THS7303 Datasheet, PDF (20/43 Pages) Texas Instruments – 3-Channel Low Power Video Amplifier with I2C Control, Selectable Filters, 6-dB Gain, SAG Correction, 2:1 Input MUX, and Selectable Input Bias Modes

THS7303
SLOS479 – OCTOBER 2005
APPLICATION INFORMATION
www.ti.com
The THS7303 is targeted for 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
THS7303. Built on the complimentary silicon germanium (SiGe) BiCom-3 process, the THS7303 incorporates
many features not typically found in integrated video parts while consuming low power. Each channel
configuration is completely independent of the other channels. This allows for configurations for each channel to
be dictated by the end user and not the device. This results in a highly flexible system for most video systems.
The THS7303 contains the following features:
• I²C Interface for easy interfacing to the system.
• Single-supply 2.7-V to 5-V operation with low total quiescent current of 16.6 mA with 3.3-V supply and 18.9
mA with 5-V supply.
• 2:1 input MUX.
• Input configuration accepting dc, dc + 135 mV shift, ac bias, or ac sync-tip clamp selection.
• Selectable 5^th order, low-pass filter for DAC reconstruction or ADC image rejection :
– 9-MHz for SDTV NTSC and 480i, PAL/SECAM and 576i, S-Video, and G'B'R' (R'G'B') signals.
– 16-MHz for EDTV 480p and 576p Y’P’_BP’_R signals, G’B’R’, and VGA signals.
– 35-MHz for HDTV 720p and 1080i Y’P’_BP’_R signals, G’B’R’, and SVGA/XGA signals.
– Bypass mode for passing HDTV 1080p Y’P’_BP’_R, G’B’R’, and SXGA/UXGA signals.
• Internal fixed gain of 2 V/V (6 dB) buffer that can drive 2 video lines with dc coupling, traditional ac coupling,
or SAG corrected ac coupling.
• Disable mode which reduces quiescent current to as low as 0.1-µA or a mute function that keeps the
THS7303 powered on, but does not allow a signal to pass through.
• Signal flow-through configuration using a 20-pin TSSOP package that complies with the latest lead-free
(RoHS compatible) and green manufacturing requirements.
OPERATING VOLTAGE
The THS7303 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 due to the implementation of thin film resistors and
low-temperature coefficient capacitors.
The power supply pins should have a 0.1-µF to 0.01-µF capacitor placed as close as possible to these pins.
Failure to do so may result in the THS7303 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 issues with 50/60 Hz line frequencies.
INPUT VOLTAGE
The THS7303 input range allows for an input signal range from ground to (V_S+– 1.4 V). But, due to the internal
fixed gain of 2 V/V (6 dB), the output is the limiting factor for the allowable linear input range. For example, with a
5-V supply, the linear input range is from GND to 3.6 V. But due to the gain, the linear output range limits the
allowable linear input range to be from GND to a maximum of 2.5 V.
INPUT OVERVOLTAGE PROTECTION
The THS7303 is built using a high-speed complementary bipolar and CMOS process. The internal junction
breakdown voltages are 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 58.
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