Datasheet

10
LT1394
TEMPERATURE (°C)
0
0
–10
–20
–30
–40
–50
–60
–70
30 50
1394 F06
10 20
40 60 70
FREQUENCY DEVIATION (ppm)
COMPENSATED
≈ 0.05ppm/°C
UNCOMPENSATED
(VARACTOR CORRECTION
DISABLED) –1ppm/°C
Figure 6. Figure 5’s Compensated vs Uncompensated
Temperature Dependence. First Order Compensation
Reduces Oscillator Drift to 0.05ppm/°C
–
+
A2
1/2 LT1126
–
+
5V
5V
200pF
OUTPUT
1394 F07
+INPUT
–INPUT
–5V
–5V
1µF
1µF
200pF
2k
1k
1k
2k
10k
10k
200Ω
–
+
A1
LM733
A = 100
–
+
LT1394
A3
1/2 LT1126
–
+
Figure 7. Parallel Preamplified Paths Allow 18ns Comparator
Response to 500µV Overdrive
APPLICATIONS INFORMATION
WUU
U
Figure 5. Temperature-Compensated 10MHz Crystal Oscillator.
Temperature-Dependent Varactor Bias Reduces Drift by 20:1
1394 F05
–
+
LT1394
–
+
A1
LT1077
50k
5V
10M
390Ω
0.01µF
1µF
0.068µF
10mV/°C
10MHz
0.05ppm/°C
XTAL AT-CUT, 35° 25′ ANGLE
* 1% FILM RESISTOR
LM134
5V
FREQ SET
LT1004-1.2
BAT-85
10MHz
1M*
1M*
5.8M*
MV-209
VARACTOR
DIODE
2M
2k
0.01µF
1µF
2M
2k
4.7k
100k
1M
470k*
10k*
+
226Ω*