LTC1286/LTC1298 Micropower Sampling 12-Bit A/D Converters In S0-8 Packages UFEATURESDESCRIPTION ■ 12-Bit Resolution The LTC1286/LTC1298 are micropower, 12-bit, succes- ■ 8-Pin SOIC Plastic Package sive approximation sampling A/D converters. They typi- ■ Low Cost cally draw only 250µA of supply current when converting ■ Low Supply Current: 250 µ A Typ. and automatically power down to a typical supply current ■ Auto Shutdown to 1nA Typ. of 1nA whenever they are not performing conversions. ■ Guaranteed ±3/4LSB Max DNL They are packaged in 8-pin SO packages and operate on ■ Single Supply 5V to 9V Operation 5V to 9V supplies. These 12-bit, switched-capacitor, suc- ■ On-Chip Sample-and-Hold cessive approximation ADCs include sample-and-holds. ■ 60µs Conversion Time The LTC1286 has a single differential analog input. The ■ Sampling Rates: LTC1298 offers a software selectable 2-channel MUX. 12.5 ksps (LTC1286) On-chip serial ports allow efficient data transfer to a wide 11.1 ksps (LTC1298) range of microprocessors and microcontrollers over three ■ I/O Compatible with SPI, Microwire, etc. wires. This, coupled with micropower consumption, makes ■ Differential Inputs (LTC1286) remote location possible and facilitates transmitting data ■ 2-Channel MUX (LTC1298) through isolation barriers. ■ 3V Versions Available: LTC1285/LTC1288 U These circuits can be used in ratiometric applications or APPLICATIONS with an external reference. The high impedance analog inputs and the ability to operate with reduced spans (to ■ Battery-Operated Systems 1.5V full scale) allow direct connection to sensors and ■ Remote Data Acquisition transducers in many applications, eliminating the need for ■ Battery Monitoring gain stages. ■ Handheld Terminal Interface ■ Temperature Measurement ■ Isolated Data Acquisition UTYPICAL APPLICATIONS N25 µ W, S0-8 Package, 12-Bit ADCSupply Current vs Sample RateSamples at 200Hz and Runs Off a 5V Supply 1000 TA = 25°C V 4.7µF 5V CC = VREF = 5V fCLK = 200kHz µA) 100 MPU (e.g., 8051) 1 8 V V REF CC P1.4 2 7 10 ANALOG INPUT +IN CLK LTC1286 P1.3 SUPPLY CURRENT ( 3 6 0V TO 5V RANGE –IN DOUT P1.2 4 5 SERIAL DATA LINK GND CS/SHDN LTC1286/98 • TA01 1 0.1k 1k 10k 100k SAMPLE FREQUENCY (Hz) LTC1286/98 • TA02 1