参数资料
型号: GS1515-CTM
厂商: Electronic Theatre Controls, Inc.
英文描述: HDTV Serial Digital Reclocker
中文描述: 高清晰度电视串行数字时钟恢复器
文件页数: 7/17页
文件大小: 336K
代理商: GS1515-CTM
522 - 23 - 01
15
G
S
1
515
Fig. 27 Power Layer
Fig. 28 Bottom Copper Layer
EXTERNAL PCB AFFECTS
RETURN LOSS
In the application where the GS1515 directly drives a cable,
it is possible to achieve an output return loss (ORL) of about
17dB to 1.485GHz. Care should be taken with the PCB
layout. It is suggested to use the EB1515 as a reference
layout. The use of very small ‘608’ surface mount
components and short distances between the components
will help in designing high frequency circuits. Openings in
the ground plane helps reduce PCB parasitic capacitance.
For best matching, a 10nH inductor in parallel with a 75
resistor and a 1.5pF capacitor matches the 75
cable
impedance. The inductor and resistor cancel the parasitic
capacitance while the capacitor cancels the inductive effect
of the bond wire. In order to verify the performance of any
layout, a return loss measurement should be done by
shorting the inductor with a piece of wire,
without the
GS1515 installed.
Unless the artwork is an exact copy of the recommended
layout, every design should be verified for output return
loss. Changes in the layout should be tweaked until a return
loss of 25dB is attained while the GS1515 is not mounted
and LCOMP is shorted. Once the device is mounted, different
inductors
should
be
used
to
match
the
parasitic
capacitance of the IC. When the right inductor is used,
maximum return loss between 5MHz to 800MHz is
achievable. Then the shunt capacitor between of 0.5pF to
1.5pF should be tried to increase the return loss between
800MHz and 1.5GHz. The larger inductor causes slower
rise/fall time. The larger shunt capacitor causes a kink in the
output waveform. Thus, the waveform must be verified to
meet SMPTE 292M specifications.
Since there are two levels at the output, depending upon
the output state (logic high or low), measurement should be
done by latching the outputs in both states. Since the actual
output node voltages are different when a stream of data
passing as compared to the static situation created to
measure return loss, an interpolation is necessary.
See the
GS1508 Preliminary Data Sheet for more information.
Fig. 29 Compensated Output Return Loss at Logic HIGH
Fig. 30 Compensated Output Return Loss at Logic LOW
3
4
相关PDF资料
PDF描述
GS2008HET/R7 2 A, 800 V, SILICON, RECTIFIER DIODE
GS4576S09L-25 DDR DRAM, PBGA144
GS54180RK 1 ELEMENT, 18 uH, GENERAL PURPOSE INDUCTOR, SMD
GS54180RJ 1 ELEMENT, 18 uH, GENERAL PURPOSE INDUCTOR, SMD
GS54180BL 1 ELEMENT, 18 uH, GENERAL PURPOSE INDUCTOR, SMD
相关代理商/技术参数
参数描述
GS1522 制造商:GENNUM 制造商全称:GENNUM 功能描述:HDTV Serial Digital Serializer
GS1522_04 制造商:GENNUM 制造商全称:GENNUM 功能描述:HDTV Serial Digital Serializer
GS1522-CQR 制造商:Rochester Electronics LLC 功能描述: 制造商:Gennum Corporation 功能描述:
GS1522-CQRE3 制造商:Gennum Corporation 功能描述:Monolithic Bipolar Integrated Circuit 128-Pin MQFP
GS1524 制造商:GENNUM 制造商全称:GENNUM 功能描述:GS1524 HD-LINX-TM II Multi-Rate SDI Adaptive Cable Equalizer