AD1671

a FEATURES Conversion Time: 800 ns 1.25 MHz Throughput Rate Complete: On-Chip Sample-and-Hold Amplifier and Voltage Reference Low Power Dissipation: 570 mW No Missing Codes Guaranteed Signal-to-Noise Plus Distortion Ratio fIN = 100 kHz: 70 dB Pin Configurable Input Voltage Ranges Twos Complement or Offset Binary Output Data 28-Pin DIP and 28-Pin Surface Mount Package Out of Range Indicator AIN1 AIN2 Complete 12-Bit 1.25 MSPS Monolithic A/D Converter AD1671 FUNCTIONAL BLOCK DIAGRAM SHA OUT 5k UPO/BPO ENCODE VCC ACOM VEE VLOGIC DCOM S/H RANGE SELECT 5k X4 3-BIT FLASH DAC 3-BIT FLASH DAC COARSE 4-BIT FLASH 4 8-BIT LADDER MATRIX 3 REF IN REF OUT 2.5V REF 3 CORRECTION LOGIC 8 FINE 4-BIT FLASH 4 LATCHES AD1671 REF COM OTR MSB 12 BIT 1 –12 DAV PRODUCT DESCRIPTION The AD1671 is a monolithic 12-bit, 1.25 MSPS analog-todigital converter with an on-board, high performance sampleand-hold amplifier (SHA) and voltage reference. The AD1671 guarantees no missing codes over the full operating temperature range. The combination of a merged high speed bipolar/ CMOS process and a novel architecture results in a combination of speed and power consumption far superior to previously available hybrid implementations. Additionally, the greater reliability of monolithic construction offers improved system reliability and lower costs than hybrid designs. The fast settling input SHA is equally suited for both multiplexed systems that switch negative to positive full-scale voltage leve...