LTC1068 Series
8
1068fc
TYPICAL PERFORMANCE CHARACTERISTICS
LTC1068-25
Maximum Q vs Center Frequency
(Modes 1, 1b, 2)
LTC1068-25
Maximum Q vs Center Frequency
(Modes 2, 3)
LTC1068 Center Frequency
Variation vs Clock Frequency
LTC1068-200 Center Frequency
Variation vs Clock Frequency
LTC1068-50 Center Frequency
Variation vs Clock Frequency
LTC1068-25 Center Frequency
Variation vs Clock Frequency
CENTER FREQUENCY, f
O
(kHz)
0
A
B
C
TYPICAL MAXIMUM Q
55
50
45
40
35
30
25
20
15
10
5
0
64
128
160
1068 G07
32
96
192
224
A: V
S
= 3.3V, f
CLK(MAX)
= 1.2MHz
B: V
S
= 5V, f
CLK(MAX)
= 3.4MHz
C: V
S
= ±5V, f
CLK(MAX)
= 6.1MHz
(FOR MODE 2, R4 ≥ 10R2)
FREQUENCY, f
O
(kHz)
0
A
B
C
TYPICAL MAXIMUM Q
55
50
45
40
35
30
25
20
15
10
5
0
64
128
160
1068 G08
32
96
192
224
A: V
S
= 3.3V, f
CLK(MAX)
= 1MHz
B: V
S
= 5V, f
CLK(MAX)
= 3MHz
C: V
S
= ±5V, f
CLK(MAX)
= 5MHz
(FOR MODE 2, R4 < 10R2)
CLOCK FREQUENCY (MHz)
0.75 1.25 1.75 2.25 2.75 3.25 3.75
–0.6
CENTER FREQUENCY VARIATION (% ERROR)
–0.4
0
0.2
0.4
1.2
1068 G09
–0.2
4.25
0.6
0.8
1.0
MODE 3
MODE 1
V
S
= ±5V
Q = 5, REFERENCE
CENTER FREQUENCY
WITH f
CLK
= 0.75MHz
CLOCK FREQUENCY (MHz)
0.75 1.25 1.75 2.25 2.75 3.25 3.75
–0.25
CENTER FREQUENCY VARIATION (% ERROR)
–0.20
–0.10
–0.05
0
0.20
1068 G10
–0.15
4.25
0.05
0.10
0.15
MODE 3
MODE 1
V
S
= ±5V
Q = 5, REFERENCE
CENTER FREQUENCY
WITH f
CLK
= 0.75MHz
CLOCK FREQUENCY (MHz)
0.5
–0.2
CENTER FREQUENCY VARIATION (% ERROR)
–0.1
0
0.1
0.2
0.4
0.75
1.0 1.25 1.5
1068 G11
1.75 2.0
0.3
MODE 1
MODE 3
V
S
= ±5V
Q = 5, REFERENCE
CENTER FREQUENCY
WITH f
CLK
= 0.5MHz
CLOCK FREQUENCY (MHz)
0.5
0
BATTERY VOLTAGE (V)
0.3
0.8
1.3
1.8
1.0 1.5 2.0 2.5
1068 G12
3.0 3.5
MODE 1
MODE 3
V
S
= ±5V
Q = 5, REFERENCE
CENTER FREQUENCY
WITH f
CLK
= 0.5MHz
LTC1068/LTC1068-200
Noise vs Q
LTC1068-50 Noise vs Q
LTC1068-25 Noise vs Q
Q
0
0
NOISE (µV
RMS
)
50
100
150
200
10 20
30
5V
±5V
3.3V
40
1068 G13
250
300
5 15
25
35
Q
0
0
NOISE (µV
RMS
)
50
100
150
200
10 20
30
±5V
3.3V
40
1068 G14
250
300
5 15
25
35
5V
Q
0
0
NOISE (µV
RMS
)
50
100
150
200
10 20
30
±5V
3.3V
40
1068 G15
250
300
5 15
25
35
5V