Datasheet

ADS5421
5
SBAS237E
www.ti.com
10 Clock Cycles
Data Invalid
t
D
t
DV
t
L
t
H
t
CONV
N 10 N 9N 8N 7N 6N 5N 4N 3N 2N 1N
Data Out
Data Valid Output
Clock
Analog In
N
t
2
N + 1
N + 2
N + 3
N + 4
N + 5
N + 6
N + 7
N + 8
N + 9
N + 10
t
1
TIMING DIAGRAM
REFERENCE AND FULL-SCALE RANGE SELECT TABLE
DESIRED FULL-SCALE RANGE SEL1 SEL2 INTERNAL V
REF
4V
PP
GND GND 2V
3V
PP
GND +V
SA
1.5V
NOTE: For external reference operation, tie V
REF
to +V
SA
. The full-scale range will be 2x the reference value. For example, selecting a 2V external reference
will set the full-scale values of 1.5V to 3.5V for both IN and IN inputs.
SYMBOL DESCRIPTION MIN TYP MAX UNITS
t
CONV
Convert Clock Period 25 1µsns
t
L
Clock Pulse LOW 11.5 t
CONV
/2 ns
t
H
Clock Pulse HIGH 11.5 t
CONV
/2 ns
t
D
Aperture Delay 3 ns
t
1
Data Hold Time, C
L
= 0pF 3.9 7.2 ns
t
2
New Data Delay Time, C
L
= 15pF max 12.7 ns
t
DV
Data Valid Output, C
L
= 15pF 4.4 ns