参数资料
型号: SL28773ELI
厂商: Silicon Laboratories Inc
文件页数: 2/21页
文件大小: 0K
描述: IC CLOCK CK505 PCIE INTEL 32QFN
标准包装: 624
系列: EProClock®
类型: 时钟/频率发生器,多路复用器
PLL:
主要目的: Intel CPU 服务器
输入: 晶体
输出: HCSL,LVCMOS
电路数: 1
比率 - 输入:输出: 1:9
差分 - 输入:输出: 无/是
频率 - 最大: 133MHz
电源电压: 3.135 V ~ 3.465 V
工作温度: 0°C ~ 85°C
安装类型: *
封装/外壳: *
供应商设备封装: *
包装: *
SL28773
......................Document #: 001-08400 Rev ** Page 10 of 21
.
The SL28773 requires a Parallel Resonance Crystal. Substi-
tuting a series resonance crystal causes the SL28773 to
operate at the wrong frequency and violates the ppm specifi-
cation. For most applications there is a 300-ppm frequency
shift between series and parallel crystals due to incorrect
loading.
Crystal Loading
Crystal loading plays a critical role in achieving low ppm perfor-
mance. To realize low ppm performance, use the total capac-
itance the crystal sees to calculate the appropriate capacitive
loading (CL).
Figure 1 shows a typical crystal configuration using the two
trim capacitors. It is important that the trim capacitors are in
series with the crystal. It is not true that load capacitors are in
parallel with the crystal and are approximately equal to the
load capacitance of the crystal.
Calculating Load Capacitors
In addition to the standard external trim capacitors, consider
the trace capacitance and pin capacitance to calculate the
crystal loading correctly. Again, the capacitance on each side
is in series with the crystal. The total capacitance on both side
is twice the specified crystal load capacitance (CL). Trim
capacitors are calculated to provide equal capacitive loading
on both sides.
1
0
27M_NSS
27M_SS
-1.75%
1
0
1
27M_NSS
27M_SS
+/-0.5%
1
0
1
0
27M_NSS
27M_SS
+/-0.75%
10
11
N/A
11
00
N/A
11
01
N/A
11
10
N/A
11
N/A
B1b4
B1b3
B1b2
B1b1
Pin7
Pin 8
Spread
(%)
Table 5. Output Driver Status during CPU_STP#
CPU_STP# Asserted
SMBus OE Disabled
Single-ended Clocks
Stoppable
Running
Driven low
Non stoppable
Running
Differential Clocks
Stoppable
Clock driven high
Clock driven low
Clock# driven low
Non stoppable
Running
Table 6. Output Driver Status
All Single-ended Clocks
All Differential Clocks
w/o Strap
w/ Strap
Clock
Clock#
PD# = 0 (Power down)
Low
Hi-z
Low
Table 7. Crystal Recommendations
Frequency
(Fund)
Cut
Loading
Load Cap
Drive
(max.)
Shunt Cap
(max.)
Motional
(max.)
Tolerance
(max.)
Stability
(max.)
Aging
(max.)
14.31818 MHz
AT
Parallel
20 pF
0.1 mW
5 pF
0.016 pF
35 ppm
30 ppm
5 ppm
Figure 1. Crystal Capacitive Clarification
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SL28773ELIT 功能描述:时钟发生器及支持产品 Comm app w/PCIe requirements & Intel RoHS:否 制造商:Silicon Labs 类型:Clock Generators 最大输入频率:14.318 MHz 最大输出频率:166 MHz 输出端数量:16 占空比 - 最大:55 % 工作电源电压:3.3 V 工作电源电流:1 mA 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:QFN-56
SL28774ELC 功能描述:时钟发生器及支持产品 Shrink CK505 for Calpella platforms RoHS:否 制造商:Silicon Labs 类型:Clock Generators 最大输入频率:14.318 MHz 最大输出频率:166 MHz 输出端数量:16 占空比 - 最大:55 % 工作电源电压:3.3 V 工作电源电流:1 mA 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:QFN-56
SL28774ELCT 功能描述:时钟发生器及支持产品 Shrink CK505 for Calpella platforms RoHS:否 制造商:Silicon Labs 类型:Clock Generators 最大输入频率:14.318 MHz 最大输出频率:166 MHz 输出端数量:16 占空比 - 最大:55 % 工作电源电压:3.3 V 工作电源电流:1 mA 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:QFN-56
SL28774ELI 功能描述:时钟发生器及支持产品 Shrink CK505 for Calpella platforms RoHS:否 制造商:Silicon Labs 类型:Clock Generators 最大输入频率:14.318 MHz 最大输出频率:166 MHz 输出端数量:16 占空比 - 最大:55 % 工作电源电压:3.3 V 工作电源电流:1 mA 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:QFN-56
SL28774ELIT 功能描述:时钟发生器及支持产品 Shrink CK505 for Calpella platforms RoHS:否 制造商:Silicon Labs 类型:Clock Generators 最大输入频率:14.318 MHz 最大输出频率:166 MHz 输出端数量:16 占空比 - 最大:55 % 工作电源电压:3.3 V 工作电源电流:1 mA 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:QFN-56