MSM7532 View Datasheet(PDF) - Oki Electric Industry

Part Name

Description

Manufacturer

MSM7532

Single Chip MSK Modem with Compandor for Cordless Telephone

Oki Electric Industry 

¡ Semiconductor

MSM7532

The DC clamp level is VSG ±VLIML.

LIML

+

–

Inverter

From LPF1

Limiter

To splatter filter

CPDL

Input DC voltage reference level definition pin for compander.

One of the voltages into which the voltage between VREF pin and SGO pin is divided by the resistors

should be supplied to this pin. Refor to the VREF description for voltage division by the resistors.

If the potential difference between this pin and the SGO pin is VCPDL, the compressor and expander

input reference levels are expressed as follows.

VICS = VIES = 20 · log (VCPDL) – 5.8 (dBV)

The compressor input reference level and expander input reference level change simultaneously.

SGI

Built-in signal ground that is reference voltage to be supplied to analog circuit.

The DC voltage is one half of the supply voltage.

When the power has fewer noises and fewer ripples, the idle noise can be improved by inserting a

bypass capacitor over 1 mF between SGI and GND, and between SGI and VDD. If the power has a lot

of noises, do not insert a bypass capacitor between SGI and VDD to reduce supply noises.

Other capacitors and resistors should be connected to the SGO pin.

SGO

Signal ground voltage output pin for LSI external circuits.

The DC voltage is one half of the supply voltage.

Insert a 1 mF capacitor between SGO and GND.

VDD

To internal circuit

SG voltage

generation circuit

C2

SGI

C3

+

SGO

–

C25

BR

MODEM data signaling rate switching input.

BR Data Signaling Rate Note

0

1200 bps

SW8

1

2400 bps

CE3P, CE3N

Pins used to connect a capacitor for defining a time constant of output transient response for the

expander.

Insert a 0.22 mF capacitor between CE3N and CE3P.

8/21

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