LTC1562-2_15 Datasheet, PDF (1/16 Pages) Linear Technology – Very Low Noise, Low Distortion Active RC Quad Universal Filter

LTC1562-2
Very Low Noise, Low Distortion
Active RC Quad Universal Filter
FEATURES
s _{Continuous Time—No Clock}
s _{Four 2nd Order Filter Sections, 20kHz to 300kHz}
Center Frequency
s _{Butterworth, Chebyshev, Elliptic or Equiripple}
Delay Response
s _{Lowpass, Bandpass, Highpass Responses}
s _{99dB Typical S/N, ±5V Supply (Q = 1)}
s _{93dB Typical S/N, Single 5V Supply (Q = 1)}
s _{Rail-to-Rail Input and Output Voltages}
s _{DC Accurate to 3mV (Typ)}
s _{±0.5% Typical Center Frequency Accuracy}
s _{“Zero-Power” Shutdown Mode}
s _{Single or Dual Supply, 5V to 10V Total}
s _{Resistor-Programmable fO, Q, Gain}
U
APPLICATIO S
s _{High Resolution Systems (14 Bits to 18 Bits)}
s _{Antialiasing/Reconstruction Filters}
s _{Data Communications, Equalizers}
s _{Dual or I-and-Q Channels (Two Matched 4th Order}
Filters in One Package)
s _{Linear Phase Filtering}
s _{Replacing LC Filter Modules}
DESCRIPTIO
The LTC^®1562-2 is a low noise, low distortion continuous
time filter with rail-to-rail inputs and outputs, optimized for a
center frequency (f_O) of 20kHz to 300kHz. Unlike most
monolithic filters, no clock is needed. Four independent 2nd
order filter blocks can be cascaded in any combination, such
as one 8th order or two 4th order filters. Each block’s
response is programmed with three external resistors for
center frequency, Q and gain, using simple design formulas.
Each 2nd order block provides lowpass and bandpass out-
puts. Highpass response is available if an external capacitor
replaces one of the resistors. Allpass, notch and elliptic
responses can also be realized.
The LTC1562-2 is designed for applications where dynamic
range is important. For example, by cascading 2nd order
sections in pairs, the user can configure the IC as a dual 4th
order Butterworth lowpass filter with 90dB signal-to-noise
ratio from a single 5V power supply. Low level signals can
exploit the built-in gain capability of the LTC1562-2. Varying
the gain of a section can achieve a dynamic range as high as
114dB with a ±5V supply.
Other cutoff frequency ranges can be provided upon request.
Please contact LTC Marketing.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
Dual 4th Order 200kHz Butterworth Lowpass Filter, SNR 96dB
R_IN2 7.87k
R_IN1 7.87k
V_IN1
R_Q1 4.22k
R21 7.87k
5V
0.1µF
R23 7.87k
R_Q3 4.22k
R_IN3 7.87k
V_IN2
*V ^– ALSO AT PINS 4, 7, 14 & 17
ALL RESISTORS 1% METAL FILM
1
INV B
20
INV C
2
V1 B
19
V1 C
3
V2 B
18
V2 C
5 _{V+ LTC1562-2 V –} 16
6
SHDN
15
AGND
8
V2 A
13
V2 D
9
V1 A
12
V1 D
10
INV A
11
INV D
R_Q2 10.2k
R22 7.87k
R24 7.87k
R_Q4 10.2k
0.1µF
R_IN4 7.87k
1562-2 TA01
V_OUT1
– 5V*
V_OUT2
10
0
–10
–20
–30
–40
–50
–60
–70
–80
50k
Amplitude Response
100k
FREQUENCY (Hz)
1M 1.5M
1562-2 TA02
15622fa
1