Datasheet LTC2484 (Analog Devices) - 10

LTC2484
Typical perForMance characTerisTics PSRR vs Frequency at VCC PSRR vs Frequency at VCC (2x Speed Mode) (2x Speed Mode)
0 0 VCC = 4.1V DC ±1.4V VCC = 4.1V DC ±0.7V REF+ = 2.5V REF+ = 2.5V –20 REF– = GND –20 REF– = GND IN+ = GND IN+ = GND –40 IN– = GND –40 IN– = GND fO = GND fO = GND –60 TA = 25°C –60 TA = 25°C –80 –80 REJECTION (dB) REJECTION (dB) –100 –100 –120 –120 –140 –140 0 20 40 60 80 100 120 140 160 180 200 220 30600 30650 30700 30750 30800 FREQUENCY AT VCC (Hz) FREQUENCY AT VCC (Hz) 2484 G39 2484 G40
pin FuncTions SDI (Pin 1):
Serial Data Input. This pin is used to select
CS (Pin 6):
Active LOW Chip Select. A LOW on this pin the line frequency rejection, input, temperature sensor enables the digital input/output and wakes up the ADC. and 2x speed mode. Data is shifted into the SDI pin on Following each conversion the ADC automatically enters the rising edge of serial clock (SCK). the sleep mode and remains in this low power state as
V
long as CS is HIGH. A LOW-to-HIGH transition on CS
CC (Pin 2):
Positive Supply Voltage. Bypass to GND (Pin 8) with a 1µF tantalum capacitor in parallel with 0.1µF during the Data Output transfer aborts the data transfer ceramic capacitor as close to the part as possible. and starts a new conversion.
V SDO (Pin 7):
Three-State Digital Output. During the data
REF (Pin 3):
Positive Reference Input. The voltage on output period, this pin is used as the serial data output. this pin can have any value between 0.1V and VCC. The When the chip select, CS, is HIGH (CS = V negative reference input is GND (Pin 8). CC), the SDO pin is in a high impedance state. During the conversion
IN+ (Pin 4), IN– (Pin 5):
Differential Analog Inputs. The and sleep periods, this pin is used as the conversion voltage on these pins can have any value between GND status output. The conversion status can be observed by – 0.3V and VCC + 0.3V. Within these limits the converter pulling CS LOW. bipolar input range (VIN = IN+ – IN–) extends from –0.5 •
GND (Pin 8):
Ground. Shared pin for analog ground, digital VREF to 0.5 • VREF . Outside this input range the converter ground and reference ground. Should be connected directly produces unique overrange and underrange output codes. to a ground plane through a minimum impedance. 2484ff 10 For more information www.linear.com/LTC2484 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics (Normal Speed) Pin Configuration Electrical Characteristics (2x Speed) Converter Characteristics Analog Input and Reference Digital Inputs and Digital Outputs Power Requirements Timing Characteristics Typical Performance Characteristics Pin Functions Functional Block Diagram Test Circuits Timing Diagrams Applications Information Package Description Revision History Typical Application Related Parts