Copyright 2000 National Semiconductor Corp.

1

www.national.com

SC14404

Complete Baseband Processor for DECT Handsets

General Description

The SC14404 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 SC14404 is designed to fit to any radio design.

A dedicated TDMA controller handles all physical layer

slot formats and radio control.

National

Semiconductors

standard

CompactRISC

TM

CR16B 16 bit microcontroller takes care of all the higher

protocol stack. 4 kilobyte F lash is integrated for parameter

and number storage.

Features

n Integrated DECT Baseband transceiver optimized for

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

175-8.

n Two on board low drop voltage regulators with 2.85V

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

determined) output.

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

verter.

n 3V upto 5.0V battery monitor input.

n Advanced battery management unit

n Very low power in active and paging mode.

(CR16B) with programmable clock speeds.

n 4k byte memory mapped Flash

n 320 kbyte Flash or factory programmed ROM FLASH.

n 5,5 kilobyte on-chip Data Memory.

n One full duplex ADPCM transcoder.

n On-chip 14-bit linear CODEC.

n 14 upto 44 dB gain differential microphone input buffer.

n 100

Ω loudspeaker driver.

n Software controlled gain on audio input and output.

n Peak hold ADC for RSSI measurement.

n Five general purpose inputs can be multiplexed on an

8 bit ADC with selectable ranges.

n On-chip dedicated TDMA instruction co-processor

which supports 1.152 MHz, 0.576 MHz and 0.288 MHz

bit rates.

n Seven programmable control signals for radio front

end.

n Full and double slot, protected and unprotected B-

fields.

n Duplex quality handsfree operation.

n Tone generator. Tones consisting of 3 frequencies can

be programmed

n Linear PCM interface for external codec.

________________________________________________________________________________________________

System Diagram

PRELIMINARY

FEBRUARY 2000

Note: ACCESSBUS

marks of National Semiconductor Corporation.