LTC1569CS8-7#TRPBF Linear Technology, LTC1569CS8-7#TRPBF Datasheet - Page 7

• Manufacturer Part Number: LTC1569CS8-7#TRPBF
• Description: IC FILTER 10TH ORDR LOWPASS8SOIC
• Manufacturer: Linear Technology

Specifications of LTC1569CS8-7#TRPBF

• Filter Type: Linear Phase, Lowpass Switched Capacitor
• Frequency - Cutoff Or Center: 300kHz
• Number Of Filters: 1
• Max-order: 10th
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -

APPLICATIONS
The cutoff frequency is easily estimated from the equation
in Figure 1. Examples 1 and 2 illustrate how to use the
graphs in Figures 2 through 7 to get a more precise
estimate of the cutoff frequency.
Example 1: LTC1569-7, R
mode, DIV/CLK (Pin 5) connected to V
Using the equation in Figure 1, the approximate filter
cutoff frequency is f
• (1/16) = 4kHz.
For a more precise f
a value of f
in Figure 6 to find the correct divide ratio when V
and R
= 64kHz • (20.18k/20k) • (1/16.02) = 4.03kHz.
EXT
Figure 5. Filter Cutoff vs Temperature,
Divide-by-4 Mode, R
1.010
1.008
1.006
1.004
1.002
1.000
0.998
0.996
0.994
0.992
0.990
= 20k. Based on Table 1 and Figure 6, f
CUTOFF
–50
U
–25
V
V
V
when R
S
S
S
= 3V
= 5V
= 10V
CUTOFF
TEMPERATURE ( C)
INFORMATION
CUTOFF
EXT
0
U
EXT
= 20k, V
EXT
estimate, use Table 1 to get
25
= 10k
= 20k and use the graph
= 128kHz • (10k/20k)
50
W
S
+
= 3V, divide-by-16
(Pin 7), T
75
1569-7 F05
1.010
1.008
1.006
1.004
1.002
1.000
0.998
0.996
0.994
0.992
0.990
Figure 7. Filter Cutoff vs Temperature,
Divide-by-16 Mode, R
100
–50
U
A
= 25 C.
–25
CUTOFF
S
V
V
V
S
S
S
= 3V
= 3V
= 5V
= 10V
TEMPERATURE ( C)
0
25
Example 2: LTC1569-7, R
mode, DIV/CLK (Pin 5) connected to V
EXT
From Table 1, the part-to-part variation of f
be 2%. From the graph in Figure 7, the 0 C to 70 C
drift of f
Using the equation in Figure 1, the approximate filter
cutoff frequency is f
• (1/1) = 256kHz.
For a more precise f
f
correct for the supply voltage when V
Table 1 and Figure 2, f
0.970 = 249kHz.
= 10k
CUTOFF
50
75
CUTOFF
16.32
16.16
16.00
15.84
1569-7 F07
frequency for R
Figure 6. Typical Divide Ratio in the
Divide-by-16 Mode, T
100
2
will be – 0.2% to 0.2%.
R
R
R
R
EXT
EXT
EXT
EXT
4
CUTOFF
= 5k
= 10k
= 20k
= 40k
EXT
CUTOFF
V
CUTOFF
SUPPLY
EXT
6
estimate, use Table 1 to get
= 5k, V
A
= 5k and use Figure 2 to
= 25 C
(V)
= 128kHz • (10k/5k)
= 256k • (5.01k/5k) •
LTC1569-7
8
S
–
(Pin 4), T
= 5V, divide-by-1
1569-7 F06
S
10
= 5V. From
CUTOFF
A
= 25 C.
7
will