LTC1400 UUUPI FU CTIO SVCC (Pin 1): Positive Supply, 5V. Bypass to GND (10μF CLK (Pin 6): Clock. This clock synchronizes the serial data tantalum in parallel with 0.1μF ceramic). transfer. A minimum CLK pulse of 50ns will cause the ADC A to wake up from Nap or Sleep mode. IN (Pin 2): Analog Input. 0V to 4.096V (Unipolar), ±2.048V (Bipolar). CONV (Pin 7): Conversion Start Signal. This active high V signal starts a conversion on its rising edge. Keeping CLK REF (Pin 3): 2.42V Reference Output. Bypass to GND (10 low and pulsing CONV two/four times will put the ADC μF tantalum in parallel with 0.1μF ceramic). into Nap/Sleep mode. GND (Pin 4): Ground. GND should be tied directly to an analog ground plane. VSS (Pin 8): Negative Supply. –5V for bipolar operation. Bypass to GND with 0.1μF ceramic. VSS should be tied to DOUT (Pin 5): The A/D conversion result is shifted out GND for unipolar operation. from this pin. UUWFU CTIO AL BLOCK DIAGRA CSAMPLE ZEROING SWITCH A V IN CC GND VSS VREF 2.42V REF 12-BIT CAPACITIVE DAC COMP CLK CONTROL 12 LOGIC CONV SUCCESSIVE APPROXIMATION REGISTER/PARALLEL TO DOUT SERIAL CONVERTER 1400 BD01 TEST CIRCUITS 5V 3k DOUT DOUT 3k CLOAD CLOAD Hi-Z TO VOH Hi-Z TO VOL VOL TO VOH VOH TO VOL VOH TO Hi-Z VOL TO Hi-Z 1400 TC01 1400fa 6