19-0352; Rev 2; 7/02
Microprocessor Programmable
Universal Active Filters
Features
o Filter Design Software Available
o Microprocessor Interface
o 64-Step Center Frequency Control
o 128-Step Q Control
o Independent Q and f0 Programming
o Guaranteed Clock to f0 Ratio-1% (A grade)
o 75kHz f0 Range (MAX262)
o Single +5V and ±5V Operation
Ordering Information
PART
TEMP RANGE
PACKAGE
ACCURACY
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%
µP-Tuned Filters
MAX260BMRG
-55°C to +125°C
CERDIP
2%
Anti-Aliasing Filters
*All devices—24-pin packages 0.3in-wide packages
Digital Signal Processing
Ordering Information continued at end of data sheet.
Applications
Adaptive Filters
Pin Configurations
Signal Analysis
Phase-Locked Loops
Functional Diagram
TOP VIEW
IN
+5V
V+
LP HP
BP
IN
FILTER
B
FILTER
A
24 LPA
BPA 1
24 LPA
23 INB
OP OUT 2
23 INB
HPA 3
22 LPB
HPA 3
22 LPB
N.C. 4
LP HP BP
BPA 1
N.C. 2
OUTPUT
INPUT
21 BPB
OP IN 4
MAX260
21 BPB
MAX261
MAX262
20 D0
INA 5
D1 6
19 OSC OUT
D1 6
19 D0
A3 7
18 GND
A3 7
18 OSC OUT
INA 5
GND
CLK OUT 8
17 V-
V+ 9
-5V
V-
A2 10
MAX260
MAX261
MAX262
15 A0
17 GND
V+ 9
16 V15 WR
14 HPB
CLKA 11
14 A0
CLKB 12
CLKB
A2 10
CLKA 11
OSC CLKOUT
CLKA
16 WR
CLK OUT 8
20 HPB
13 A1
CLKB 12
13 A1
PROGRAM
INPUTS
CRYSTAL
FOURTH-ORDER BANDPASS FILTER
________________________________________________________________ Maxim Integrated Products
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.
1
MAX260/MAX261/MAX262
General Description
The MAX260/MAX261/MAX262 CMOS dual secondorder universal switched-capacitor active filters allow
microprocessor control of precise filter functions. No
external components are required for a variety of bandpass, lowpass, highpass, notch, and allpass configurations. Each device contains two second-order filter
sections that place center frequency, Q, and filter operating mode under programmed control.
An input clock, along with a 6-bit f0 program input,
determine the filter's center or corner frequency without
affecting other filter parameters. The filter Q is also programmed independently. Separate clock inputs for
each filter section operate with either a crystal, RC network, or external clock generator.
The MAX260 has offset and DC specifications superior
to the MAX261 and MAX262 and a center frequency
(f0) range of 7.5kHz. The MAX261 handles center frequencies to 57kHz, while the MAX262 extends the center frequency range to 140kHz by employing lower
clock-to-f0 ratios. All devices are available in 24-pin DIP
and small outline packages in commercial, extended,
and military temperature ranges.
