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NEW 140MHZ VIDEO PREAMP WITH ON-SCREEN DISPLAY (OSD) INPUTS COMPLETES FAMILY OF DEVICES FOR FULL RANGE OF CRT MONITORS

• For Full Range of Color CRT Monitors Up To 1600 X 1200
• Three Wideband Amplifiers at 85, 110 & 140MHz Include Blanking On-Chip
• Independent Drive Control For Each Channel For Color Balance
• TTL OSD Inputs, 50MHz Bandwidth
• All Video Controls Feature High-Input Impedance
• Spot Killer Blanks Outputs When Vcc Is Less Than 10.6V
• Output Stage Directly Drives Most Monolithic, Hybrid Or Discrete Drivers

June 23, 1996 - With the addition of a 140MHz, full-feature video preamplifier, National Semiconductor now offers a family of devices with on-screen display capability (OSD) for the full range of color CRT monitors. The LM1283N complements the two previous video preamplifiers with OSD inputs released this year by providing the ideal bandwidth for 17", 82KHz microprocessor controlled CRT monitors. The video section for the family features three matched video amplifiers which operate at 85MHz for the LM1281N, 110MHz for the LM1282N and 140MHz for the LM1283N. All devices feature on-chip blanking.

"Using microprocessor control and the screen itself for picture-in-picture digital readouts is an accurate, low-cost alternative to other solutions, including separate LED or LCD displays," said Harry Inia, monitors marketing manager. "With a family of OSD enabled video preamps, National is bringing the functionality and ease-of-use of this graphical interface to a full range of CRT monitors."

To permit wide control over individual color channels, the LM1281, LM1282 and LM1283N have extended drive control ranges of 12dB. This range allows the monitor to match the color of the display to the color generated in other output devices. All DC control inputs for the family offer high-input impedance and an operating range from 0V to 4V for easy interface to bus-controlled alignment systems. The three input channels each receive a video signal and an OSD signal at the input amplifier. Switching between OSD and video is controlled by a single input.

Both the OSD inputs and the video/OSD switch accept standard TTL signals. The OSD section features three TTL inputs and a DC contrast control. Inputs for the OSD are internally processed to match the OSD logic low level to the video black level. Each channel of the devices feature independent-drive controls for color balance. The OSD input tracks the video signal¹s drive controls. Contrast adjustments are independent, allowing the user to set the desired contrast of the OSD window without affecting the video portion of the display.

A spot killer is provided for CRT phosphor protection during power-down. The LM1281N, LM1282N and LM1283N also contain a blanking circuit which clamps the video output voltage during blanking to within 0.1V above ground. This feature provides blanking capability at the cathodes of the CRT.

Price and Availability:

The LM1281N, LM1282N and LM1283N are all currently available in 28-pin DIP packages rated for operation over the commercial temperature range of -20°C to +70°C. When purchased in quantities of 1,000, the LM1281N is priced at $2.50, the LM1282N is priced at $2.75 and the LM1283N is priced at $3.00 each.

National Semiconductor Corporation® provides Technologies For Moving and Shaping Information®. The company focuses on four strategic markets: communications, personal systems, industrial, and consumer. National Semiconductor is headquartered in Santa Clara, California, and has 20,000 employees worldwide. In fiscal 1995, the company reported sales of $2.4 billion.