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Functional Block Diagram

Figure 2 shows the functional block diagram for the APR9301-V2

Figure 2 APR9301-V2 Functional Block Diagram

Sample Application

Figure 3 shows the diagram for a single, 20-second message

recording and playback application using theAPR9301

device. When pins are connected as shown in this example,

the operating modes are as follows:

Record Mode (Level-Activated)

A single voice message of up to 20 seconds can be recorded.

The /LED pin will go low during the actual recording process

to provide a visual indication if an LED light is connected to

this pin. The chip is in record mode as long as the /RecL pin

stays low (level-activated). If the message lasts longer than

20 seconds, recording will terminate automatically after the

last available memory cell is written. If the message is shorter

than 20 seconds, the recording operation will stop when the

the /RecL pin goes high. The speaker driver is automatically

tristated during the recording operation.

Messages of up to 30 seconds can be recorded by using

different OscR resistor values (see Table 1).

Playback Mode (Edge-Activated)

Playback always starts from the beginning of the message.

The chip is in playback mode after the /PlayE pin pulses low

(edge-activated). Playback will stop immediately when the

/PlayE pin pulses low a second time. If the newly recorded

message is shorter than the previously recorded message,

the remaining portion of the previous message will not be

played after the new message is played back. The input pre-

amplifier, AGC, and main amplifier circuits are disabled

during playback.

Standby Mode (/CE = "0")

The chip will automatically return to the standby state after

recording or playback operation is completed.

Power Down Mode (/CE = "1")

The chip is always in standby state. No recording or playback

is allowed. Current consumption is typically less than 1

AnaIn

Power Supplies

Amp

AGC

MicRef

MicIn

OscR

SP+

/LED

Amp

SP-

A u to m atic G ain

Pre-

Amp

/RecL /PlayE

C ontrol (A G C )

S amp le & H o ld

S w itch ed

C apacitor F ilter

A n alo g W rite &

R ead C ircuits

N o n -Vo latile

A nalog S torage

M em ory A rray

Device Control

S w itch ed

C apacitor F ilter

Circuit

AnaOut

In tern al

O scillator

APLUS

APR9301-V2