LTC1392 WUTYPICAL PERFORMANCE CHARACTERISTICSThermal Response in Stirred Oil BathThermal Response in Still AirSupply Current vs Sample Rate 70 70 1000 65 VCC = 5V VCC = 5V CS LOW BETWEEN SAMPLES 65 60 60 100 55 µA) °C) 55 °C) CS HIGH BETWEEN 50 50 SAMPLES 45 45 10 40 40 N8 TEMPERATURE ( 35 TEMPERATURE ( 35 S8 N8 SUPPLY CURRENT ( 1 30 30 VCC = 5V S8 f 25 CLK = 250kHz 25 TA = 25°C 20 0.1 20 0 5 10 15 20 25 30 0 50 250 300 0.1 1 10 100 1k 10k 100k 100 150 200 TIME (SEC) SAMPLE FREQUENCY (Hz) TIME (SEC) 1392 G09 1392 G07 1392 G08 UUUPIN FUNCTIONSDIN (Pin 1): Digital Input. The A/D configuration word is GND (Pin 5): Ground Pin. GND should be tied directly to shifted into this input. an analog ground plane. DOUT (Pin 2): Digital Output. The A/D result is shifted out +VIN (Pin 6): Positive Analog Differential Input. The pin of this output. can be used as a single-ended input by grounding – VIN. CLK (Pin 3): Shift Clock. This clock synchronizes the serial – VIN (Pin 7): Negative Analog Differential Input. The input data. must be free from noise. CS (Pin 4): Chip Select Input. A logic low on this input VCC (Pin8): Positive Supply. This supply must be kept free enables the LTC1392. from noise and ripple by bypassing directly to the ground plane. WBLOCK DIAGRAM 3 CLK VREF = 2.42V INPUT 1 VREF = 1V D SHIFT BANDGAP IN REGISTER VREF = 0.5V 2 D SERIAL OUT PORT 10-BIT CAPACITIVE DAC 10 TEMPERATURE BITS + SENSOR GND – COMP 10-BIT ANALOG VCC + SAR INPUT VREF – MUX 6 C +V SAMPLE IN + 7 –VIN – CONTROL 4 CS 8 5 AND TIMING V GND LTC1392 • BD CC 5