MAX7490CEE Maxim Integrated Products, MAX7490CEE Datasheet - Page 14
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MAX7490CEE
Manufacturer Part Number
MAX7490CEE
Description
Active Filter
Manufacturer
Maxim Integrated Products
Datasheet
1.MAX7490EEE.pdf
(18 pages)
Specifications of MAX7490CEE
Number Of Channels
2
Cutoff Frequency
40 KHz
Supply Voltage (max)
5.5 V
Maximum Operating Temperature
+ 70 C
Minimum Operating Temperature
0 C
Mounting Style
SMD/SMT
Operating Supply Voltage
5 V
Supply Voltage (min)
4.5 V
Package / Case
QSOP-16
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
MAX7490CEE
Manufacturer:
MAXIM/美信
Quantity:
20 000
Company:
Part Number:
MAX7490CEE+
Manufacturer:
Maxim
Quantity:
180
Dual Universal Switched-Capacitor Filters
Mode 3A Design Equations
Note: When the passband gain error exceeds 1dB, the
use of capacitor C
the inverting input will reduce the gain error. The value
can best be determined experimentally. Typically, it
should be about 5pF/dB (C
14
Table 3. Suggested External Op Amps
Figure 8. Block Diagram of a 2nd-Order Section Showing the Input Offsets
______________________________________________________________________________________
MAX4281
MAX4322
MAX4130
MAX4490
PART
f
f
Q
H
H
H
H
H
O
n
OHP
OLP
OBP
ON
ON
=
=
=
R
R
1
2
f
f
100
CLK
100
(
CLK
3
2
(
f
=
at f
=
=
→
−
−
−
R
R
R
R
R
R
R
R
C
0
=
1
1
1
INV
COM
2
4
4
2
3
Hz
R
R
R
f
R
between the lowpass output and
CLK
H
L
2
4
)
=
V
OS1
R
/ )
R
C-MAX
2
G
L
GBW (MHz)
=
⎛
⎜
⎝
R
R
R
R
4
10
10
1
G
H
2
5
= 15pF).
⎞
⎟
⎠
⎛
⎜
⎝
R
R
2
1
⎞
⎟
⎠
N/HP
+
SLEW RATE (V/μs)
Σ
S
-
10.0
0.7
2.0
4.0
V
OS2
Switched-capacitor integrators generally exhibit higher
input offsets than discrete RC integrators. The larger
offset is mainly due to the charge injection of the CMOS
switches into the integrating capacitors. The internal op
amp offset also adds to the overall offset value. Figure
8 shows the input offsets from a single 2nd-order sec-
tion. Table 4 lists the formula for the output offset volt-
age for various modes and output pins.
The MAX7490 operates from a single +5V supply, and
the MAX7491 operates from a single +3V supply.
Bypass V
V
age analog supplies. If dual supplies are required, con-
nect the COM pin to the system ground and the GND
pin to the negative supply. Figure 9 shows an example
of dual-supply operation. Single-supply and dual-sup-
ply performances are equivalent. For dual-supply oper-
ation, drive CLK, SHDN, and EXTCLK from GND (which
is now V-) to V
supply mode, C
the actual ground voltage. Use the MAX7490 for ±2.5V
and use the MAX7491 for ±1.5V.
For most applications, a 0.1µF bypass capacitor from
COM to GND is sufficient. If the V
cant 60Hz energy, increase this capacitor to 1µF or
greater to provide better power-supply rejection.
DD
∫
should be isolated from other digital or high-volt-
DD
I SUPPLY/AMP (mA)
BP
to GND with at least a 0.1µF capacitor.
DD
OSC
V
. If using the internal oscillator in dual-
OS3
1.15
0.5
1.1
2.0
can be returned to either GND or
∫
LP
DD
Power Supplies
Offset Voltage
PIN-PACKAGE
supply has signifi-
5 SOT23
5 SOT23
5 SOT23
5 SOT23