Title :
A high-performance CMOS 70-MHz palette/DAC
Author :
Letham, Lawrence ; Ahuja, Bhupendra K. ; Quader, Khandker N. ; Mayer, Ronald J. ; Larsen, Robert E. ; Canepa, George R.
fDate :
12/1/1987 12:00:00 AM
Abstract :
A VLSI circuit has been developed that combines dual-ported RAMs and three high-speed 8-b digital-to-analog converters (DACs). It is known as a palette/DAC. A 6-2 segmented DAC architecture improves differential linearity and monotonicity. The current-source cell uses a cascode device to improve the DAC´s linearity. A reference current, set by an on-chip bandgap reference voltage generator, and its associated distribution scheme eliminate the negative effects of threshold mismatches between current source cells, supply line resistance, and noise. The maximum conversion rate is 70 MHz with typical DC differential nonlinearity of 0.48 LSB (least significant bit). The 253-mil/SUP 2/ is designed on a double-metal CMOS process and consumes 1.2 W of power.
Keywords :
CMOS integrated circuits; Computer graphic equipment; Digital integrated circuits; Digital-analogue conversion; Random-access storage; VLSI; computer graphic equipment; digital integrated circuits; digital-analogue conversion; random-access storage; Buffer storage; Circuits; Color; Current supplies; Graphics; Linearity; Monitoring; Read-write memory; Switches; Very large scale integration;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.1987.1052853
