
1K
FIGURE 4F. HIPERCLOCKS PCLK/nPCLK INPUT DRIVEN
BY A 3.3V LVDS DRIVER
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9
REV. C SEPTEMBER 16, 2004
ICS8523I
Integrated
Circuit
Systems, Inc.
LOW SKEW, 1-TO-4
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
SCHEMATIC EXAMPLE
Figure 5 shows a schematic example of the ICS8523I. In this
example, the input is driven by an ICS HiPerClockS HSTL driver.
The decoupling capacitors should be physically located near the
power pin. For ICS8523I, the unused clock outputs can be left
floating.
Zo = 50
+
Zo = 50
3.3V
R2
50
R1
50
R12
1K
U3
1.8V
Zo = 50
Zo = 50 Ohm
Zo = 50 Ohm
R11
1K
LVHSTL Driver
R9
50
3.3V
1
2
3
4
5
6
7
8
9
10
R10
50
GND
CLK_EN
CLK_SEL
CLK
nCLK
PCLK
nPCLK
NC
NC
VDD
Q0
nQ0
VDDO
Q1
nQ1
Q2
nQ2
VDDO
Q3
nQ3
20
19
18
17
16
15
14
13
12
11
+
1.8V
Zo = 50
1.8V
R4
50
R3
50
C1
0.1u 8523
Zo = 50
+
1.8V
Zo = 50
C2
0.1u
-
C3
0.1u
R6
50
R5
50
Zo = 50
+
Zo = 50
R8
50
R7
50
FIGURE 5. ICS8523I HSTL BUFFER SCHEMATIC EXAMPLE
8523BGI
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10
REV. C SEPTEMBER 16, 2004
ICS8523I
Integrated
Circuit
Systems, Inc.
LOW SKEW, 1-TO-4
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
POWER CONSIDERATIONS
This section provides information on power dissipation and junction temperature for the ICS8523I.
Equations and example calculations are also provided.
1. Power Dissipation.
The total power dissipation for the ICS8523I is the sum of the core power plus the power dissipated in the load(s).
The following is the power dissipation for VDD = 3.3V + 5% = 3.465V, which gives worst case results.
NOTE: Please refer to Section 3 for details on calculating power dissipated in the load.
•
•
Power (core)MAX = VDD_MAX * IDD_MAX = 3.465V * 55mA = 190.6mW
Power (outputs)MAX = 32.6mW/Loaded Output pair
If all outputs are loaded, the total power is 4 * 32.6mW = 130.4mW
Total Power_MAX (3.465V, with all outputs switching) = 190.6mW + 130.4mW = 321mW
2. Junction Temperature.
Junction temperature, Tj, is the temperature at the junction of the bond wire and bond pad and directly affects the reliability of the
device. The maximum recommended junction temperature for HiPerClockSTM devices is 125°C.
The equation for Tj is as follows: Tj = θJA * Pd_total + TA
Tj = Junction Temperature
θJA = Junction-to-Ambient Thermal Resistance
Pd_total = Total Device Power Dissipation (example calculation is in section 1 above)
TA = Ambient Temperature
In order to calculate junction temperature, the appropriate junction-to-ambient thermal resistance θJA must be used. Assuming a
moderate air flow of 200 linear feet per minute and a multi-layer board, the appropriate value is 66.6°C/W per Table 6 below.
Therefore, Tj for an ambient temperature of 85°C with all outputs switching is:
85°C + 0.321W * 66.6°C/W = 106.4°C. This is well below the limit of 125°C.
This calculation is only an example. Tj will obviously vary depending on the number of loaded outputs, supply voltage, air flow,
and the type of board (single layer or multi-layer).
TABLE 6. THERMAL RESISTANCE θJA
FOR
20-PIN TSSOP, FORCED CONVECTION
θJA by Velocity (Linear Feet per Minute)
Single-Layer PCB, JEDEC Standard Test Boards
Multi-Layer PCB, JEDEC Standard Test Boards
0
200
500
114.5°C/W
73.2°C/W
98.0°C/W
66.6°C/W
88.0°C/W
63.5°C/W
NOTE: Most modern PCB designs use multi-layered boards. The data in the second row pertains to most designs.
8523BGI
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11
REV. C SEPTEMBER 16, 2004
ICS8523I
Integrated
Circuit
Systems, Inc.
LOW SKEW, 1-TO-4
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
3. Calculations and Equations.
The purpose of this section is to derive the power dissipated into the load.
HSTL output driver circuit and termination are shown in Figure 6.
VDDO
Q1
VOUT
RL
50Ω
FIGURE 6. HSTL DRIVER CIRCUIT
AND
TERMINATION
To calculate worst case power dissipation into the load, use the following equations which assume a 50Ω load.
Pd_H is power dissipation when the output drives high.
Pd_L is the power dissipation when the output drives low.
