Dual Selectable Low Voltage Lowpass/Bandpass Filter

Data Sheet

09/2014

Block Diagram

Digital Levels

All the clock and control pins are referenced

between VSS and VDD. In single supply appli-

cations, the digital levels should be CMOS lev-

els from VSS to VDD. The tertiary controls (pins

- TYPE and GAIN) should be set at VSS, VREF or

VDD depending on the filter type or gain de-

Ordering Information__________

Part Number

Package

MS2LFSP

28 Pin DIP

MS2LFSS

28 Pin 300 mils wide SOIC

Absolute Maximum Ratings

Power Supply Voltage

+5V

Storage Temperature

-60 to +150 C

Operating Temperature

0 to 70C

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Mixed Signal Integration Corporation reserves the right to to change any product or specification without notice at any time. Mixed Signal Integration

products are not designed or authorized for use in life support systems. Mixed Signal Integration assumes no responsibility for errors in this docu-

ment.

The Gain control pin G is a tertiary control pin where

state 0 is VSS, state 1 is GND level and state 2 is VDD.

G

Gain

0

OdB

1

6dB

2

12dB

The frequency control pin F0 is a CMOS level pin

where high is clock to corner of 85.3 to 1 (170.6 to 1

for Bessel) and low is clock to corner of 42.65 to 1

(85.3 to 1 for Bessel).

FSEL=0

FSEL=1

TYPE

Lowpass

Bandpass

0

Butterworth

Full Octave

1

Bessel

Third Octave

2

Elliptic

Sixth Octave

The filter type is selected using the two filter select pins,

TYPE and FSEL, FSEL is a CMOS level pin that selects

lowpass or bandpass (lowpass = 0, bandpass = 1). TYPE

Is a tertiary control pin that selects the filter response.

State 0 is VSS, state 1 is GND and state 2 is VDD.

Filter Selection________________

FSEL A

TYPE A

GAIN A

MIC OUT

MIC IN

SCF

Out A

MIC

Section

VREF

One

PD MIC

Clock

PD A

PD B

Fo

CTVL

PWR

Out B

SCF

IN B

PD Out B

Section

Out B

Three

FSEL B

TYPE B

Adjustable

Gain

SCF

Section

Two

SCF

Section

Three

SCF

Lowpass

Buffer

SCF

Section

Two

SCF

Section

One

SCF

Lowpass

Buffer

Clock

Divider

Low

Voltage

Circuitry