Datasheet

LTC2440
14
2440fe
For more information www.linear.com/LTC2440
APPLICATIONS INFORMATION
Figure 4. SDI Speed/Resolution Programming
MSB
BIT 28 BIT 27 BIT 26 BIT 25 BIT 1 BIT 0
LSB
Hi-Z
2440 F04
SIG
BIT 29
“0”
BIT 30
EOC
Hi-Z
CS
SCK
SDI
SDO
BUSY
BIT 31
*OSR4 BIT MUST BE AT FIRST SCK RISING EDGE DURING SERIAL DATA OUT CYCLE
OSR4* OSR3 OSR2 OSR1 OSR0
Table 3. SDI Speed/Resolution Programming
OSR4 OSR3 OSR2 OSR1 OSR0
RMS
NOISE ENOB OSR
X 0 0 0 1 23µV 17 64
X 0 0 1 0 3.5µV 20 128
0 0 0 0 0 2µV 21.3 256*
X 0 0 1 1 2µV 21.3 256
X 0 1 0 0 1.4µV 21.8 512
X 0 1 0 1 1µV 22.4 1024
X 0 1 1 0 750nV 22.9 2048
X 0 1 1 1 510nV 23.4 4096
X 1 0 0 0 375nV 24 8192
X 1 0 0 1 250nV 24.4 16384
X 1 1 1 1 200nV 24.6 32768**
**Address allows tying SDI HIGH *Additional address to allow tying SDI LOW
↑
↑
Table 4. LTC2440 Interface Timing Modes
Configuration
SCK
Source
Conversion
Cycle
Control
Data
Output
Control
Connection
and
Waveforms
External SCK, Single Cycle Conversion External CS and SCK CS
and SCK Figures 5, 6
External SCK, 2-Wire I/O External SCK SCK Figure 7
Internal SCK, Single Cycle Conversion Internal CS CS Figures 8, 9
Internal SCK, 2-Wire I/O, Continuous Conversion Internal Continuous Internal Figure 10
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