THS7374 Datasheet, PDF (17/37 Pages) Texas Instruments – 4-Channel SDTV Video Amplifier with 6th-Order Filters and 6-dB Gain

THS7374
www.ti.com....................................................................................................................................................................................................... SLOS590 – JULY 2008
APPLICATION INFORMATION
The THS7374 is targeted for standard definition video
output buffer applications. 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 THS7374. Built
on the revolutionary complementary Silicon
Germanium (SiGe) BiCom3X process, the THS7374
incorporates many features not typically found in
integrated video parts while consuming very low
power. The THS7374 has the following features:
• Single-supply 3 V to 5 V operation with low total
quiescent current of 9.6-mA at 3.3 V and 10-mA at
5 V.
• 0.1µA disable mode allows for shutting down the
THS7374 to save system power in
power-sensitive applications.
• Input configuration accepts dc + level shift, ac
sync-tip clamp, or ac-bias.
• AC-biasing is allowed with the use of a single
external pull-up resistor to the positive power
supply.
• Sixth-order low-pass filter for DAC reconstruction
or ADC image rejection:
– 9.5-MHz for NTSC, PAL, SECAM, composite
(CVBS), s-video Y’C’, 480i/576i Y’P’_BP’_R,
G’B’R’, and SCART signals.
• Bypass mode bypasses the low-pass filter with a
150-MHz bandwidth and 130-V/µs slew rate
amplifier
• Internal fixed gain of 2 V/V (+6 dB) buffer that can
drive two video lines per channel with dc-coupling
or traditional ac-coupling.
• Signal flow-through configuration in a TSSOP-14
package that complies with the latest lead-free
(RoHS-compatible) and green manufacturing
requirements.
Place a 0.1-µF to 0.01-µF capacitor as close as
possible to the power-supply pins. Failure to do so
may result in ringing or oscillating at the THS7374
outputs. Additionally, a large capacitor (such as 22 µF
to 100 µF) should be placed on the power-supply line
to minimize interference with 50-Hz/60-Hz line
frequencies.
INPUT VOLTAGE
The THS7374 input range allows for an input signal
range from –0.2 V to about (V_S+ – 1.5 V). However,
because of the internal fixed gain of 2 V/V (+6 dB)
and the internal level shift of 150 mV nominal, 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. As a
result of the gain and level shift, the linear output
range limits the allowable linear input range to be
from about –0.1 V to 2.3 V.
INPUT OVERVOLTAGE PROTECTION
The THS7374 is built using a very high-speed
complementary bipolar and CMOS process. The
internal junction breakdown voltages are relatively
low for these very small geometry devices. These
breakdowns are reflected in the Absolute Maximum
Ratings table. All input and output device pins are
protected with internal ESD protection diodes to the
power supplies, as shown in Figure 35.
+V_S
External
Input/Output
Pin
Internal
Circuitry
OPERATING VOLTAGE
The THS7374 is designed to operate from 3-V to 5-V
over a –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 THS7374
allows operation down to 2.85 V, but it is
recommended to use at least a 3-V supply to ensure
no issues with headroom or clipping.
Figure 35. Internal ESD Protection
These diodes provide moderate protection to input
overdrive voltages above and below the supplies as
well. The protection diodes can typically support 30
mA of continuous current when overdriven.
Copyright © 2008, Texas Instruments Incorporated
Product Folder Link(s): THS7374
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