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 CompactRISC
TM
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.
I
Embedded 16 bit CompactRISC
TM
Micro Controller.
(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
ACCESSBUS
TM
or MICROWIRE
TM
interfaces
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
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.
________________________________________________________________________________________________
System Diagram
SC14405
ISDN or
Data
PSTN
Interface
SC14425
CID
Handsfree
ISDN
PSTN
SC14405
SC14405
SC14405
SC14405
APRIL 2001
V1.3
S
Note: ACCESSBUS
TM
, MICROWIRE
TM
and CompactRISC
TM
are trademarks of National Semiconductor Corporation.-