Datasheet
LTC6908-1/LTC6908-2
3
690812fa
The ● denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. Test conditions are V
+
= 2.7V to 5.5V, R
L
= 5k, C
L
= 5pF unless otherwise
noted. The modulation is turned off (MOD is connected to OUT2) unless otherwise specifi ed. R
SET
is defi ned as the resistor connected
from the SET pin to the V
+
pin.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Δf
OUT
Frequency Accuracy (Note 4) V
+
= 2.7V 250kHz ≤ f
OUT
≤ 5MHz
250kHz ≤ f
OUT
≤ 5MHz
50kHz ≤ f
OUT
< 250kHz
●
●
±0.5
±2
±2.5
±1.5
±2.5
±3.5
%
%
%
V
+
= 5V 250kHz ≤ f
OUT
≤ 5MHz
250kHz ≤ f
OUT
≤ 5MHz
50kHz ≤ f
OUT
< 250kHz
5MHz < f
OUT
≤ 10MHz
●
●
●
±1
±2.5
±3
±3.5
±2
±3
±4
±4.5
%
%
%
%
R
SET
Frequency Setting Resistor Range V
+
= 2.7V | Δf
OUT
| ≤ 1.5%
| Δf
OUT
| ≤ 2.5%
| Δf
OUT
| ≤ 3.5%
●
●
20
20
400
400
400
2000
k
k
k
V
+
= 5V | Δf
OUT
| ≤ 2%
| Δf
OUT
| ≤ 3%
| Δf
OUT
| ≤ 4%
| Δf
OUT
| ≤ 4.5%
●
●
●
20
20
400
10
400
400
2000
20
k
k
k
k
Δf
OUT
/ΔT Frequency Drift Over Temperature R
SET
= 100k
●
±0.004 %/°C
Δf
OUT
/ΔV
+
Frequency Drift Over Supply (Note 4) V
+
= 2.7V to 3.6V, R
SET
= 100k
V
+
= 4.5V to 5.5V, R
SET
= 100k
●
●
0.04
0.4
0.25
0.9
%/V
%/V
Period Variation
(Frequency Spreading)
R
SET
= 100k, MOD Pin = V
+
, GND or OPEN
●
±7.5 ±10 ±12.5 %
Long-Term Stability of Output
Frequency (Note 8)
300 ppm/√kHr
Duty Cycle (Note 5) No Modulation, 250kHz ≤ f
OUT
≤ 1MHz
●
45 50 55 %
V
+
Operating Supply Range
●
2.7 5.5 V
I
S
Power Supply Current R
SET
= 2000k, R
L
= ∞, f
OUT
= 50kHz, MOD Pin = V
+
V
+
= 5V
V
+
= 2.7V
●
●
0.4
0.4
0.65
0.6
mA
mA
R
SET
= 20k, R
L
= ∞, f
OUT
= 5MHz, MOD Pin = GND
V
+
= 5V
V
+
= 2.7V
●
●
1.25
0.9
1.7
1.3
mA
mA
V
IH_MOD
High Level MOD Input Voltage
●
V
+
– 0.4 V
V
IL_MOD
Low Level MOD Input Voltage
●
0.4 V
I
MOD
MOD Pin Input Current (Note 6) MOD Pin = V
+
, V
+
= 5V
MOD Pin = GND, V
+
= 5V
●
●
–4
2
–2
4µA
µA
V
OH
High Level Output Voltage (Note 6)
(OUT1, OUT2)
V
+
= 5V I
OH
= –0.3mA
I
OH
= –1.2mA
●
●
4.75
4.4
4.9
4.7
V
V
V
+
= 2.7V I
OH
= –0.3mA
I
OH
= –0.8mA
●
●
2.35
1.85
2.6
2.2
V
V
V
OL
Low Level Output Voltage (Note 6) V
+
= 5V I
OL
= 0.3mA
I
OL
= 1.2mA
●
●
0.05
0.2
0.15
0.5
V
V
V
+
= 2.7V I
OL
= 0.3mA
I
OL
= 0.8mA
●
●
0.1
0.4
0.3
0.7
V
V
t
r
Output Rise Time (Note 7) V
+
= 5V
V
+
= 2.7V
6
11
ns
ns
t
f
Output Fall Time (Note 7) V
+
= 5V
V
+
= 2.7V
5
9
ns
ns