LTC2391-16 PIN FUNCTIONSBUSY (Pin 29): Busy Output. A low-to-high transition oc- VCM (Pin 36): Common Mode Analog Output. Typically curs when a conversion is started. It stays high until the the output voltage is 2.048V. Bypass to GND with a 10μF conversion is complete. The falling edge of BUSY can be capacitor. used as the data-ready clock signal. REFOUT (Pin 37): Internal Reference Output. Nominal RD (Pin 30): Read Data Input. When CS and RD are both output voltage is 4.096V. Connect this pin to REFIN if us- low, the parallel and serial output bus is enabled. ing the internal reference. If an external reference is used CS connect REFOUT to ground. (Pin 31): Chip Select. When CS and RD are both low, the parallel and serial output bus is enabled. CS is also REFIN (Pin 38): Reference Input. An external reference used to gate the external shift clock. can be applied to REFIN if a more accurate reference is required. If an external reference is used tie REFOUT to RESET (Pin 32): Reset Input. When high the LTC2391-16 ground. is reset, and if this occurs during a conversion, the con- version is halted and the data bus is put into Hi-Z mode. REFSENSE (Pin 39): Reference Input Sense. Leave REFSENSE open when using the internal reference. If PD (Pin 33): Power-Down Input. When high, the an external reference is used connect REFSENSE to the LTC2391-16 is powered down and subsequent conversion ground pin of the external reference. requests are ignored. Before entering power shutdown, the digital output data should be read. IN–, IN+ (Pin 42, Pin 43): Differential Analog Inputs. CNVST IN+ – (IN–) can range up to ±V (Pin 34): Conversion Start Input. A falling edge REF . on CNVST puts the internal sample-and-hold into the hold mode and starts a conversion. CNVST is independent of CS. 239116fa 9