LTC1292/LTC1297 Single Chip 12-Bit Data Acquisition Systems FEATURES DESCRIPTIO n Single Supply 5V Operation The LTC 1292/LTC1297 are data acquisition systems that n Power Shutdown After Each Conversion (LTC1297) contain a 12-bit, switched-capacitor successive approxi- n Built-In Sample-and-Hold mation A/D, a differential input, sample-and-hold on the n 60kHz Maximum Throughput Rate (LTC1292) (+) input, and serial I/O. When the LTC1297 is idle between n Direct 3-Wire Interface to Most MPU Serial Ports and conversions it automatically powers down reducing the All MPU Parallel Ports supply current to 5m A, typically. The LTC1292 is capable n Analog Inputs Common Mode to Supply Rails of digitizing signals at a 60kHz rate and with the devices excellent AC characteristics, it can be used for DSP appli- cations. All these features are packaged in an 8-pin DIP U TM KEY SPECIFICATIO S and are made possible using LTCMOS switched-capaci- tor technology. n Resolution: 12 Bits n Fast Conversion Time: 12m s Max Over Temp The serial I/O is designed to communicate without external n Low Supply Current: 6.0mA hardware to most MPU serial ports and all MPU parallel n Shutdown Supply Current: 5m A (LTC1297) I/O ports allowing data to be transmitted over three wires. Because of their accuracy, ease of use and small package size these devices are well suited for digitizing analog signals in remote applications where minimum number of interconnects and power consumption are important. , LTC and LT are registered trademarks of Linear Technology Corporation. LTCMOS is trademark of Linear Technology Corporation TYPICAL APPLICATIO Power Supply Current vs Sampling Frequency 12-Bit Differential Input Data Acquisition System 10000 V 5V DO CS CC + 1000 22F MC68HC11 TANTALUM DIFFERENTIAL m +IN + CLK SCK INPUTS 1N4148 COMMON MODE LTC1297 100 RANGE IN D MISO OUT 0V TO 5V * GND V LT1027 8V TO 40V 10 REF + 4.7F 1F TANTALUM 1 1 10 100 1k 10k 100k f (Hz) SAMPLE LTC1297 TA02 *FOR OVERVOLTAGE PROTECTION LIMIT THE INPUT CURRENT TO 15mA PER PIN OR CLAMP THE INPUTS TO V AND GND WITH 1N4148 DIODES. CC CONVERSION RESULTS ARE NOT VALID WHEN ANY INPUT IS OVERVOLTAGED (V < GND OR V > V ). SEE SECTION ON OVERVOLTAGE PROTECTION IN LTC1292/7 TA01 IN IN CC THE APPLICATIONS INFORMATION. 12927fb 1 AVERAGE I ( A) CC U ULTC1292/LTC1297 ABSOLUTEXAI U RATI GS PACKAGE/ORDER I FOR ATIO (Notes 1 and 2) Supply Voltage (V ) to GND.................................. 12V ORDER PART NUMBER CC TOP VIEW Voltage CS 1 8 V CC LTC1292BIN8 LTC1297BCN8 Analog and Reference +IN 2 7 CLK LTC1292CIN8 LTC1297CCN8 Inputs..................................... 0.3V to V + 0.3V CC IN 3 6 D LTC1292DIN8 LTC1297DCN8 OUT Digital Inputs........................................ 0.3V to 12V GND 4 5 V LTC1292BCN8 REF Digital Outputs .......................... 0.3V to V + 0.3V CC LTC1292CCN8 Power Dissipation.............................................. 500mW N8 PACKAGE LTC1292DCN8 8-LEAD PLASTIC DIP Operating Temperature Range T = 100 C, q =130 C/W (N8) JMAX JA LTC1292/LTC1297BC, LTC1292/LTC1297CC, LTC1292/LTC1297DC ............................ 0 C to 70 C LTC1292BCJ8 LTC1297BCJ8 LTC1292BI, LTC1292CI, J8 PACKAGE LTC1292CCJ8 LTC1297CCJ8 8-LEAD CERAMIC DIP LTC1292DI ......................................... 40 C to 85 C T = 150 C, q =100 C/W (J8) LTC1292DCJ8 LTC1297DCJ8 JMAX JA Storage Temperature Range ................. 65 C to 150 C OBSOLETE PACKAGE Lead Temperature (Soldering, 10 sec.)................ 300 C Consider the N8 Package for Alternate Source Consult LTC Marketing for parts specified with wider operating temperature ranges. UU W The l denotes the specifications CO VERTER A D ULTIPLEXER CHARACTERISTICS which apply over the full operating temperature range, otherwise specifications are at T = 25 C. (Note 3) A LTC1292B LTC1292C LTC1292D LTC1297B LTC1297C LTC1297D PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX MIN TYP MAX UNITS Offset Error (Note 4) l 3.0 3.0 3.0 LSB Linearity Error (INL) (Note 4 & 5) l 0.5 0.5 0.75 LSB Gain Error (Note 4) l 0.5 1.0 4.0 LSB Minimum Resolution for Which No 12 12 12 Bits Missing Codes are Guaranteed Analog and REF Input Range (Note 7) l 0.05V to V + 0.05V V CC On Channel Leakage Current On Channel = 5V l 1 1 1 m A (Note 8) Off Channel = 0V On Channel = 0V l 1 1 1 m A Off Channel = 5V Off Channel Lekage Current On Channel = 5V l 1 1 1 m A (Note 8) Off Channel = 0V On Channel = 0V l 1 1 1 m A Off Channel = 5V 12927fb 2 U WU U W W W