THS7372 Datasheet, PDF (28/49 Pages) Texas Instruments – 4-Channel Video Amplifier with One CVBS and Three Full-HD Filters with 6-dB Gain

THS7372
SBOS578 – AUGUST 2011
APPLICATION INFORMATION
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The THS7372 is targeted for four-channel video output applications that require one standard-definition (SD)
video output buffer and three full-high definition (FHD) video output buffers. Although it can be used for
numerous other applications, the needs and requirements of the video signal are the most important design
parameters of the THS7372. Built on the revolutionary, complementary Silicon Germanium (SiGe) BiCom3X
process, the THS7372 incorporates many features not typically found in integrated video parts while consuming
very low power. The THS7372 includes the following features:
• Single-supply 2.7-V to 5-V operation with low total quiescent current of 23.4 mA at 3.3 V and
24.5 mA at 5 V
• Disable mode allows for shutting down individual SD/FHD blocks of amplifiers to save system power in
power-sensitive applications
• Input configuration accepting dc + level shift, ac sync-tip clamp, or ac-bias
– AC-biasing is allowed with the use of external pull-up resistors to the positive power supply
• Sixth-order, low-pass filter for DAC reconstruction or ADC image rejection:
– 9.5 MHz for NTSC, PAL, SECAM, and composite video (CVBS) signals
– 72 MHz for 1080p60 Y’/P’ _B/P’_R or G’B’R’ signals
• Individually-controlled Disable mode shuts down all amplifiers in each SD/FHD block to reduce quiescent
current to 0.1 μA
• Internally-fixed gain of 2-V/V (+6-dB) buffer that can drive two video lines with dc-coupling or traditional
ac-coupling
• Flow-through configuration using a TSSOP-14 package that complies with the latest lead-free
(RoHS-compatible) and green manufacturing requirements
OPERATING VOLTAGE
The THS7372 is designed to operate from 2.7 V to 5 V over the –40°C to +85°C temperature range. The impact
on performance over the entire temperature range is negligible as a result of the implementation of thin film
resistors and high-quality, low-temperature coefficient capacitors. The design of the THS7372 allows operation
down to 2.6 V, but it is recommended to use at least a 3-V supply to ensure that no issues arise with headroom
or clipping with 100% color-saturated CVBS signals. If only 75% color saturated CVBS is supported, then the
output voltage requirements are reduced to 2 V_PP on the output, allowing a 2.7-V supply to be utilized without
issues.
A 0.1-μF to 0.01-μF capacitor should be placed as close as possible to the power-supply pins. Failure to do so
may result in the THS7372 outputs ringing or oscillating. Additionally, a large capacitor (such as 22 μF to 100 μF)
should be placed on the power-supply line to minimize interference with 50-/60-Hz line frequencies.
INPUT VOLTAGE
The THS7372 input range allows for an input signal range from –0.2 V to approximately (V_S+ – 1.5 V). However,
because of the internal fixed gain of 2 V/V (+6 dB) and the internal input level shift of 150 mV (typical), the output
is generally the limiting factor for the allowable linear input range. For example, with a 5-V supply, the linear input
range is from –0.2 V to 3.5 V. However, because of the gain and level shift, the linear output range limits the
allowable linear input range to approximately –0.1 V to 2.3 V.
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Copyright © 2011, Texas Instruments Incorporated