LTC1286/LTC1298

Micropower Sampling

12-Bit A/D Converters In

S0-8 Packages

FEATURES

■ 12-Bit Resolution

■ 8-Pin SOIC Plastic Package

■ Low Cost

■ Low Supply Current: 250µA Typ

■ Auto Shutdown to 1nA Typ.

■ Guaranteed ±3/4LSB Max DNL

■ Single Supply 5V to 9V Operation

■ On-Chip Sample-and-Hold

■ 60µs Conversion Time

■ Sampling Rates:

12.5 ksps (LTC1286)

11.1 ksps (LTC1298)

■ I/O Compatible with SPI, Microwire, etc.

■ Differential Inputs (LTC1286)

■ 2-Channel MUX (LTC1298)

■ 3V Versions Available: LTC1285/LTC1288

DESCRIPTION

The LTC1286/LTC1298 are micropower, 12-bit, successive approximation sampling A/D converters. They typically draw only 250µA of supply current when converting and automatically power down to a typical supply current of 1nA whenever they are not performing conversions. They are packaged in 8-pin SO packages and operate on 5V to 9V supplies. These 12-bit, switched-capacitor, successive approximation ADCs include sample-and-holds. The LTC1286 has a single differential analog input. The LTC1298 offers a software selectable 2-channel MUX. On-chip serial ports allow efficient data transfer to a wide range of microprocessors and microcontrollers over three wires. This, coupled with micropower consumption, makes remote location possible and facilitates transmitting data through isolation barriers. These circuits can be used in ratiometric applications or with an external reference. The high impedance analog inputs and the ability to operate with reduced spans (to 1.5V full scale) allow direct connection to sensors and transducers in many applications, eliminating the need for gain stages. 4.7µF 5V ANALOG INPUT –IN GND VCC CLK DOUT VREF LTC1286 MPU (e.g., 8051) P1.4 P1.3 P1.2 +IN 0V TO 5V RANGE LTC1286/98 • TA01 CS/SHDN 6 5 8 7 3 4 1 2 SERIAL DATA LINK

APPLICATIONS

■ Battery-Operated Systems

■ Remote Data Acquisition

■ Battery Monitoring

■ Handheld Terminal Interface

■ Temperature Measurement

■ Isolated Data Acquisition SAMPLE FREQUENCY (Hz) 0.1k 1 SUPPLY CURRENT (µA) 10 100 1000 1k 10k 100k LTC1286/98

■ TA02 TA = 25°C VCC = VREF = 5V fCLK = 200kHz D

PACKAGE/ORDER INFORMATION