Datasheet

LTC6990
5
6990fc
For more information www.linear.com/LTC6990
TYPICAL PERFORMANCE CHARACTERISTICS
V
SET
vs I
SET
V
SET
vs Supply Voltage V
SET
vs Temperature
Frequency Error vs R
SET
Frequency Error
vs Supply Voltage Frequency Error vs Temperature
V
+
= 3.3V, unless otherwise noted.
R
SET
(kΩ)
FREQUENCY ERROR (%)
6990 G01
4
3
2
1
–1
–2
–3
0
–4
10 100 1000
T
A
= 25°C
GUARANTEED MAX
OVER TEMPERATURE
GUARANTEED MIN
OVER TEMPERATURE
TYPICAL MAX
90% OF UNITS
TYPICAL MIN
SUPPLY VOLTAGE (V)
FREQUENCY ERROR (%)
6990 G02
0.5
0.4
0.3
0.1
0.2
–0.1
–0.2
–0.3
0
–0.5
–0.4
2 43 5 6
T
A
= 25°C
R
SET
= 800k
R
SET
= 200k
R
SET
= 50k
I
SET
(µA)
V
SET
(V)
6990 G04
1.003
1.002
1.001
1.000
0 2010 30 40
V
+
= 3.3V
T
A
= 25°C
SUPPLY VOLTAGE (V)
V
SET
(V)
6990 G05
1.003
1.002
1.001
1.000
2 43 5 6
R
SET
= 200k
T
A
= 25°C
TEMPERATURE (°C)
V
SET
(V)
6990 G06
1.020
1.005
1.000
1.010
1.015
0.995
0.990
0.985
0.980
–50 75500 25–25 100 125
R
SET
= 200k
3 TYPICAL PARTS
TEMPERATURE (°C)
ERROR (%)
6990 G03
1.5
0.5
1.0
0.0
–0.5
–1.0
–1.5
–50 –25 25 500 10075 125
V
+
= 3.3V
DIVCODE = 4
R
SET
= 50k
R
SET
= 267k
R
SET
= 800k
ELECTRICAL CHARACTERISTICS
Note 11: Long-term drift of silicon oscillators is primarily due to the
movement of ions and impurities within the silicon and is tested at 30°C
under otherwise nominal operating conditions. Long-term drift is specified
as ppm/√kHr due to the typically nonlinear nature of the drift. To calculate
drift for a set time period, translate that time into thousands of hours, take
the square root and multiply by the typical drift number. For instance, a
year is 8.77kHr and would yield a drift of 266ppm at 90ppm/√kHr. Drift
without power applied to the device may be approximated as 1/10th of the
drift with power, or 9ppm/√kHr for a 90ppm/√kHr device.