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APPLICATION INFORMATION

OPERATING VOLTAGE

INPUT VOLTAGE

THS7327

SLOS502 – SEPTEMBER 2006

The THS7327 is targeted for RGB + HV sync video buffer applications. Although it can be used for numerous

other applications, the needs and requirements of the video signal is the most important design parameter of the

THS7327. Built on the complimentary Silicon Germanium (SiGe) BiCom-3 process, the THS7327 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 ANY configuration for each

channel to be dictated by the end user rather than the device — resulting in a highly flexible system. The

THS7327 has the following features:

•

•

Single-supply 2.7-V to 5-V operation with low quiescent current of 100-mA at 3.3-V

•

2:1 input MUX

•

Input configuration accepting dc, dc + shift, ac bias, or ac sync-tip clamp selection.

•

Unity Gain Buffer path to drive ADC/Scalar/Decoder.

•

– 9-MHz for SDTV NTSC and 480i, PAL/SECAM and 576i, and S-Video signals.

– 75-MHz for HDTV 1080p and R’G’B’ SXGA signals.

– Bypass mode for passing R'G'B' UXGA, QXGA or higher signals.

•

Monitor Pass-thru path has an internal fixed gain of 2V/V (6 dB) amplifier that can drive 2 video lines with dc

coupling, traditional ac coupling, or SAG corrected ac coupling.

•

While disabled, the Monitor Pass-Thru path has a high output impedance (>500 k

Ω || 8 pF)

•

Power Up Control (PUC) allows the THS7327 to be fully disabled or have the Monitor Pass-Thru function

(with AC-Bias mode on all channels) enabled upon initial power-up.

•

•

H and V Sync paths have an externally adjustable Schmitt Trigger threshold

•

Disable mode which reduces quiescent current to as low as 0.1-

µA.

The THS7327 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 THS7327 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-Hz/60-Hz line

frequencies.

internal fixed gain of 2V/V (6 dB), 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 GND to 3.4 V. But due to the gain, the linear

output range limits the allowable linear input range to be from GND to at most 2.5 V.

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