LTC1419 UUUPI FU CTIO S+ ACONVST (Pin 23): Conversion Start Signal. This active IN (Pin 1): ±2.5V Positive Analog Input. low signal starts a conversion on its falling edge. – AIN (Pin 2): ±2.5V Negative Analog Input. CS (Pin 24): Chip Select. The input must be low for the VREF (Pin 3): 2.5V Reference Output. Bypass to AGND ADC to recognize CONVST and RD inputs. CS also sets with 1µF. the shutdown mode when SHDN goes low. CS and REFCOMP (Pin 4): 4.06V Reference Output. Bypass to SHDN low select the quick wake-up nap mode. CS high AGND with 10µF tantalum in parallel with 0.1µF or 10µF and SHDN low select sleep mode. ceramic. BUSY (Pin 25): The BUSY output shows the converter AGND (Pin 5): Analog Ground. status. It is low when a conversion is in progress. Data D13 to D6 (Pins 6 to 13): Three-State Data Outputs. The valid on the rising edge of BUSY. output format is 2’s complement. VSS (Pin 26): – 5V Negative Supply. Bypass to AGND DGND (Pin 14): Digital Ground for Internal Logic. Tie to with 10µF tantalum in parallel with 0.1µF or 10µF AGND. ceramic. D5 to D0 (Pins 15 to 20): Three-State Data Outputs. The DVDD (Pin 27): 5V Positive Supply. Short to Pin 28. output format is 2’s complement. AVDD (Pin 28): 5V Positive Supply. Bypass to AGND SHDN (Pin 21): Power Shutdown Input. Low selects with 10µF tantalum in parallel with 0.1µF or 10µF shutdown. Shutdown mode selected by CS. CS = 0 for ceramic. nap mode and CS = 1 for sleep mode. RD (Pin 22): Read Input. This enables the output drivers when CS is low. UUWFU CTIO AL BLOCK DIAGRA CSAMPLE +AIN AVDD CSAMPLE – AIN DVDD 2k ZEROING SWITCHES VREF 2.5V REF VSS + REF AMP 14-BIT CAPACITIVE DAC COMP – REFCOMP (4.096V) AGND 14 SUCCESSIVE APPROXIMATION • D13 OUTPUT LATCHES • REGISTER • D0 DGND INTERNAL CONTROL LOGIC CLOCK 1419 BD SHDN CONVST RD CS BUSY 1419fb 6