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

General Description

The MAX7418–MAX7425 5th-order, low-pass, switched-

capacitor filters (SCFs) operate from a single +5V

(MAX7418–MAX7421) or +3V (MAX7422–MAX7425)

supply. These devices draw only 3mA of supply current

and allow corner frequencies from 1Hz to 45kHz, mak-

ing them ideal for low-power post-DAC filtering and anti-

aliasing applications. They feature a shutdown mode

that reduces supply current to 0.2µA.

Two clocking options are available: self-clocking

(through the use of an external capacitor), or external

clocking for tighter corner-frequency control. An offset

adjust pin allows for adjustment of the DC output level.

The MAX7418/MAX7422 deliver 53dB of stopband

rejection and a sharp rolloff with a 1.6 transition ratio.

The MAX7421/MAX7425 achieve a sharper rolloff with a

1.25 transition ratio while still providing 37dB of stop-

band rejection. The MAX7419/MAX7423 Bessel filters

provide low overshoot and fast settling, and the

MAX7420/MAX7424 Butterworth filters provide a maxi-

mally flat passband response. Their fixed response sim-

plifies the design task of selecting a clock frequency.

Applications

ADC Anti-Aliasing

CT2 Base Stations

DAC Postfiltering

Speech Processing

Features

o 5th-Order, Lowpass Filters

Elliptic Response (MAX7418/MAX7421/

MAX7422/MAX7425)

Bessel Response (MAX7419/MAX7423)

Butterworth Response (MAX7420/MAX7424)

o Clock-Turnable Corner Frequency (1Hz to 45kHz)

o Single-Supply Operation

+5V (MAX7418–MAX7421)

+3V (MAX7422–MAX7425)

o Low Power

3mA (Operating Mode)

0.2µA (Shutdown Mode)

o Available in 8-Pin µMAX Package

o Low Output Offset: ±4mV

5th-Order, Lowpass,

Switched-Capacitor Filters

________________________________________________________________ Maxim Integrated Products

1

OS

OUT

1

2

8

7

CLK

SHDN

IN

GND

COM

µMAX

TOP VIEW

3

4

6

5

MAX7418–

MAX7425

IN

CLK

OUT

GND

INPUT

0.1

µF

0.1

µF

CLOCK

SHDN

OUTPUT

COM

OS

MAX7418–

MAX7425

Typical Operating Circuit

19-1821; Rev 0; 11/00

Pin Configuration

Ordering Information

Selector Guide

PART

MAX7418EUA

-40°C to +85°C

TEMP. RANGE

PIN-PACKAGE

8 µMAX

Selector Guide continued at end of data sheet.

Ordering Information continued at end of data sheet.

MAX7418CUA

0°C to +70°C

8 µMAX

MAX7419CUA

0°C to +70°C

8 µMAX

MAX7419EUA

-40°C to +85°C

8 µMAX

MAX7420CUA

0°C to +70°C

8 µMAX

MAX7420EUA

-40°C to +85°C

8 µMAX

MAX7421CUA

0°C to +70°C

8 µMAX

MAX7421EUA

-40°C to +85°C

8 µMAX

PART

FILTER RESPONSE

OPERATING

VOLTAGE (V)

MAX7418

r = 1.6

+5

MAX7419

Bessel

+5

MAX7420

Butterworth

+5

MAX7421

r = 1.25

+5