Datasheet LTC1854, LTC1855, LTC1856 (Analog Devices) - 9

LTC1854/LTC1855/LTC1856
pin FuncTions COM (Pin 1):
Common Input. This is the negative reference
AGND1 (Pin 14):
Analog Ground. point for all single-ended inputs. It must be free of noise
V
and is usually connected to the analog ground plane.
REF (Pin 15):
2.5V Reference Output. Bypass to analog ground with a 1µF tantalum capacitor.
CH0 (Pin 2):
Analog MUX Input.
REFCOMP (Pin 16):
Reference Buffer Output. Bypass to
CH1 (Pin 3):
Analog MUX Input. analog ground with a 10µF tantalum and a 0.1µF ceramic
CH2 (Pin 4):
Analog MUX Input. capacitor. Nominal output voltage is 4.096V.
CH3 (Pin 5):
Analog MUX Input.
AGND2 (Pin 17):
Analog Ground.
CH4 (Pin 6):
Analog MUX Input.
AGND3 (Pin 18):
Analog Ground. This is the substrate connection.
CH5 (Pin 7):
Analog MUX Input.
AV CH6 (Pin 8):
Analog MUX Input.
DD (Pin 19):
5V Analog Supply. Bypass to analog ground with a 0.1µF ceramic and a 10µF tantalum capacitor.
CH7 (Pin 9):
Analog MUX Input.
DVDD (Pin 20):
5V Digital Supply. Bypass to digital ground
MUXOUT+ (Pin 10):
Positive MUX Output. Output of the with a 0.1µF ceramic and a 10µF tantalum capacitor. analog multiplexer. Connect to ADC+ for normal opera-
OV
tion.
DD (Pin 21):
Positive Supply for the Digital Output Buffers (3V to 5V). Bypass to digital ground with a 0.1µF
MUXOUT– (Pin 11):
Negative MUX Output. Output of the ceramic and a 10µF tantalum capacitor. analog multiplexer. Connect to ADC– for normal opera-
BUSY (Pin 22):
Output shows converter status. It is low tion. when a conversion is in progress.
ADC+ (Pin 12):
Positive Analog Input to the Analog-to-
SDO (Pin 23):
Serial Data Output. Digital Converter.
ADC– (Pin 13):
Negative Analog Input to the Analog-to- Digital Converter. 1854565af 9 Document Outline Description Typical Application Absolute Maximum Ratings Pin Configuration Typical Performance Characteristics Pin Functions Applications Information Package Description Typical Application Related Parts