Mobile device video buffer boosts viewers’ battery life
November 18, 2008
Mobile video devices including digital cameras, camera phones and personal media players can run longer with STMicroelectronics' new TSH122 video buffer IC. The company claims that its low operating current of 1.7mA draws the lowest standby current among its peers, at just 4nA typical and 500nA maximum.
Because lower power fits mobile needs, the TSH122 is a single-channel CVBS video buffer/filter with 6dB internal gain optimized for DC or AC coupling to a 75ohm cable. Operation from a single supply of 2.2V to 5V (tested at 2.5V and 3.3V) also makes it well-suited for battery-powered applications.
The TSF122 features a design that enables size and cost reductions. It includes a sixth-order reconstruction filter to attenuate DAC sampling aliases, thus taking up less board space. Internal gain-setting resistors reduce component count and footprint, and because SAG correction is implemented at the output, it can use a smaller coupling capacitor. This high level of integration in a compact 2.2mm x 2.4mm SC70-6 (SOT323-6) package maximizes PCB available to designers for adding extra features or reducing product size.
The performance advantages of the TSF122 show in video performance that includes differential gain of 0.5 percent, differential phase of 0.5 degrees and low group delay of 10ns. Attenuation at 27MHz is typically better than –36dB, and the amplifier achieves gain flatness beyond 5.4MHz. Rail-to-rail output capability also maximizes dynamic range for low-voltage operation.
For more information, visit www.st.com/stonline/products/literature/ds/14916.pdf.