6
LTC1279
TYPICAL PERFORMANCE CHARACTERISTICS
U
W
INPUT FREQUENCY (Hz)
10k
SIGNAL/(NOISE
+
DISTORTION)
(dB)
80
70
60
50
40
30
20
10
0
100k
1M
10M
1279 G04
fSAMPLE = 600kHz
VIN = –60dB
VIN = –20dB
VIN = 0dB
S/(N + D) vs Input Frequency
and Amplitude
INPUT FREQUENCY (Hz)
10k
AMPLITUDE
(dB
BELOW
THE
FUNDAMENTAL)
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
100k
1M
1279 G06
2M
THD
2ND HARMONIC
3RD HARMONIC
fSAMPLE = 600kHz
Distortion vs Input Frequency
Peak Harmonic or Spurious
Noise vs Input Frequency
INPUT FREQUENCY (Hz)
10k
SPURIOUS-FREE
DYNAMIC
RANGE
(dB)
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
100k
1M
1279 G07
2M
fSAMPLE = 600kHz
INPUT FREQUENCY (Hz)
10k
SIGNAL-TO-NOISE
RATIO
(dB)
80
70
60
50
40
30
20
10
0
100k
1M
10M
1279 G05
fSAMPLE = 600kHz
Signal-to-Noise Ratio (Without
Harmonics) vs Input Frequency
Intermodulation Distortion Plot
SOURCE RESISTANCE (
)
10
ACQUISITION
TIME
(ns)
2500
2000
1500
1000
500
0
100
1k
10k
1279 G09
TA = 25°C
Acquisition Time vs
Source Impedance
Supply Current vs Temperature
TEMPERATURE (
°C)
–55
SUPPLY
CURRENT,
I
DD
(mA)
15
12
9
6
3
0
50
75
1279 G10
–25
25
100
125
fSAMPLE = 600kHz
RIPPLE FREQUENCY (Hz)
1k
AMPLITUDE
OF
POWER
SUPPLY
FEEDTHROUGH
(dB)
0
–20
–40
–60
–80
–100
–120
10k
100k
1M
1279 G11
fSAMPLE = 600kHz
VSS(VRIPPLE = 10mV)
AVDD(VRIPPLE = 1mV)
DGND(VRIPPLE = 100mV)
Power Supply Feedthrough vs
Ripple Frequency
LOAD CURRENT (mA)
–8
REFERENCE
VOLTAGE
(V)
2.435
2.430
2.425
2.420
2.415
2.410
2.405
2.400
2.395
2.390
–6
–4 –3
1
2
1279 G12
–7
–5
–2 –1
0
Reference Voltage vs
Load Current
FREQUENCY (kHz)
0
AMPLITUDE
(dB)
50
100
150
200
1279 G08
250
300
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
–120
fSAMPLE = 600kHz
fa = 94.189kHz
fb = 97.705kHz
(fb – fa)
(2fa – fb)
(2fa)
(2fb)
(3fa)
(2fb – fa)
(fa) (fb)
(fa + fb) (2fa + fb)
(fa + 2fb)
(3fb)