Datasheet
6
LTC1285/LTC1288
TYPICAL PERFORMANCE CHARACTERISTICS
U
W
INPUT FREQUENCY (Hz)
80
ATTENUATION (%)
60
40
50
20
0
90
70
30
10
1k 100k 1M 10M
LTC1285/86 • TPC15
100
10k
T
A
= 25°C
V
CC
= 2.7V
V
REF
= 2.5V
f
SMPL
= f
SMPL(MAX)
Attenuation vs Input Frequency
Power Supply Feedthrough
vs Ripple Frequency
Intermodulation Distortion
Maximum Clock Frequency
vs Supply Voltage
FREQUENCY (kHz)
0
–120
MAGNITUDE (dB)
–100
–80
–60
–40
1.0 2.0
3.0
4.0
LTC1285/88 • TPC17
–20
0
0.5 1.5
2.5
3.5
T
A
= 25°C
V
CC
= 2.7V
V
REF
= 2.5V
f1 = 2.05kHz
f2 = 3.05kHz
f
SMPL
= 7.5kHz
RIPPLE FREQUENCY (Hz)
–80
FEEDTHROUGH (dB)
–60
–40
–50
–20
0
–90
–70
–30
–10
1k 100k 1M 10M
LTC1285/86 • TPC18
–100
10k
T
A
= 25°C
V
CC
= 2.7V (V
RIPPLE
= 1mV)
V
REF
= 2.5V
f
CLK
= 120kHZ
SUPPLY VOLTAGE (V)
2.5
100
CLOCK FREQUENCY (kHz)
120
160
180
200
300
240
3.5
4.5
5.0
LTC1285/88 • TPC21
140
260
280
220
3.0
4.0
5.5
6.0
T
A
= 25°C
V
REF
= 2.5V
4096 Point FFT Plot
FREQUENCY (kHz)
0
–120
MAGNITUDE (dB)
–100
–80
–60
–40
1.0 2.0
3.0
4.0
LTC1285/88 • TPC16
–20
0
0.5 1.5
2.5
3.5
T
A
= 25°C
V
CC
= 2.7V
V
REF
= 2.5V
f
IN
= 3.05kHz
f
CLK
= 120kHz
f
SMPL
= 7.5kHz
Spurious-Free Dynamic Range
vs Input Frequency
INPUT FREQUENCY (kHz)
1
0
SPURIOUS-FREE DYNAMIC RANGE (dB)
20
40
60
80
10 100
LTC1285/88 • G13
100
10
30
50
70
90
T
A
= 25°C
V
CC
= 2.7V
V
REF
= 2.5V
f
SMPL
= f
SMPL(MAX)
Maximum Clock Frequency
vs Source Resistance
SOURCE RESISTANCE (kΩ)
0.1
0
CLOCK FREQUENCY (kHz)
40
80
120
160
110
LTC1285/88 • G19
200
20
60
100
140
180
T
A
= 25°C
V
CC
= 2.7V
V
REF
= 2.5V
–INPUT
+INPUTV
IN
R
SOURCE
–
S/(N + D) vs Input Level
INPUT LEVEL (dB)
–45
SIGNAL-TO-NOISE PLUS DISTORTION (dB)
40
50
60
–5
LTC1285/88 • TPC14
30
20
0
–35
–25
–15
–40 0
–30
–20
–10
10
80
70
T
A
= 25°C
V
CC
= 2.7V
V
REF
= 2.5V
f
IN
= 1kHz
f
SMPL
= f
SMPL(MAX)
Sample-and-Hold Acquisition
Time vs Source Resistance
SOURCE RESISTANCE (Ω)
1
100
S & H ACQUISITION TIME (ns)
1000
10000
100 100010 10000
LTC1285/88 • TPC20
T
A
= 25°C
V
CC
= 2.7V
V
REF
= 2.5V
–INPUT
+INPUTV
IN
R
SOURCE
+