Copyright 2001 National Semiconductor Corp.

1

www.national.com

SC14405

Complete Baseband Processor for DECT Handsets with on-

chip Flash and LCD controller

General Description

The SC14405 is a CMOS chip optimized to handle all the

audio, signal and data processing needed within a DECT

handset. An ADPCM transcoder, a very low power CO-

DEC and Analog Frontend is integrated. Direct connec-

tions towards microphone and a (dynamical) loudspeaker

are provided. Duplex quality handsfree operation is inte-

grated.

The SC14405 is designed to fit to any radio design.

A dedicated TDMA controller handles all physical layer

slot formats and radio control.

National

Semiconductors

standard

CR16B 16 bit microcontroller takes care of all the higher

protocol stack. 4 kByte Flash is integrated for parameter

and number storage.

The SC14405 has an 125 segment LCD controller.

Features

I Integrated DECT Baseband transceiver optimized for

GAP handsets according to ETS 300 175-2, 175-3 &

175-8.

I Two on board low drop voltage regulators with 2.85V

and 3.0- 3.8V (with external resistors the voltage can be

determined) output.

I 2V upto 3.6V battery input with onboard step up con-

verter.

I 3V upto 5.0V battery monitor input.

I Advanced battery management unit

I Very low power in active and paging mode.

(CR16B) with programmable clock speeds.

I 4k byte memory mapped Flash

I 128 kbyte Flash or factory programmed ROM FLASH.

I 125 segment LCD controller using 5 backplanes

I 5,5 kByte on-chip Data Memory.

I One full duplex ADPCM transcoder.

I On-chip 14-bit linear CODEC.

I 14 upto 44 dB gain differential microphone input buffer.

I 100

Ω loudspeaker driver.

I Software controlled gain on audio input and output.

I Peak hold ADC for RSSI measurement.

I Five general purpose inputs can be multiplexed on an

8 bit ADC with selectable ranges.

I On-chip dedicated TDMA instruction co-processor

which supports 1.152 MHz, 0.576 MHz and 0.288 MHz

bit rates..

I 7programmable control signals for radio front end.

I Full and double slot, protected and unprotected B-

fields.Duplex quality handsfree operation.

I Tone generator. 3 parallel tones can be programmed

I Linear PCM interface for external codec.

I Four general purpose ports. Three as input/output, one

as output only.

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System Diagram

SC14405

ISDN or

Data

Interface

PSTN

Interface

SC14425

CID

Handsfree

ISDN

PSTN

SC14405

SC14405

SC14405

SC14405

APRIL 2001

V1.3