LTC1068 Series
ELECTRICAL CHARACTERISTICS LTC1068-25 (Complete Filter). The
●
denotes the specifications which
apply over the full operating temperature range, otherwise specifications are at V = ±5V, T = 25°V, unless otherwise noted.
S
A
PARAMETER
CONDITIONS
V = ±5V, f
MIN
TYP
MAX
UNITS
DC Offset Voltage (Note 5)
(See Table 1)
= 1MHz, V
OS1
●
●
●
0
±15
mV
S
CLK
(DC Offset of Input Inverter)
V = ±5V, f = 1MHz, V
OS2
–2
–5
± 25
± 40
mV
mV
S
CLK
(DC Offset of First Integrator)
V = ±5V, f = 1MHz, V
S
CLK
OS3
(DC Offset of Second Integrator)
Clock Feedthrough
V = ±5V, f = 1MHz
0.25
5.6
mV
RMS
S
CLK
Max Clock Frequency (Note 6)
Power Supply Current
V = ±5V, Q ≤ 1.6, Mode 1
S
MHz
V = 3.14V, f
V = 4.75V, f
S
= 1MHz (Note 2)
= 1MHz (Note 3)
●
●
●
3.5
6.5
9.5
8
11
15
mA
mA
mA
S
CLK
CLK
V = ±5V, f
S
= 1MHz
CLK
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: Production testing for single 3.14V supply is achieved by using
the equivalent dual supplies of ±1.57V.
Note 4: Pin 7 (AGND) is the internal analog ground of the device. For
single supply applications this pin should be bypassed with a 1µF
capacitor. The biasing voltage of AGND is set with an internal resistive
divider from Pin 8 to Pin 23 (see Block Diagram).
Note 5: Side D is guaranteed by design.
Note 6: See Typical Performance Characteristics.
Note 3: Production testing for single 4.75V supply is achieved by
using the equivalent dual supplies of ±2.375V.
Table 1. Output DC Offsets One 2nd Order Section
MODE
V
V
V
V
V
OSN
OSBP
OSLP
1
1b
2
[(1/Q) + 1 + ||HOLP||] – V /Q
V
V
– V
OS1
OS1
OS3
OS3
OS3
OS3
OSN OS2
[(1/Q) + 1 + R2/R1] – V /Q
V
~(V
– V )(1 + R5/R6)
OSN OS2
OS3
[V (1 + R2/R1 + R2/R3 + R2/R4) – V (R2/R3)X
V
V – V
OSN OS2
OS1
OS3
[R4/(R2 + R4)] + V [R2/(R2 + R4)]
OS2
3
V
V
V [1 + R4/R1 + R4/R2 + R4/R3] – V (R4/R2) – V (R4/R3)
OS1 OS2 OS3
OS2
OS3
W
U
TYPICAL PERFORMANCE CHARACTERISTICS
LTC1068
Maximum Q vs Center Frequency
(Modes 1, 1b, 2)
LTC1068-200
Maximum Q vs Center Frequency
(Modes 1, 1b, 2)
LTC1068
Maximum Q vs Center Frequency
(Modes 2, 3)
55
50
45
40
35
30
25
20
15
10
5
50
45
40
35
30
25
20
15
10
5
50
45
40
35
30
25
20
15
10
5
A: V = 3.3V, f
S
= 1.2MHz
= 3.2MHz
= 6.1MHz
CLK(MAX)
A. V = 3.3V, f
S
= 1.5MHz
= 3.4MHz
= 5.6MHz
CLK(MAX)
CLK(MAX)
CLK(MAX)
A. V = 3.3V, f
= 1MHz
= 3MHz
CLK(MAX)
S
CLK(MAX)
B: V = 5V, f
B. V = 5V, f
S
S
CLK(MAX)
S
S
CLK(MAX)
B. V = 5V, f
S
C: V = ± 5V, f
C. V = ± 5V, f
C. V = ± 5V, f
= 5MHz
(FOR MODE 2 R4 < 10R2)
S
CLK(MAX)
(FOR MODE 2 R4 ≥ 10R2)
(FOR MODE 2, R4 ≥ 10R2)
A
B
C
A
B
C
A
B
C
0
0
0
0
20
30
40
50
60
70
10
0
8
12 16 20 24
CENTER FREQUENCY, f (kHz)
32
4
28
0
20
30
40
50
60
10
CENTER FREQUENCY, f (kHz)
O
O
1068 G01
1068 G03
CENTER FREQUENCY, f (kHz)
O
1068 G02
1068fb
6