Datasheet

General Description
The MAX260/MAX261/MAX262 CMOS dual second-
order universal switched-capacitor active filters allow
microprocessor control of precise filter functions. No
external components are required for a variety of band-
pass, lowpass, highpass, notch, and allpass configura-
tions. Each device contains two second-order filter
sections that place center frequency, Q, and filter oper-
ating mode under programmed control.
An input clock, along with a 6-bit f
0
program input,
determine the filter's center or corner frequency without
affecting other filter parameters. The filter Q is also pro-
grammed independently. Separate clock inputs for
each filter section operate with either a crystal, RC net-
work, or external clock generator.
The MAX260 has offset and DC specifications superior
to the MAX261 and MAX262 and a center frequency
(f
0
) range of 7.5kHz. The MAX261 handles center fre-
quencies to 57kHz, while the MAX262 extends the cen-
ter frequency range to 140kHz by employing lower
clock-to-f
0
ratios. All devices are available in 24-pin DIP
and small outline packages in commercial, extended,
and military temperature ranges.
Applications
µP-Tuned Filters
Anti-Aliasing Filters
Digital Signal Processing
Adaptive Filters
Signal Analysis
Phase-Locked Loops
Features
♦ Filter Design Software Available
♦ Microprocessor Interface
♦ 64-Step Center Frequency Control
♦ 128-Step Q Control
♦ Independent Q and f
0
Programming
♦ Guaranteed Clock to f
0
Ratio-1% (A grade)
♦ 75kHz f
0
Range (MAX262)
♦ Single +5V and ±5V Operation
MAX260/MAX261/MAX262
Microprocessor Programmable
Universal Active Filters
________________________________________________________________ Maxim Integrated Products 1
24
23
22
21
20
19
18
17
1
2
3
4
5
6
7
8
LP
A
IN
B
LP
B
BP
B
N.C.
HP
A
N.C.
BP
A
TOP VIEW
D0
OSC OUT
GND
V
-
CLK OUT
A3
D1
IN
A
16
15
14
13
9
10
11
12
WR
A0
HP
B
A1CLK
B
CLK
A
A2
V
+
MAX260
24
23
22
21
20
19
18
17
1
2
3
4
5
6
7
8
LP
A
IN
B
LP
B
BP
B
OP IN
HP
A
OP OUT
BP
A
HP
B
D0
OSC OUT
V
-
CLK OUT
A3
D1
IN
A
16
15
14
13
9
10
11
12
WR
GND
A0
A1CLK
B
CLK
A
A2
V
+
MAX261
MAX262
Pin Configurations
Ordering Information
OUTPUT
BPHPLPIN
BPHPLPIN
INPUT
+5V V
+
GND
-5V V
-
CLK
A
OSC CLKOUT
CLK
B
PROGRAM
INPUTS
CRYSTAL
FOURTH-ORDER BANDPASS FILTER
MAX260
MAX261
MAX262
FILTER
A
FILTER
B
Functional Diagram
19-0352; Rev 2; 7/02
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
PART TEMP RANGE PACKAGE A C C U R A C Y
MAX260ACNG 0°C to +70°C Plastic DIP 1%
MAX260BCNG 0°C to +70°C Plastic DIP 2%
MAX260AENG -40°C to +85°C Plastic DIP 1%
MAX260BENG -40°C to +85°C Plastic DIP 2%
MAX260ACWG 0°C to +70°C Wide SO 1%
MAX260BCWG 0°C to +70°C Wide SO 2%
MAX260AMRG -55°C to +125°C CERDIP 1%
MAX260BMRG -55°C to +125°C CERDIP 2%
*All devices—24-pin packages 0.3in-wide packages
Ordering Information continued at end of data sheet.