TDC1044AN9C

www.fairchildsemi.com TDC1044A Monolithic Video A/D Converter 4-Bit, 25 Msps Features 4-bit resolution 1/4 LSB non-linearity Sample-and-hold circuit not required 25 Msps conversion rate Selectable output format 16-lead DIP and 20-lead PLCC packages Description The TDC1044A is a 25 Msps (Megasample per second) fullparallel analog-to-digital converter, capable of converting an analog signal with full-power frequency components up to 12.5 MHz into 4-bit digital words. Use of a sample-and-hold circuit is not necessary for operation of the TDC1044A. All digital inputs and outputs are TTL compatible. The TDC1044A consists of 15 latching comparators, encoding logic, and an output register. A single convert signal controls the conversion operation. Output formats are true/inverted binary or true/inverted offset two’s complement codes. Applications Digital communications Video special effects Radar data conversion Medical imaging Block Diagram NMINV NLINV CONV VIN RT R1 R 2 R 1 R RM R 8 15 TO 4 DECODER LATCH 4 D1–D4 R 14 65-1044A-01 R 15 R/2 RB REFERENCE RESISTOR CHAIN DIFFERENTIAL COMPARATORS (15) Rev. 1.1.2 TDC1044A PRODUCT SPECIFICATION Functional Description General Information The TDC1044A has three functional sections: a comparator array, encoding logic, and an output register. The comparator array compares the input signal with 15 reference voltages to produce an N-of-15 thermometer code. All the comparators referred to voltages more positive tha...