MAX261BEWG Maxim Integrated Products, MAX261BEWG Datasheet - Page 16

• Manufacturer Part Number: MAX261BEWG
• Description: Active Filter
• Manufacturer: Maxim Integrated Products

Specifications of MAX261BEWG

• Number Of Channels: 2
• Cutoff Frequency: 57 KHz
• Supply Voltage (max): 12.6 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Operating Supply Voltage: 5 V
• Supply Voltage (min): 4.74 V
• Package / Case: SOIC-24 Wide
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figures 7 through 11 show symbolic representations of
the MAX260 filter modes. Only one second-order sec-
tion is shown in each case. The A and B sections of
one MAX260/MAX261/MAX262 can be programmed for
Microprocessor Programmable
Universal Active Filters
Figure 6. Buffering/Latching Logic Inputs
Table 5. Filter Modes for Second-Order Functions
Notes:
16
MODE
D1
D2
1
2
3
4
A0
A1
A2
A3
______________________________________________________________________________________
-5V
OCTAL D FLIP-FLOP
13
14
WR
3
4
7
8
f
f
H
H
H
0
N
74HC374
OLP
OBP
OHP
= Center Frequency
= Notch Frequency
1D
2D
3D
4D
5D
6D
M1,
0, 0
0, 1
1, 0
1, 1
M0
OC
1
= Lowpass Gain at DC
= Highpass Gain as f approaches f
= Bandpass Gain at f
20
V
GND
FUNCTIONS
CC
LP, BP, HP
LP, BP, AP
10
LP, BP, N
LP, BP, N
FILTER
CK
1Q
2Q
3Q
4Q
5Q
6Q
11
2
5
6
9
12
15
0
f
0
A0
A1
A2
A3
D1
D2
WR
+5V
V
Q
MAX260
MAX261
MAX262
+
GND
CLK
-5V
V
-
/4
f
0
f
0
f
f
R
R
N
√2
0
H
L
different modes if desired. The f
various output gains in each case are shown in Table 5.
MODE 1 (Figure 7) is useful when implementing allpole
lowpass and bandpass filters such as Butterworth,
Chebyshev, Basset, etc. It can also be used for notch
filters, but only second-order notches because the rela-
tive pole and zero locations are fixed. Higher order
notch filters require more latitude in f
why they are more easily implemented with mode 3A.
Figure 7. Filter Mode 1: Second-Order Bandpass, Lowpass,
and Notch
H
H
H
f
z
H
ON1
ON2
OAP
, Q
IN
-0.5
OLP
-1
-1
-1
-2
z
= Notch Gain as f approaches DC
= Notch Gain as f approaches f
= Allpass Gain
= f and Q of Complex Pole Pair
SCN
H
-Q/√2
-2Q
OBP
-Q
-Q
-Q
SCN = SWITCHED-CAPACITOR NETWORK
SCN
SCN
+
-
(f ➝ 0)
+
H
-0.5
R
R
ON1
-1
G
L
+
MODE 1
(f ➝ f
Filter Mode Selection
N
Σ
+
H
-
-
R
R
ON2
-1
-1
CLK
G
H
CLK
0
, f
∫
/4)
/4
0
N
and 1
(notch), Q, and
H
H
H
f
Z
OHP
OHP
OAP
= f
∫
OTHER
N
0
, which is
= -1
, Q
= -1
= -1
Z
BP
LP
= Q