LTC1594L/LTC1598L 4- and 8-Channel, 3V Micropower Sampling 12-Bit Serial I/O A/D Converters UFEATURESDESCRIPTIO ■ 12-Bit Resolution on 3V Supply The LTC®1594L/LTC1598L are 3V micropower, 12-bit ■ Low Supply Current: 160 µ A Typ sampling A/D converters that feature 4- and 8-channel ■ Auto Shutdown to 1nA multiplexers, respectively. They typically draw only 160µA ■ Guaranteed ± 3/4LSB Max DNL of supply current when converting and automatically ■ Guaranteed 2.7V Operation power down to a typical supply current of 1nA between (5V Versions Available: LTC1594/LTC1598) conversions. The LTC1594L is available in a 16-pin SO ■ Multiplexer: 4-Channel MUX (LTC1594L) package and the LTC1598L is packaged in a 24-pin 8-Channel MUX (LTC1598L) SSOP. Both operate on a 3V supply. The 12-bit, switched- ■ Separate MUX Output and ADC Input Pins capacitor, successive approximation ADCs include a ■ MUX and ADC May Be Controlled Separately sample-and-hold. ■ Sampling Rate: 10.5ksps On-chip serial ports allow efficient data transfer to a wide ■ I/O Compatible with QSPI, SPI and MICROWIRETM, etc. range of microprocessors and microcontrollers over three ■ Small Package: 16-Pin Narrow SO (LTC1594L) or four wires. This, coupled with micropower consump- 24-Pin SSOP (LTC1598L) U tion, makes remote location possible and facilitates trans- APPLICATIO S mitting data through isolation barriers. The circuit can be used in ratiometric applications or with ■ Pen Screen Digitizing an external reference. The high impedance analog inputs ■ Battery-Operated Systems and the ability to operate with reduced spans (to 1.5V full ■ Remote Data Acquisition scale) allow direct connection to sensors and transducers ■ Isolated Data Acquisition in many applications, eliminating the need for gain stages. ■ Battery Monitoring , LTC and LT are registered trademarks of Linear Technology Corporation. ■ Temperature Measurement MICROWIRE is a trademark of National Semiconductor Corporation. UTYPICAL APPLICATION12 µ W, 8-Channel, 12-Bit ADC Samples at 200Hz and Runs Off a 3V Supply OPTIONAL ADC FILTER Supply Current vs Sample Rate 1k 3V 1µF 1000 TA = 25°C VCC = 2.7V 18 17 16 15, 19 1µF VREF = 2.5V MUXOUT ADCIN VREF VCC fCLK = 200kHz 20 CH0 SERIAL DATA LINK µA) 100 21 MICROWIRE AND CH1 10 CSADC SPI COMPATABLE 22 CH2 6 ANALOG CSMUX 23 CH3 12-BIT 5, 14 INPUTS 8-CHANNEL CLK + SAMPLING 0V TO 3V 24 CH4 MUX 7 MPU ADC D 10 RANGE IN 1 CH5 11 SUPPLY CURRENT ( D – OUT 2 CH6 3 12 CH7 LTC1598L NC 8 13 COM NC 1 GND 0.1 1 10 100 4, 9 1594L/98L TA01 SAMPLE FREQUENCY (kHz) 1594L/98L TA02 15948lfb 1
