Datasheet

6
LTC1412
TYPICAL PERFOR A CE CHARACTERISTICS
UW
RIPPLE FREQUENCY (Hz)
–80
AMPLITUDE OF POWER SUPPLY FEEDTHROUGH (dB)
–40
0
–100
–60
–20
10k 100k 1M 10M
1412 G08
–120
1k
V
SS
V
DD
DGND
Power Supply Feedthrough
vs Ripple Frequency
INPUT FREQUENCY (Hz)
20
COMMON MODE REJECTION (dB)
40
50
70
80
1k 100k 1M 10M
1412 G09
0
10k
60
30
10
Input Common Mode Rejection
vs Input Frequency
PIN FUNCTIONS
UUU
A
IN
+
(Pin 1): Positive Analog Input. ±2.5V input range
when A
IN
–
is grounded. ±2.5V differential if A
IN
–
is
driven.
A
IN
–
(Pin 2): Negative Analog Input. Can be grounded or
driven differentially with A
IN
+
.
V
REF
(Pin 3): 2.5V Reference Output.
REFCOMP (Pin 4): 4.06V Reference Bypass Pin.
Bypass to AGND with 10µF ceramic (or 10µF tantalum in
parallel with 0.1µF ceramic).
AGND (Pin 5): Analog Ground.
D11 to D4 (Pins 6 to 13): Three-State Data Outputs.
DGND (Pin 14): Digital Ground for Internal Logic.
D3 to D0 (Pins 15 to 18): Three-State Data Outputs.
DGND (Pin 19): Digital Ground for Internal Logic.
DV
DD
(Pin 20): 5V Positive Supply. Tie to Pin 28. Bypass
to AGND with 0.1µF ceramic.
OV
DD
(Pin 21): Positive Supply for the Output Drivers. Tie
to Pin 28 when driving 5V logic. Tie to 3V when driving
3V logic.
OGND (Pin 22): Digital Ground for the Output Drivers.
CONVST (Pin 23): Conversion Start Signal. This active low
signal starts a conversion on its falling edge.
CS (Pin 24): Chip Select. This input must be low for the
ADC to recognize the CONVST inputs.
BUSY (Pin 25): The BUSY Output Shows the Converter
Status. It is low when a conversion is in progress.
V
SS
(Pin 26): –5V Negative Supply. Bypass to AGND with
10µF ceramic (or 10µF tantalum in parallel with 0.1µF
ceramic).
DV
DD
(Pin 27): 5V Positive Supply. Tie to Pin 28.
AV
DD
(Pin 28): 5V Positive Supply. Bypass to AGND with
10µF ceramic (or 10µF tantalum in parallel with 0.1µF
ceramic).