Datasheet
7
LTC1290
1290fe
Sample-and-Hold Acquisition
Time vs Source Resistance
R
SOURCE
+ (Ω)
100
1
S & H AQUISITION TIME TO 0.02% (µs)
10
100
1k 10k
LTC1290 • TPC11
+
–
V
IN
R
SOURCE
+
V
REF
= 5V
V
CC
= 5V
T
A
= 25°C
0V TO 5V INPUT STEP
ACLK FREQUENCY (MHz)
0
SUPPLY CURRENT, I
CC
(µA)
1.00 2.00
3.00
4.00
1290 • TPC13
200
180
160
140
120
100
80
60
40
20
V
CC
= 5V
CMOS LEVELS
Supply Current (Power Shutdown)
vs ACLK
Supply Current (Power Shutdown)
vs Temperature
AMBIENT TEMPERATURE, T
A
(°C)
–50
SUPPLY CURRENT, I
CC
(µA)
10
9
8
7
6
5
4
3
2
1
0
–10
30
50 130
1290 • TPC12
–30 10
70
90
110
ACLK OFF DURING
POWER SHUTDOWN
Input Channel Leakage Current
vs Temperature
AMBIENT TEMPERATURE, T
A
(°C)
–50
0
INPUT CHANNEL LEAKAGE CURRENT (nA)
100
300
400
500
1000
700
–10
30
50 130
1290 • TPC14
200
800
900
600
–30 10
70 90
110
ON CHANNEL
OFF CHANNEL
GUARANTEED
Noise Error vs Reference Voltage
REFERENCE VOLTAGE, V
REF
(V)
0
0
PEAK-TO-PEAK NOISE ERROR (LSBs)
0.25
0.75
1.00
1.25
2
4
5
2.25
1290 • TPC15
0.50
13
1.50
1.75
2.00
LTC1290 NOISE 200µV
P-P
CH0 to CH7 (Pin 1 to Pin 8): Analog Inputs. The analog
inputs must be free of noise with respect to AGND.
COM (Pin 9): Common. The common pin defines the zero
reference point for all single-ended inputs. It must be free
of noise and is usually tied to the analog ground plane.
DGND (Pin 10): Digital Ground. This is the ground for the
internal logic. Tie to the ground plane.
AGND (Pin 11): Analog Ground. AGND should be tied
directly to the analog ground plane.
V
–
(Pin 12): Negative Supply. Tie V
–
to most negative
potential in the circuit. (Ground in single supply applica-
tions.)
REF
–
, REF
+
(Pins 13, 14): Reference Inputs. The refer-
ence inputs must be kept free of noise with respect to
AGND.
CS (Pin 15): Chip Select Input. A logic low on this input
enables data transfer.
D
OUT
(Pin 16): Digital Data Output. The A/D conversion
result is shifted out of this output.
Maximum Filter Resistor vs
Cycle Time
CYCLE TIME, t
CYC
(µs)
MAXIMUM R
FILTER
** (Ω)
10
100
1k
10k
10 1000 10000
1290 • TPC10
1.0
100
+
–
V
IN
C
FILTER
≥ 1µF
R
FILTER
** MAXIMUM R
FILTER
REPRESENTS THE FILTER RESISTOR
VALUE AT WHICH A 0.1LSB CHANGE IN FULL-SCALE
ERROR FROM ITS VALUE AT R
FILTER
= 0 IS FIRST DETECTED.
TYPICAL PERFOR A CE CHARACTERISTICS
UW
UU
U
PI FU CTIO S