Pd_H = (V
OH_MIN
Pd_L = (V
/R ) * (V
L
-V
DDO_MAX
/R ) * (V
OL_MAX
L
DDO_MAX
)
OH_MIN
-V
)
OL_MAX
Pd_H = (0.9V/50Ω) * (2V -0.9V) = 19.8mW
Pd_L = (0.4V/50Ω) * (2V - 0.4V) = 12.8mW
Total Power Dissipation per output pair = Pd_H + Pd_L = 32.6mW
8523BGI
www.icst.com/products/hiperclocks.html
12
REV. C SEPTEMBER 16, 2004
ICS8523I
Integrated
Circuit
Systems, Inc.
LOW SKEW, 1-TO-4
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
RELIABILITY INFORMATION
TABLE 7.
θJAVS. AIR FLOW TABLE FOR 20 LEAD TSSOP
θJA by Velocity (Linear Feet per Minute)
Single-Layer PCB, JEDEC Standard Test Boards
Multi-Layer PCB, JEDEC Standard Test Boards
0
200
500
114.5°C/W
73.2°C/W
98.0°C/W
66.6°C/W
88.0°C/W
63.5°C/W
NOTE: Most modern PCB designs use multi-layered boards. The data in the second row pertains to most designs.
TRANSISTOR COUNT
The transistor count for ICS8523I is: 472
8523BGI
www.icst.com/products/hiperclocks.html
13
REV. C SEPTEMBER 16, 2004
ICS8523I
Integrated
Circuit
Systems, Inc.
PACKAGE OUTLINE - G SUFFIX
FOR
LOW SKEW, 1-TO-4
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
20 LEADP TSSOP
TABLE 8. PACKAGE DIMENSIONS
Millimeters
SYMBOL
Minimum
N
A
Maximum
20
--
1.20
A1
0.05
0.15
A2
0.80
1.05
b
0.19
0.30
c
0.09
0.20
D
6.40
6.60
E
E1
6.40 BASIC
4.30
e
4.50
0.65 BASIC
L
0.45
α
0°
8°
aaa
--
0.10
0.75
Reference Document: JEDEC Publication 95, MS-153
8523BGI
www.icst.com/products/hiperclocks.html
14
REV. C SEPTEMBER 16, 2004
ICS8523I
Integrated
Circuit
Systems, Inc.
LOW SKEW, 1-TO-4
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
TABLE 9. ORDERING INFORMATION
Part/Order Number
Marking
Package
Count
Temperature
ICS8523BGI
ICS8523BGI
20 lead TSSOP
72 per tube
-40°C to 85°C
ICS8523BGIT
ICS8523BGI
20 lead TSSOP on Tape and Reel
2500
-40°C to 85°C
ICS8523BGILF
ICS8523BGILF
72 per tube
-40°C to 85°C
ICS8523BGILFT
ICS8523BGILF
20 lead "Lead-Free" TSSOP
20 lead "Lead-Free" TSSOP on
Tape and Reel
2500
-40°C to 85°C
The aforementioned trademark, HiPerClockS™ is a trademark of Integrated Circuit Systems, Inc. or its subsidiaries in the United States and/or other countries.
While the information presented herein has been checked for both accuracy and reliability, Integrated Circuit Systems, Incorporated (ICS) assumes no responsibility for either its use or for infringement
of any patents or other rights of third parties, which would result from its use. No other circuits, patents, or licenses are implied. This product is intended for use in normal commercial applications.
Any other applications such as those requiring extended temperature range, high reliability, or other extraordinary environmental requirements are not recommended without additional processing by
ICS. ICS reserves the right to change any circuitry or specifications without notice. ICS does not authorize or warrant any ICS product for use in life support devices or critical medical instruments.
8523BGI
www.icst.com/products/hiperclocks.html
15
REV. C SEPTEMBER 16, 2004
ICS8523I
Integrated
Circuit
Systems, Inc.
LOW SKEW, 1-TO-4
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
REVISION HISTORY SHEET
Rev
Table
Page
B
T5
5
AC Characteristics table. tPD row, changed Min. from 1.2ns to 1.0ns.
1/11/02
1
Revised Features section, Bullet 1,6 - took out 1.8V
5/6/02
B
B
T2
C
T4D
C
T9
8523BGI
8 - 10
2
4
5
11 - 12
1
9
15
Description of Change
Date
In the Application Information section, added Schematic Examples
Pin Characteristics Table - changed CIN 4pF max. to 4pF typical.
Absolute Maximum Ratings - changed Output rating.
HSTL DC Characteristics Table - changed VOH 1V min. to 0.9V min.
Power Considerations - changed Total Power Dissipation to reflect VOH change.
Calculations changed due to new Total Power Dissipation.
Changed LVHSTL to HSTL throughout data sheet.
Added Lead-Free bullet to Features section.
Updated LVPECL Clock Input Interface section.
Added Lead-Free Par t Number to Ordering Information TAble.
www.icst.com/products/hiperclocks.html
16
10/28/02
6/23/03
9/16/04
REV. C SEPTEMBER 16, 2004