LTC1069-7IS8 Linear Technology, LTC1069-7IS8 Datasheet - Page 8

• Manufacturer Part Number: LTC1069-7IS8
• Description: IC FILTR 8TH ORDER LOWPASS 8SOIC
• Manufacturer: Linear Technology

Specifications of LTC1069-7IS8

• Filter Type: Linear Phase, Lowpass Switched Capacitor
• Frequency - Cutoff Or Center: 200kHz
• Number Of Filters: 1
• Max-order: 8th
• Voltage - Supply: ±5 V, 5 V
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

LTC1069-7
APPLICATIONS INFORMATION
Wideband Noise
The wideband noise of the fi lter is the total RMS value
of the device’s noise spectral density and determines the
operating signal-to-noise ratio. Most of the wideband
noise frequency contents lie within the fi lter passband.
The wideband noise cannot be reduced by adding post
fi ltering. The total wideband noise is nearly independent
of the clock frequency and depends slightly on the power
supply voltage (see Table 3). The clock feedthrough
specifi cations are not part of the wideband noise.
Table 3. Wideband Noise
Aliasing
Aliasing is an inherent phenomenon of sampled data
systems and it occurs for input frequencies approaching
the sampling frequency. The internal sampling frequency
of the LTC1069-7 is 50 times its f
instance if a 48kHz, 100mV
8
4.75V
±5V
V
S
RMS
CLOCK FEEDTHROUGH
signal is applied at the
CUTOFF
125μV
140μV
RMS
RMS
frequency. For
input of an LTC1069-7 operating with a 50% duty cycle
25kHz clock, a 2kHz, 741μV
at the fi lter output. Table 4 shows details.
Table 4. Aliasing
f
Speed Limitations
To avoid op amp slew rate limiting, the signal amplitude
should be kept below a specifi ed level as shown in Table 5.
Table 5. Maximum V
CLK
48.5kHz (or 51.5kHz)
49.5kHz (or 50.5kHz)
INPUT FREQUENCY
40kHz (or 60kHz)
47kHz (or 53kHz)
48kHz (or 52kHz)
49kHz (or 52kHz)
/f
V
C
IN
= 25:1, f
±5V
5V
V
= 1V
S
RMS
CUTOFF
MAXIMUM CLOCK
= 1kHz
IN
vs V
Relative to Input
OUTPUT LEVEL
≥ 2.5MHz
≥ 4.5MHz
–59.9dB
–54.2dB
–42.6dB
–18.3dB
–0.65dB
S
–2.9dB
and Clock
RMS
alias signal will appear
340mV
1.2V
OUTPUT FREQUENCY
Aliased Frequency
MAXIMUM V
RMS
RMS
(f
1.5kHz
1.0kHz
0.5kHz
10kHz
(f
3kHz
2kHz
IN
IN
≥ 400kHz)
≥ 200kHz)
IN
10697fa