參數(shù)資料
型號(hào)： THS7375IPW
廠商： TEXAS INSTRUMENTS INC
元件分類： 音頻／視頻放大
英文描述： VIDEO AMPLIFIER, PDSO14
封裝： GREEN, PLASTIC, TSSOP-14
文件頁(yè)數(shù)： 20/39頁(yè)
文件大?。?/td> 973K
代理商： THS7375IPW
75 W
VideoOut
DAC
R2
53.6 W
R1
21.5 W
75 W
5.6V/V
THS7375
V
INPUT
0.44V
PP
V
DAC
0.615V
100%SaturatedCVBS
PP
2.46V
PP
1.23V
PP
www.ti.com
SBOS449A – SEPTEMBER 2008 – REVISED JANUARY 2011
These filters have been specified by design to
One final advantage of the THS7375 over a passive
account for process and temperature variations to
filter is power dissipation. A DAC driving a video line
maintain proper filter characteristics. This architecture
must be able to drive a 37.5-
load—the receiver
maintains a low channel-to-channel time delay, which
75-
resistor and the 75- source impedance
is required for proper video signal performance.
matching resistor next to the DAC to maintain the
source impedance requirement. This approach forces
Another benefit of the THS7375 over a passive RLC
the DAC to drive at least 1.25 VP (100% saturation
filter is the input and output impedance. The input
CVBS)/37.5
= 33.3 mA. A DAC is a current
impedance
presented
to
the
DAC
may
vary
steering element and this amount of current flows
significantly with a passive network and may cause
internally to the DAC even if the output is 0 V. Thus,
voltage variations over frequency. The THS7375
power dissipation in the DAC may be very high,
input impedance is 800 k
, and only the 2-pF input
especially when four channels are being driven. With
capacitance plus the PCB trace capacitance impacts
a high input impedance and the capability to drive up
the input impedance. As such, the voltage variation
to two video lines, utilizing the THS7375 can reduce
appearing at the DAC output is better controlled with
the
DAC
power
dissipation
significantly.
This
a fixed termination resistor and the high input
reduction occurs because the resistance the DAC is
impedance buffer of the THS7375.
driving can be substantially increased. It is common
to set this driving resistance in a DAC by a
On the output side of the filter, a passive filter also
current-setting resistor on the device. Thus, the
has a large impedance variation over frequency. The
resistance can be 300
or more, substantially
EIA770 specifications requires the return loss be at
reducing the current drive demands from the DAC
least 25 dB over the video frequency range of usage.
and saving a substantial amount of power. For
For a video system, this condition implies the source
example, a 3.3-V four-channel DAC dissipates 440
impedance—which includes the source and the
mW for the steering current capability alone (four
series resistor and the filter—must be better than 75
channels × 33.3 mA × 3.3 V) if it must drive a 37.5-
+9/–8
. The THS7375 is an operational amplifier
load. With a 300-
load, the DAC power dissipation
that approximates an ideal voltage source. A voltage
as a result of current steering current would only be
source is desirable because the output impedance is
55 mW (four channels × 4.16 mA × 3.3 V).
very low and can source and sink current. To properly
match the transmission line characteristic impedance
Reducing System Gain
of a video line, a 75-
series resistor is placed on the
output. To minimize reflections and to maintain a
The THS7375 has a built-in gain of 5.6 V/V, or 14.95
good return loss, this output resistance must maintain
dB. While this gain matches the needs of many of
a 75-
impedance. A passive filter impedance
Texas Instruments' video processors, including the
variation cannot ensure this consistent performance
DaVinci family of products, the gain can be easily
while the THS7375 has about 1.4-
of output
reduced to meet other needs. The easiest and most
impedance at 5-MHz. Thus, the system is much
effective method of adjusting the gain lower is to
better matched with a THS7375 as compared to a
simply use a resistor divider on the input to the
passive filter.
THS7375, as shown in Figure 54. This solution uses
resistors R1 and R2 to accomplish two requirements:
1. Terminate
the
video
DAC
with
the
proper
resistance, and
2. Form a resistor divider in before the THS7375
input.
Figure 54. Configuring the THS7375 with 4-V/V (12dB) Gain
Copyright 2008–2011, Texas Instruments Incorporated
27
Product Folder Link(s): THS7375
相關(guān)PDF資料
PDF描述
THS7375IPWG4 VIDEO AMPLIFIER, PDSO14
THS7375IPWRG4 VIDEO AMPLIFIER, PDSO14
THS770012IRGET SPECIALTY ANALOG CIRCUIT, PQCC24
THS8083-95CPZP SPECIALTY CONSUMER CIRCUIT, PQFP100
THS8083APZP SPECIALTY CONSUMER CIRCUIT, PQFP100
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
THS7375IPWG4 功能描述:視頻放大器 4Ch SDTV Video Amp w/6th order fltr RoHS:否 制造商:ON Semiconductor 通道數(shù)量:4 電源類型: 工作電源電壓:3.3 V, 5 V 電源電流: 最小工作溫度: 最大工作溫度: 封裝 / 箱體:TSSOP-14 封裝:Reel
THS7375IPWR 功能描述:視頻放大器 4Ch SDTV Video Amp RoHS:否 制造商:ON Semiconductor 通道數(shù)量:4 電源類型: 工作電源電壓:3.3 V, 5 V 電源電流: 最小工作溫度: 最大工作溫度: 封裝 / 箱體:TSSOP-14 封裝:Reel
THS7375IPWRG4 功能描述:視頻放大器 4Ch SDTV Video Amp w/6th order fltr RoHS:否 制造商:ON Semiconductor 通道數(shù)量:4 電源類型: 工作電源電壓:3.3 V, 5 V 電源電流: 最小工作溫度: 最大工作溫度: 封裝 / 箱體:TSSOP-14 封裝:Reel
THS7376 制造商:TI 制造商全稱:Texas Instruments 功能描述:4-Channel Video Amplifier with One SD and Three HD 8th-Order Filters with 6-dB Gain
THS7376IPW 制造商:Texas Instruments 功能描述:4-Channel Video Amplifier 1SD 3HD 制造商:Texas Instruments 功能描述:IC SDTV VIDEO AMP 4-CH 14-TSSOP
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*