Bt451 Datasheet (Brooktree) - Monolithic CMOS 256-Color Palette RAMDAC

Bt451, Monolithic CMOS 256-Color Palette RAMDAC

Pin Descriptions The Bt4978 is available in both 84-pin Plastic Leaded Chip Carrier (PLCC) and Ceramic PGA packages, as illustrated in Figure 1 and 2.

Pin descriptions are provided in Table 1.

Pin labels for the PGA package are given in Table 2.

Figure 1.

Bt457/8 84-Pin J-Lead Package 74 P2B 73 P2

Bt451 Bt457 125 MHz/135 MHz/165 MHz Monolithic CMOS 256 Color Palette RAMDAC Bt458 The Bt457 and Bt458 are pin and software-compatible RAMDACs designed specifically for high-performance, high-resolution color graphics.

The architecture enables the display of 1280 x 1024 bit-mapped color graphics (up to 8 bits per pixel plus up to 2 bits of overlay information), minimizing the use of costly ECL interfacing, as most of the high-speed (pixel clock) logic is contained on chip.

The multiple pixel

Bt451 Features

* include programmable blink rates, bit plane masking and blinking, color overlay capability, and a dual-port color palette RAM. Functional Block Diagram CLOCK

* CLOCK VAA GND FSADJUST VREF Distinguishing Features

* 165, 135, 125, 110, 80 MHz operation

* 4:1 or 5:1 input mux