Datasheet LTC2387-18 (Analog Devices) - 8

LTC2387-18
Typical perForMance characTerisTics TA = 25°C, VDD = 5V, VDDL = 2.5V, OVDD = 2.5V, REFIN = 2.048V, fSMPL = 15Msps, unless otherwise noted. Analog Input Current Internal Reference Output Supply Current vs Sample Rate vs Differential Input V Differential Input V oltage oltage vs Temperature
35 1.00 2.050 fSMPL = 15Msps THREE TYPICAL UNITS 30 0.75 IN– 0.50 25 2.049 0.25 20 IVDDL 0 IVDD 15 Y CURRENT (mA) IOVDD –0.25 2.048 10 SUPPL –0.50 REFERENCE OUTPUT (V) ANALOG INPUT CURRENT (mA) 5 IN+ –0.75 0 –1.00 2.047 0 5 10 15 –4.096 –2.048 0 2.048 4.096 –40 –20 0 20 40 60 80 SAMPLE RATE (Msps) DIFFERENTIAL INPUT (V) TEMPERATURE (°C) 238718 G18 238718 G19 238718 G20
pin FuncTions GND (Pins 1, 4, 10, 21, 26, 29 ):
Ground. Connect to a
REFBUF (Pins 7, 8):
Internal Reference Buffer Output. solid ground plane in the PCB underneath the ADC. The output voltage of the internal 2× gain reference buffer,
IN+, IN– (Pins 2, 3):
Positive and Negative Differential nominally 4.096V, is provided on this pin. The two pins Analog Inputs. The inputs must be driven differentially should be shorted together and bypassed to REFGND with and 180° out of phase, with a common mode voltage of a 10µF (X7R, 0805 size) ceramic capacitor. If the internal 2.048V. The differential input range is ±4.096V (each input buffer is not required, tie REFIN to GND to power down the pin swings from 0V to 4.096V.) buffer and connect an external 4.096V reference to REFBUF.
REFGND (Pins 5, 6):
Reference Ground. The two pins
REFIN (Pin 9):
Internal Reference Output/Reference Buffer should be shorted together and connected to the refer- Input. The output voltage of the internal reference, nomi- ence bypass capacitor with a short, wide trace. In ad- nally 2.048V, is output on this pin. An external reference dition, connect the pins to the exposed pad (Pin 33). A can be applied to REFIN if a more accurate reference is suggested layout is shown in the ADC Reference section required. For increased filtering of reference noise, bypass of the data sheet. this pin to GND using a 0.1µF or larger ceramic capacitor. If the internal reference buffer is not used, tie REFIN to GND to power down the buffer and connect an external buffered reference to REFBUF. 238718fa 8 For more information www.linear.com/LTC2387-18 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Converter Characteristics Dynamic Accuracy Internal Reference Characteristics Reference Buffer Characteristics Digital Inputs and Digital Outputs Power Requirements ADC Timing Characteristics Typical Performance Characteristics Pin Functions Functional Block Diagram Timing Diagram Applications Information Package Description Typical Application Related Parts