MC145076

MOTOROLA

1

Product Preview

MC145076 Stereo Audio FIR

Smoothing Filter

CMOS

The MC145076 is a combination re–clocking and smoothing filter designed

especially for the MC145074 Stereo Audio DAC. Its versatility however, allows

it to be used with any single bit–stream data converter to provide output

reconstruction filtering, and to improve performance by restoring pulse shape

integrity. The MC145076 provides a well controlled, filtered output that can be

used directly, or with a current summing operational amplifier.

The MC145076 is intended to be one half of a two–chip solution for serial bit

steam DACs. The analog filtering function of the MC145076 eases the digital

filtering requirements at the input to the digital noise shaping modulator, and

eliminates the need for precision analog output filtering capacitors, resulting in

lower overall system cost. The MC145076 pulse shape restoration frees the

designer from analog pitfalls that can impact performance, thereby lowering the

risk of new product development with a sigma–delta DAC.

• Single–Ended Stereo Outputs Require no Additional Smoothing Filters

• 86 dB S/D, 96 dB S/N with MC145074 @ 192 x OSR Single Ended

• > 100 dB S/(N+D) @ 256 OSR, Differential Mode

• 18.5 MHz Maximum Serial Data Input Rate

• – 80 dB Cross Channel Interference

• 72–Tap FIR with > 40 dB Alias Filtering

• Operating Temperature Range: – 40 to + 85_C

• Buffered Data Clock Output for Ease of Data Generation

• 16–Pin Narrow Body SOIC Package

• Single Supply Operation: + 5 V

TIMING

AND

CONTROL

LOGIC

DIL

5

DIR

6

DIV2

4

TEST

7

Xout

Xin

16

2

VDDA

1

VDDD

8

GND

10

GND

15

LEFT 144 SERIAL SHIFT REG.

LEFT CHOP

C (1)

14

IOL

GND

144 TAP HAMMING

WINDOW

COEFFICIENTS

13

9

CLKOUT

RIGHT 144 SERIAL SHIFT REG.

RIGHT CHOP

C (1)

11

IOR

GND

144 TAP HAMMING

WINDOW

COEFFICIENTS

12

C (144)

C (144)

BIAS

3

This document contains information on a product under development. Motorola reserves the right to change or discontinue this product without notice.

Order this document

by MC145076/D

MOTOROLA

SEMICONDUCTOR TECHNICAL DATA

PIN ASSIGNMENT

MC145076

D SUFFIX

16–PIN SOG

CASE 751B–05

ORDERING INFORMATION

MC145076D

SOG Package

13

14

15

16

9

10

11

12

5

4

3

2

1

8

7

6

GND

GND

IOL

GND

Xout

CLKOUT

GND

IOR

DIV2

BIAS

Xin

VDDA

VDDD

TEST

DIR

DIL

16

1

REV 1

9/96