STMicroelectronics has announced the introduction of two new 300MHz amplifiers designed to drive very high-definition signals on 75-ohm video lines in high-end industrial and medical imaging systems, and in HDTV-enabled set-top boxes and DVD players.

The cost-effective TSH340 and TSH341 video amplifiers feature operation on a single 3V to 5V single power supply, with the capability to drive the video signal very close to zero volts.

The TSH340 is a buffer with internal gain, providing savings both on board space and in the number of components; the gain is set at 6dB to allow the right level of video signal while maintaining good line matching. The TSH341 is an op-amp that uses the same voltage feedback architecture as the TSH340, but allows the gain to be set externally. Both use a very high-speed 0.25-micron complementary manufacturing technology to achieve up to 300MHz bandwidth for only 9.8mA quiescent current.

High slew rates, low distortion and a gain flatness of 65MHz, combined with a low input-voltage noise of 7nV/sqrtHz, make the TSH340 and TSH341 devices an excellent choice to drive DAC outputs on 75-ohm video lines. The amplifiers are input/output negative rail, which allows them to drive the signal to within 60mV of ground – guaranteed by production testing – while operating on a single 5V supply, and enables the video signal to be driven directly from the DAC output without any transition capacitance.

The use of a single power supply, eliminating the need for the negative supply that is usually required, reduces the complexity of applications using the devices and so reduces costs. These are essential and easy-to-use components for high performance video equipment demanding wide bandwidth and high signal purity. The amplifiers are specified for both 150-ohm and 100-ohm loads, and are supplied in the tiny SOT23-5 and SO8 plastic packages.

The TSH340 and TSH341 video amplifiers are supported by an evaluation board kit, optimized for high-speed operational amplifiers, which includes a CD-ROM containing datasheets, application notes, articles and a user manual.