Datasheet LTC1857, LTC1858, LTC1859 (Analog Devices) - 7

LTC1857/LTC1858/LTC1859
TYPICAL PERFORMANCE CHARACTERISTICS LTC1859 Power Supply Feedthrough vs Ripple Frequency Supply Current vs Supply Voltage Supply Current vs Temperature
–10 9.0 9.0 fSAMPLE = 100kHz fSAMPLE = 100kHz fSAMPLE = 100kHz V –20 RIPPLE = 60mV 8.5 8.5 –30 –40 8.0 8.0 –50 –60 SUPPLY CURRENT (mA) 7.5 7.5 POWER SUPPLY FEEDTHROUGH (dB) –70 POSITIVE SUPPLY CURRENT (mA) –80 7.0 7.0 100 1k 10k 100k 1M 4.5 4.75 5 5.25 5.5 –50 –25 0 25 50 75 100 RIPPLE FREQUENCY (Hz) SUPPLY VOLTAGE (V) TEMPERATURE (°C) 1859 G10 1859 G11 1859 G12
PIN FUNCTIONS COM (Pin 1):
Common Input. This is the reference point
AGND1 (Pin 14):
Analog Ground. for all single-ended inputs. It must be free of noise and is
V
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 ana- with a 0.1µF ceramic and a 10µF tantalum capacitor. log multiplexer. Connect to ADC+ for normal operation.
OVDD (Pin 21):
Positive Supply for the Digital Output
MUXOUT– (Pin 11):
Negative MUX Output. Output of the ana- Buffers (3V to 5V). Bypass to digital ground with a 0.1µF log multiplexer. Connect to ADC– for normal operation. ceramic and a 10µF tantalum capacitor.
ADC+ (Pin 12):
Positive Analog Input to the Analog-to-
BUSY (Pin 22):
Output shows converter status. It is low Digital Converter. when a conversion is in progress.
ADC– (Pin 13):
Negative Analog Input to the Analog-to-
SDO (Pin 23):
Serial Data Output. Digital Converter. 185789fb For more information www.linear.com/LTC1857 7 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Converter and Multplexer Characteristics Analog Input Dynamic Accuracy Internal Reference Characteristics Digital Inputs and Digital Outputs Power Requirements Timing Characteristics Typical Performance Characteristics Pin Functions Functional Block Diagram Test Circuits Timing Diagrams Operation Applications Information Package Description Revision History Typical Application Related Parts