User's Manual

REPORT NO : HCT-F02-1104 FCC ID : N5ZDN308 DATE : NOVEMBER 12, 2002
HYUNDAI CALIBRATION & CERTIFICATION TECHNOLOGIES CO., LTD.
SAN 136-1, AMI-RI , BUBAL-EUP, ICHEON-SI,KYOUNKI-DO, 467-701,KOREA
TEL : [phone] FAX : [phone]
4-1-3. Memory Block
Model Flash Memory(Nand Type) Manufacture
DN308 8Mbyte x 8bit(64Mbit) Samsung/Toshiba
Flash memory on the memory block is used to store the voice data. DN308 is only different from
the memory size. The table below shows the memory device for each model.
4-1-4. Audio block
- Mic. Amp
Input audio signal from the built-in microphone or external microphone is amplified by this block
and sent to the CODEC IC.
This circuit also includes AGC(Automatic Gain Controller) circuit. The power of the Mic. Amp.
circuit is controlled by the CPU.
- Speaker Amp.
The output audio signal from the CODEC is too small to drive Speaker. So this amplifier circuit
using Low Voltage Audio Amp.
(IC2) amplifies the small audio signal and make it proper to be played back with the built-in
speaker.
- Codec IC
CODEC IC is a single powered(+3VDC) device and has the built-in low pass filter with the
frequency response characteristics of 300 to 3400Hz.
This device is used for conversion of AD(Analog to Digital) or DA(Digital to Analog). During the
record, the signal from the Mic. amp. is digitized by this device and then sent to DSP for
compression. Decompression is done by its reverse order process, that is, DSP decompresses the
data and sends them to CODEC. CODEC receives the data from DSP and make it analog signal.
When playing back, this analog signal from the CODEC is amplified by the speaker amp.
and the speaker will sound.