Mobile video devices including digital cameras, camera phones and personal media players can run longer using the new TSH122 video buffer IC from STMicroelectronics (NYSE: STM), one of the world leaders in analog ICs. The new device has a low operating current of 1.7mA and draws the lowest standby current among comparable devices, at just 4nA typical, 500nA maximum.
The TSH122 is a single-channel CVBS (Composite Video Baseband Signal) video buffer/filter with 6dB internal gain, optimized for DC or AC coupling to a 75-Ohm cable. The input can be directly connected to the video DAC, to drive composite video to an external device such as a TV display. Consistent with its low power consumption, operation from a single supply of 2.2Vto 5V (tested at 2.5V and 3.3V) also makes this device compatible with battery-powered applications.
By including a 6th-order reconstruction filter for attenuation of DAC sampling aliases, the TSH122 saves cost and board space. Internal gain-setting resistors further reduce component count and footprint. SAG correction is also implemented at the output, allowing the use of a smaller coupling capacitor. Achieving this high level of integration within the compact 2.2 x 2.4 mm SC70-6 (SOT323-6) package maximizes PCB space for designers to implement extra features or reduce end-product size.
Video-performance highlights for the TSH122 include differential gain of 0.5%, 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.
STMicroelectronics, www.st.com.
