General Description

The MAX291/MAX292/MAX295/MAX296 are easy-to-use,

8th-order, lowpass, switched-capacitor filters that can be

set up with corner frequencies from 0.1Hz to 25kHz

(MAX291/MAX292) or 0.1Hz to 50kHz (MAX295/MAX296).

The MAX291/MAX295 Butterworth filters provide maxi-

mally flat passband response, and the MAX292/MAX296

Bessel filters provide low overshoot and fast settling. All

four filters have fixed responses, so the design task is

limited to selecting the clock frequency that controls the

filter’s corner frequency.

An external capacitor is used to generate a clock using

the internal oscillator, or an external clock signal can be

used. An uncommitted operational amplifier (noninverting

input grounded) is provided for building a continuous-

time lowpass filter for post-filtering or anti-aliasing.

Produced in an 8-pin DIP/SO and a 16-pin wide SO

package, and requiring a minimum of external compo-

nents, the MAX291 series delivers very aggressive per-

formance from a tiny area.

Applications

ADC Anti-Aliasing Filter

Noise Analysis

DAC Post-Filtering

50Hz/60Hz Line-Noise Filtering

Features

o 8th-Order Lowpass Filters:

Butterworth (MAX291/MAX295)

Bessel

(MAX292/MAX296)

o Clock-Tunable Corner-Frequency Range:

0.1Hz to 25kHz (MAX291/MAX292)

0.1Hz to 50kHz (MAX295/MAX296)

o No External Resistors or Capacitors Required

o Internal or External Clock

o Clock to Corner Frequency Ratio:

100:1 (MAX291/MAX292)

50:1 (MAX295/MAX296)

o Low Noise: -70dB THD + Noise (Typ)

o Operate with a Single +5V Supply or

Dual ±5V Supplies

o Uncommitted Op Amp for Anti-Aliasing or Clock-

Noise Filtering

o 8-Pin DIP and SO Packages

8th-Order, Lowpass,

Switched-Capacitor Filters

________________________________________________________________

Maxim Integrated Products

1

19-4526; Rev 4; 4/09

Ordering Information

Pin Configurations

Ordering Information continued on last page.

* Contact factory for dice specifications.

** Contact factory for availability and processing to MIL-STD-883.

PART

TEMP. RANGE

PIN-PACKAGE

MAX291CPA

MAX291CWE

0°C to +70°C

8 Plastic DIP

MAX291C/D

0°C to +70°C

0°C to +70°C

16 Wide SO

Dice*

MAX291EPA

-40°C to +85°C

8 Plastic DIP

MAX291EWE

MAX291MJA

-55°C to +125°C

-40°C to +85°C

16 Wide SO

8 CERDIP**

GND

OP OUT

OUT

OP IN-

1

2

8

7

IN

V+

V-

CLK

MAX29_

DIP/SO

TOP VIEW

3

4

6

5

16-pin Wide SO on last page.

MAX291CSA

0°C to +70°C

8 SO

MAX291ESA

-40°C to +85°C

8 SO

+5V

-5V

V+

V-

8

7

1

6

2

4

3

5

CLOCK

CLK

OP IN-

OP OUT

OUT

OUTPUT

INPUT

IN

MAX29_

Typical Operating Circuit

Pin Configuration is 8-pin DIP/SO.

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.