max9654aub Maxim Integrated Products, Inc., max9654aub Datasheet - Page 9

• Manufacturer Part Number: max9654aub
• Description: 3.3v, Hd/sd Triple-channel Filter Amplifiers With Shutdown
• Manufacturer: Maxim Integrated Products, Inc.

42MHz, which is well beyond the 30MHz specification
for high-definition video signals. The typical attenuation
is 30dB at 74.25MHz, which is the sample clock rate for
the first generation of high-definition video DACs. The
typical attenuation is 50dB at 109MHz, which is also a
popular sample clock rate.
The MAX9654 has a six-pole Butterworth filter with a
typical passband (±1dB) of 8.5MHz, which makes the
device suitable for standard-definition video signals
from all sources (e.g., broadcast and DVD). Broadcast
video signals are channel limited: NTSC signals have
4.2MHz bandwidth and PAL signals have 5MHz band-
width. Video signals from a DVD player, however, are
not channel limited, so the bandwidth of DVD video sig-
nals can approach the Nyquist limit of 6.75MHz.
Recommendation ITU-R BT.601-5 specifies 13.5MHz as
the sampling rate for standard-definition video.
Therefore, the maximum bandwidth of the signal is
6.75MHz. To ease the filtering requirements, most mod-
ern video systems oversample by two times, clocking
the video current DAC at 27MHz. The typical attenua-
tion is 57dB at 27MHz.
The output amplifiers have a fixed gain of 2V/V, and
their rail-to-rail output stages are capable of driving
Figure 1. (A) MAX9653/MAX9654 Input Circuit in Shutdown
Mode; (B) MAX9653/MAX9654 Equivalent Input Circuit in
Shutdown Mode
3.3V, HD/SD Triple-Channel Filter Amplifiers
IN_
IN_
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222k
V
667k
333k
DD
V
DD
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MAX9653
MAX9654
MAX9653
MAX9654
Video Amplifier
SD Video Filter
back-terminated 75Ω loads. The output load can be
either DC-coupled or AC-coupled, in which case, use
an AC-coupling capacitor of at least 220µF.
The luma signal at YOUT swings between 0.3V and
2.3V approximately. The color difference signals are
centered around 1.32V.
The back-termination resistor in a typical application
limits the short-circuit current if an external short is
applied to the system. Additionally, the output ampli-
fiers have built-in short-circuit protection to prevent
accidental damage when the outputs are directly short-
ed to either supply or ground for short times.
The MAX9654 passband is selectable between SD and
HD. Pulling SD/HD low results in an SD passband, and
pulling SD/HD high results in a HD passband. The
MAX9652/MAX9653 have a fixed HD passband.
The MAX9653/MAX9654 feature a shutdown mode. Pull
SHDN high for normal operation. Pull SHDN low to put the
devices in shutdown, reducing quiescent current to 12µA
typically and placing the outputs in high impedance.
The quiescent power consumption and average power
consumption of the MAX9652/MAX9653/MAX9654 are
low because of the 3.3V operation. Quiescent power
consumption is defined when the parts operate without a
load. In this case, the MAX9652/MAX9653/MAX9654
consume approximately 95mW. Average power con-
sumption, which is defined when the MAX9652/
MAX9653/MAX9654 drive a 150Ω load to ground with
color bars, is about 200mW. Table 1 shows the power
consumption with different HD video signals. The supply
voltage is 3.3V. The outputs drive 150Ω loads to ground.
Table 1. Power Consumption of the
MAX9652/MAX9653/MAX9654 with
Different HD Video Signals
VIDEO SIGNAL
All black screen
All white screen
Color bars
Applications Information
with Shutdown
Short-Circuit Protection
POWER CONSUMPTION (mW)
Power Consumption
Digital Control
181
209
200
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