THS7365 Datasheet, PDF (32/53 Pages) Texas Instruments – 6-Channel Video Amplifier with 3-SD and 3-HD Sixth-Order Filters and 6-dB Gain

THS7365
SBOS467 – MARCH 2009.................................................................................................................................................................................................. www.ti.com
APPLICATION INFORMATION
The THS7365 is targeted for six-channel video output
applications that require three standard-definition
(SD) video output buffers and three high-definition
(HD) 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 THS7365. Built
on the revolutionary, complementary Silicon
Germanium (SiGe) BiCom3X process, the THS7365
incorporates many features not typically found in
integrated video parts while consuming very low
power. The THS7365 includes the following features:
• Single-supply 2.7-V to 5-V operation with low total
quiescent current of 20.7 mA at 3.3 V and 21.6
mA at 5 V
• Disable mode allows for shutting down individual
SD/HD 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, composite
video (CVBS), S-Video Y’/C’, 480i/576i,
Y’/P’_B/P’_R, and G’B’R’ (R’G’B’) signals
– 36 MHz for 720p, 1080i, or up to 1080p30
Y’/P’_B/P’_R or G’B’R’ signals; also allows up to
XGA (1024 × 768 at 60 Hz) R'G'B' video
• Individually-controlled Bypass mode bypasses the
low-pass filters for each SD/HD block of amplifiers
– SD bypass mode features 130-MHz and
100-V/µs performance
– HD bypass mode features 250-MHz and
500-V/µs performance
• Individually-controlled Disable mode shuts down
all amplifiers in each SD/HD block to reduce
quiescent current to less than 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-20
package that complies with the latest lead-free
(RoHS-compatible) and green manufacturing
requirements
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 THS7365 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 THS7365 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.
INPUT OVERVOLTAGE PROTECTION
The THS7365 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 115.
+V_S
External
Input/Output
Pin
Internal
Circuitry
Figure 115. Internal ESD Protection
OPERATING VOLTAGE
The THS7365 is designed to operate from 2.7 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 THS7365
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.
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