MAX7418–MAX7425
5th-Order, Lowpass,
Switched-Capacitor Filters
_______________________________________________________________________________________ 5
FILTER CHARACTERISTICS
(V
DD
= +5V for MAX7418-MAX7420, V
DD
= +3V for MAX7422-MAX7425 filter output measured at OUT, 10kΩ || 50pF load to GND at
OUT, SHDN = V
DD
, f
CLK
= 2.2MHz, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
Note 1: The maximum f
C
is defined as the clock frequency f
CLK
= 100 x f
C
at which the peak S / (THD+N) drops to 68dB with a
sinusoidal input at 0.2f
C
. Maximum f
C
increases as V
IN
signal amplitude decreases.
Note 2: DC insertion gain is defined as ΔV
OUT
/ ΔV
IN
.
Note 3: MAX7418/MAX7421/MAX7422/MAX7425: f
OSC
(kHz) ≅ 87x10
3
/ C
OSC
(pF).
MAX7419/MAX7420/MAX7423/MAX7424: f
OSC
(kHz) ≅ 110x10
3
/ C
OSC
(pF).
Note 4: PSRR is the change in output voltage from a V
DD
of 4.5V and a V
DD
of 5.5V.
BESSEL FILTERS—MAX7409/MAX7413
dB
-67 -60f
IN
= 7f
C
Insertion Gain Relative to
DC Gain
-41.0 -35f
IN
= 7f
C
-3.6 -3.0 -2.4
-1.0 -0.74f
IN
= 0.5f
C
f
IN
= 4f
C
Insertion Gain Relative to
DC Gain
-70 -65f
IN
= 5f
C
-47.5 -43
Insertion Gain Relative to
DC Gain
-3.6 -3.0 -2.4f
IN
= f
C
f
IN
= 3f
C
-0.3 0
dB
f
IN
= 0.5f
C
-67 -60
dB
f
IN
= 7f
C
-41.0 -35f
IN
= 4f
C
-3.6 -3.0 -2.4f
IN
= f
C
-1 -0.74f
IN
= 0.5f
C
PARAMETER MIN TYP MAX UNITSCONDITIONS
-0.4 -0.2 0.4f
IN
= 0.68f
C
-0.4 -0.2 0.4f
IN
= 0.87f
C
-0.4 -0.2 0.4f
IN
= 0.97f
C
-0.7 -0.2 0.2f
IN
= f
C
-36 -33f
IN
= 1.25f
C
-37.2 -35f
IN
= 1.43f
C
Insertion Gain with DC Gain
Error Removed (Note 4)
-37.2 -35
dB
f
IN
= 3.25f
C
-0.4 -0.2 0.4f
IN
= 0.38f
C
BESSEL FILTERS—MAX7419/MAX7423
BUTTERWORTH FILTERS—MAX7420/MAX7424
BESSEL FILTERS—MAX7419/MAX7423
ELLIPTIC, R = 1.2—MAX7421/MAX7425
