LTC1401 UUUPIN FUNCTIONS VCC (Pin 1): Positive Supply, 3V. 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 60ns signals the ADC to wake up from Nap or Sleep mode. AIN (Pin 2): Analog Input. 0V to 2.048V. CONV (Pin 7): Conversion Start Signal. This active high VREF (Pin 3): 1.2V Reference Output. Bypass to GND signal starts a conversion on its rising edge. Keeping CLK (10µF tantalum in parallel with 0.1µF ceramic). low and pulsing CONV two/four times will put the ADC into GND (Pin 4): Ground. GND should be tied directly to an Nap/Sleep mode. analog ground plane. SHDN (Pin 8): Shutdown Input. Pull this pin Low to put the DOUT (Pin 5): The A/D conversion result is shifted out from ADC in Shutdown mode and save power (REFRDY will go this pin. Low). The device will draw 4.5µA in this mode. UUWFUNCTIONAL BLOCK DIAGRA C ZEROING SWITCH SAMPLE A V IN CC GND SHDN VREF 1.20V REF 12-BIT CAPACITIVE DAC COMP CLK CONTROL 12 LOGIC CONV SUCCESSIVE APPROXIMATION REGISTER/PARALLEL TO DOUT SERIAL CONVERTER LTC1401 • BD01 TEST CIRCUITS 3V 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 LTC1401 • TC01 1401fa 6