參數(shù)資料
型號: VSC7959
廠商: Vitesse Semiconductor Corporation.
元件分類: 限幅放大器
英文描述: 3.125Gb/s CML Limiting Amplifier with LOS Detect
中文描述: 3.125Gb / s的慢性骨髓性白血病與LOS檢測限幅放大器
文件頁數(shù): 7/10頁
文件大?。?/td> 96K
代理商: VSC7959
VITESSE
Advance Product Information
VSC7959
3.125Gb/s CML Limiting Amplifier with LOS Detect
G52358-0, Rev 2.0
02/09/01
Page 7
VITESSE
SEMICONDUCTOR CORPORATION
741 Calle Plano
Camarillo, CA 93012
Tel: (800) VITESSE
FAX: (805) 987-5896
Email: prodinfo@vitesse.com
Internet: www.vitesse.com
Detailed Description
The VSC7959 is a high speed limiting amplifier with Loss-of-Signal (LOS) detect. The device is designed
to operate with a 3.3V or 5V supply in SDH/SONET and Fibre Channel applications up to 3.125Gb/s. The
VSC7959 has current-mode logic (CML) outputs. The VSC7961 provides the same functionality as the
VSC7959 with positive emitter-coupled logic (PECL) outputs. The key features of the VSC7959 are Loss-of-
Signal (LOS) detect, output offset correction, output squelch, adjustable output levels, low power supply cur-
rent, and fast rise and fall times.
The inputs of the device provide 100
input impedance between IN+ and IN- and are intended to be DC-
coupled. The CML output circuits are designed to tolerate output impedance mismatches and may be AC- or
DC-coupled.
Loss of Signal (LOS) Detect
This features utilizes an RMS power detector with programmable LOS indicator to provide two outputs,
LOS and LOS. The input TH is used to set the threshold at which the loss of signal detector outputs, LOS and
LOS, change state. See the Loss of Signal Specifications (Table 3)
for setting the resistor value between TH and
ground. The Loss of Signal Truth Table (Table 4)
clarifies how LOS and SQUELCH interact.
Optional Squelch
Squelch is disabled when SQUELCH is not connected or is set to TTL low level. When SQUELCH is set to
TTL high level and LOS is asserted, the data outputs, OUT+ and OUT- are forced to static levels. If LOS is not
asserted, the outputs will not be squelched.
Offset Correction
This feature is provided to ensure that the offsets in the limiting amplifier coupled with its gain do not cause
the output buffer to give a false output. Because of the high gain of the amplifier, offset correction using a low-
frequency feedback loop reduces input offset. If no component is placed between pins CZ1 and CZ2, the low
frequency cut-off is 2MHz. If a 0.1
μ
F capacitor is placed between CZ1 and CZ2, the low frequency cut-off is
lowered to about 2kHz. For Fibre Channel and Gigabit Ethernet applications, leave pins CZ1 and CZ2 open. For
ATM/SONET and other scrambled non-return-to-zero (NRZ) applications, place a 0.1
μ
F capacitor between
CZ1 and CZ2. This maintains a one-decade separation between the lowest input frequency and the low fre-
quency cut-off. The low frequency cut-off of the offset correction loop is given by the following equation:
f
OC
= 43 / [2
π
* 35k (C
Z
+ 100pF)]
= 196
10
-6
/ (C
Z
+ 100pF)
= 196
10
-6
/ (0.1
μ
F + 100pF)
= 1.96kHz
相關(guān)PDF資料
PDF描述
VSC7959YD 3.125Gb/s CML Limiting Amplifier with LOS Detect
VSC7959W 3.125Gb/s CML Limiting Amplifier with LOS Detect
VSC7961 3.125Gb/s PECL Limiting Amplifier with LOS Detect
VSC7961W BOX AA CELL REMOTE ALMOND
VSC7961YD 3.125Gb/s PECL Limiting Amplifier with LOS Detect
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
VSC7959W 制造商:VITESSE 制造商全稱:Vitesse Semiconductor Corporation 功能描述:3.125Gb/s CML Limiting Amplifier with LOS Detect
VSC7959YD 制造商:VITESSE 制造商全稱:Vitesse Semiconductor Corporation 功能描述:3.125Gb/s CML Limiting Amplifier with LOS Detect
VSC7961 制造商:VITESSE 制造商全稱:Vitesse Semiconductor Corporation 功能描述:3.125Gb/s PECL Limiting Amplifier with LOS Detect
VSC7961W 制造商:VITESSE 制造商全稱:Vitesse Semiconductor Corporation 功能描述:3.125Gb/s PECL Limiting Amplifier with LOS Detect
VSC7961YD 制造商:VITESSE 制造商全稱:Vitesse Semiconductor Corporation 功能描述:3.125Gb/s PECL Limiting Amplifier with LOS Detect