Rainbow Electronics APR9600 - Manual (Page 2)

INTEGRATED CIRCUITS INC.
- APR9600
http://www.aplusinc.com.tw Page / 17 Ver2.1 2
PS : The APR9600 DIP & SOP is not [ PIN TO PIN ]
3 Functional Description :
APR9600 block diagram is included in
order to describe the device's internal
architecture. At the left hand side of the
diagram are the analog inputs. A
differential microphone amplifier, including
integrated AGC, is included on-chip for
applications requiring use.The amplified
microphone signals fed into the device
by connecting the ANA_OUT pin to the
ANA_IN pin through an external DC
blocking capacitor. Recording can be fed
directly into the ANA_IN pin through a DC
blocking capacitor, however, the
connection between ANA_IN and
ANA_OUT is still required for playback.
The next block encountered by the input
signal is the internal anti-aliasing filter.
The filter automatically adjust its response
according to the sampling frequency
selected so Shannon’s Sampling Theorem
is satisfied. After anti-aliasing filtering is
accomplished the signal is ready to be
clocked into the memory array.
This storage is accomplished through a
combination of the
Sample and Hold circuit and the Analog
Write/Read circuit. These circuits are
clocked by either the Internal
Oscillator or an external clock source.
When playback is desired the previously
stored recording is retrieved from memory,
low pass filtered, and amplified as shown
on the right hand side of the diagram. The
signal can be heard by connecting a
speaker to the SP+ and SP- pins.
Chip-wide management is accomplished
through the device control block shown
in the upper right hand corner. Message
management is provided through the
message control block represented in the
lower center of the block diagram.
More detail on actual device application
can be found in the
Sample Application
section. More detail on sampling control
can be found in the
Sample Rate and
Voice Quality section. More detail on
Message management and device
control can be found in the
Message
Management section.