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參數(shù)資料
| 型號(hào)： | SY89534LHZTR |
| 廠商： | MICREL INC |
| 元件分類： | 時(shí)鐘及定時(shí) |
| 英文描述： | 89534 SERIES, PLL BASED CLOCK DRIVER, 13 TRUE OUTPUT(S), 0 INVERTED OUTPUT(S), PQFP64 |
| 封裝： | LEAD FREE, TQFP-64 |
| 文件頁數(shù)： | 14/15頁 |
| 文件大小： | 106K |
| 代理商： | SY89534LHZTR |
8
Precision Edge
SY89534/35L
Micrel, Inc.
M9999-110308
hbwhelp@micrel.com or (408) 955-1690
FUNCTIONAL DESCRIPTION
precision PLL driven by a differential or single-ended reference
input. For users who wish to supply a crystal input, please use
the SY89532L or SY89533L. The PLL output is sent to three
banks of outputs. Each bank has its own programmable
frequency divider, and the design is optimized to provide very
low skew between banks, and very low jitter.
PLL Programming and Operation
The internal VCO range is 600MHz to 1000MHz, and the
feedback ratio is selectable via the MSEL divider control (M3:0
pins). The feedback ratio can be changed without powering
the chip down. The PLL output is fed to three banks of outputs:
Bank A, Bank B, and Bank C. Banks A and C each have two
differential LVPECL output pairs. Bank B has nine differential
output pairs. On the SY89534L, Bank B is LVPECL. On the
SY89535L, Bank B is LVDS.
Each bank has a separate frequency divider circuit that can
be reprogrammed on the fly. The FSEL_x0:2 (where x is A, B,
or C) pins control the divider value. The FSEL divider can be
programmed in ratios from 2 to 18, and the outputs of Banks
A, B, and C can be synchronized after programming by
pulsing the OUT_SYNC pin HIGH-LOW-HIGH.
To determine the correct settings for SY89534/35L follow
these steps:
1. Refer to the
“Suggested Selections for Specific Customer
Applications” section for common applications, as well as the
formula used to compute the output frequency.
2. Determine the desired output frequency, such as
66MHz.
3. Choose a reference input frequency between 14MHz
and 20MHz. The user can also choose a higher input frequency,
and use the PSEL pre-divider to divide it down to the 14MHz
to 20MHz range. In this example, we choose 18MHz for the
reference input frequency. This results in an input/output ratio
of 66/18.
4. Refer to the
“Feedback Divide Select Table” and the
“Post-Divide Frequency Select Table” to find values for MSEL
and FSEL such that MSEL/FSEL equals the same 66/18 ratio.
In this example, values of MSEL=44 and FSEL=12 work.
5. Make sure that REFCLK
÷ PSEL × MSEL is between
600MHz and 1000MHz.
The user may need to experiment with different REFCLK
input frequencies to satisfy these requirements.
470pF
Loop
Filter
Loop
Reference
330
0.2
F
Figure 1. External Loop Filter Connection
External Loop Filter Considerations
The SY89534/35L features an external PLL loop filter that
allows the user to tailor the PLL’s behavior to their application
and operating environment. We recommend using ceramic
capacitors with NPO or X7R dielectric, as they have very low
effective series resistance. For applications that require ultra-
low cycle-to-cycle jitter, use the components shown in Figure
1. The PLL loop bandwidth is a function of feedback divider
ratio, and the external loop filter allows the user to compensate.
For instance, the PLL’s loop bandwidth can be decreased by
using a smaller resistor in the loop filter. This results in less
noise from the PLL input, but potentially more noise from the
VCO. Refer to
“AC Electrical Characteristics” for target PLL
loop bandwidth. The designer should take care to keep the
loop filter components on the same side of the board and as
close as possible to the SY89534/35L’s LOOP_REF and
LOOP_FILTER pins. To insure minimal noise pick-up on the
loop filter, it is desirable to cut away the ground plane directly
underneath the loop filter component pads and traces.
However, the benefit may not be significant in all applications
and one must be careful to not alter the characteristic
impedance of nearby traces.
Power Supply Filtering Techniques
As with any high-speed integrated circuit, power supply
filtering is very important. At a minimum, V
CCA, VCC_Logic,
and all V
CCO pins should be individually connected using a via
to the power supply plane, and separate bypass capacitors
should be used for each pin. To achieve optimal jitter
performance, each power supply pin should use separate
instances of the circuit shown in Figure 2.
*For VCC_Analog,VCC_TTL, VCC1,
use ferrite bead = 200mA, 0.45
DC,
Murata P/N BLM21A1025
*For VCC_OUT use ferrite bead = 3A, 0.025
DC,
Murata, P/N BLM31P005
*Component size: 0805
1
F
22
F
0.01
F
Ferrite Bead*
“Power Supply”
side
“Device”
side
VCC
Pins
Figure 2. Power Supply Filtering
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相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| SY89535L | 制造商:MICREL 制造商全稱:Micrel Semiconductor 功能描述:3.3V, PRECISION, 33MHz to 500MHz PROGRAMMABLE LVPECL AND HSTL BUS CLOCK SYNTHESIZER |
| SY89535LHC | 功能描述:IC SYNTHESIZR LVPECL/LVDS 64TQFP RoHS:否 類別:集成電路 (IC) >> 時(shí)鐘/計(jì)時(shí) - 時(shí)鐘發(fā)生器，PLL，頻率合成器 系列:Precision Edge® 產(chǎn)品變化通告:Product Discontinuation 04/May/2011 標(biāo)準(zhǔn)包裝:96 系列:- 類型:時(shí)鐘倍頻器，零延遲緩沖器 PLL:帶旁路 輸入:LVTTL 輸出:LVTTL 電路數(shù):1 比率 - 輸入:輸出:1:8 差分 - 輸入:輸出:無/無 頻率 - 最大:133.3MHz 除法器/乘法器:是/無 電源電壓:3 V ~ 3.6 V 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:16-TSSOP（0.173"，4.40mm 寬） 供應(yīng)商設(shè)備封裝:16-TSSOP 包裝:管件 其它名稱:23S08-5HPGG |
| SY89535LHCTR | 制造商:MICREL 制造商全稱:Micrel Semiconductor 功能描述:3.3V, PRECISION, 33MHz to 500MHz PROGRAMMABLE LVPECL AND LVDS BUS CLOCK SYNTHESIZER |
| SY89535LHH | 制造商:MICREL 制造商全稱:Micrel Semiconductor 功能描述:3.3V, PRECISION, 33MHz to 500MHz PROGRAMMABLE LVPECL AND LVDS BUS CLOCK SYNTHESIZER |
| SY89535LHHTR | 制造商:MICREL 制造商全稱:Micrel Semiconductor 功能描述:3.3V, PRECISION, 33MHz to 500MHz PROGRAMMABLE LVPECL AND LVDS BUS CLOCK SYNTHESIZER |
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