OKI ML2502 Datasheet

OKI ML2502

ML2502 DATA SHEET Preliminary

RECORD/PLAYBACK LSI with 128Kbit Analog Cell Storage Flash Memory Revision 8.0 Apr. 01, 1999

n GENERAL DESCRIPTION

ML2502 is a record/playback LSI that stores analog signal directly into on-chip Flash memory (128Kbit Cell) without digital conversion utilizing new Analog Storage technology. Such unique features as low voltage operability (2.7 ~ 3.3V), no backup requirement and no external MCU requirement makes the ML2502 an ideal choice for handy Voice Memo, Message Card, toys and other consumer applications.

n FEATURES

• On-chip 128Kbit Cell Analog Storage Flash Memory

Program/Erase Cycles 10K cycles Data Retention Period 10 years

• Record/Playback Control via Switch Input

• Phrasing Mode Single-phrase or Dual-phrase

• Record/Playback Time Length (At 6.4 kHz sampling frequency)

In Dual-phrase Mode Max. ap. 10 sec each (Entire memory area divided into 2) In Single-phrase Mode Max. ap. 20sec (Using the whole memory area by wiring

REC1 and REC2 pins, PLAY1 and PLAY2 pins together)

• Sampling Frequencies

Selectable from 4.0 kHz, 5.3 kHz, 6.4 kHz

• Built-in Mic. Amplifier with AGC (Auto Gain Control)

• Built-in LPF (Low Pass Filter)

• Built-in Speaker Driver

Allows to use either Piezo or Dynamic speaker by externally setting up an amplitude ratio.

• On-chip Oscillation Circuit (No requirement for an external oscillator)

• Operating Voltage 2.7V ~ 3.3V

• Operating Temperature -10°C ~ +70°C

• Packaging 30-pin SSOP, Die Form

ML2502 Data Sheet (Revision 8.0)

OKI ML2502

LIN

LOUT

MOUT

n BLOCK DIAGRAM

MIN

ROSC

SAM1 SAM2

n PIN LAYOUT

PKG Code: SSOP30-P-56-0.65

Internal

Oscillator

Sampling

Clock

AGC

PLAY1REC1 REC2

LPF

Analog Write & Read Circuits

128K Bit Cell

Analog Storage Flash

Memory Array

Address Decoder

Controller

Power

Supplies

DVDD DGNDPLAY2 ERASE MON

AOUT

SPIN SPOUT+

SPOUT-

AV AGND

DVDD

REC1

REC2 PLAY1 PLAY2

ERASE

MIN

MOUT

LIN

LOUT

AVDD AVDD

SPOUT+

(TOP VIEW)

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15

ML2502 Data Sheet (Revision 8.0)

30 29 28 27 26 25 24 23 22 21 20 19 18 17 16

NC SAM1 SAM2 ROSC DGND MON TEST NC NC AOUT SPIN AGND SPOUTAGND NC

OKI ML2502

n PIN DESCRIPTION

PIN I/O Description

Input start-recording signal for Phrase 1 to this pin.

REC1 I

REC2 I

PLAY1 I

PLAY2 I

ERASE I

SAM1 SAM2

"H" level input to this pin initiates recording to Phrase 1 memory area. Recording goes on while this pin being held "H". In single-phrase mode, the pin is connected to the REC2 pin. The REC1 pin is internally pulled down.

Input start-recording signal for Phrase 2 to this pin. "H" level input to this pin initiates recording to Phrase 2 memory area. Recording goes on while this pin being held "H". In single phrase mode, the pin is connected to the REC1 pin. The REC2 pin is internally pulled down.

Input start-playback signal for Phrase 1 to this pin. A "H" pulse input to this pin initiates playback of Phrase 1. Re-inputting a "H" pulse during playback causes to stop playback. In single phrase mode, the pin is connected to the PLAY2 pin. The pin is internally pulled down.

Input start-playback signal for Phrase 2 to this pin. A "H" pulse input to this pin initiates playback of Phrase 2. Re-inputting a "H" pulse during playback causes to stop playback. In single phrase mode, the pin is connected to the PLAY1 pin. The pin is internally pulled down.

Erase-enable signal input pin, used together with the REC1 and/or REC2. Input "H" level to the REC1/REC2 pin with this pin being held "H" to erase respective phrase. The pin is internally pulled down.

Pins used to select a sampling frequency.

SAM1 SAM1

L L

4.0kHz

5.3kHz

6.4kHz

H H

Unused

MON O Output "H" level during record or playback operation.

ROSC I

MIN I Input to the Microphone amplifier.

MOUT O

LIN I Input to the Line amplifier. Connected to inverted input for the internal Op. amplifier.

LOUT O

AOUT O Output analog signal for playback.

SPIN I

SPOUT+

SPOUT-

DVDD DGND AVDD AGND

Insert a 30kΩ resistor between this pin and the DGND pin. The resistor determines the oscillation frequency for the internal oscillation circuit.

Output from the Microphone amplifier. Voltage amplitude is automatically controlled to an appropriate output level by the internal AGC circuit.

Output from the Line amplifier. Connected to the output pin from the internal Op. amplifier. Connecting resistors to the LIN and LOUT pins configures an inverted amplifier.

Input to the speaker driver. The resistor's value inserted between the AOUT and SPIN pin determines voltage amplitude of the speaker driver. Select an appropriate value depending on types of speaker in use.

Output from the speaker driver. Connect a speaker in-between these pins.

Output two phase-inverted analog signals for playback from the speaker driver. Digital power supply pin. Insert a 0.1µF or larger bypass capacitor between this pin and

−

the DGND pin.

−

Digital ground pin. Analog power supply pin. Insert a 0.1µF or larger bypass capacitor between this pin and

−

the AGND pin.

−

Analog ground pin.

ML2502 Data Sheet (Revision 8.0)

OKI ML2502

n Record/Playback Operation

ML2502 has two record/playback modes, Dual-phrase record/playback mode and Singlephrase record/playback mode. While in Dual-phrase record/playback mode the total memory space is divided evenly into two areas for 2-phrase record/playback, the entire memory space is used for one phrase record/playback in Single-phrase record/playback mode.

In Dual-phrase record/playback mode the first half of the memory, i.e. from the top address up to the center address, is assigned to Phrase 1, and the second half, i.e. from the center address to the last address, is assigned to Phrase 2. Record/playback of Phrase 1 can be controlled via the REC1 and PLAY1 pins, while Phrase 2 can be controlled via the REC2 and PLAY2 pins respectively.

In Single-phrase mode record/playback must be performed with the REC1 being connected to the REC2 pin and the PLAY1 being connected to the PLAY2 pin respectively. In both playback modes repetitive playback function for the same phrase is available.

1. Dual-Phrase Record/Playback Mode

1.1 Phrase 1 Recording Operation

(1) Keep on inputting “H” level to the REC1 pin to power up and start recording from the top

address of the memory. Recording goes on while the REC1 pin being held “H” level. (2) The LSI automatically ends recording when the center address has been reached. (3) The LSI automatically shifts to low-power consumption mode after recording ends. (4) To stop recording for phrase 1 before reaching the center address, bring the REC1 pin

down to “L” level. The LSI automatically shifts to low-power consumption mode after

recording stops. (5) During recording operation any signal input to other pins than the REC1 is disregarded.

Note: Re-recording always causes to overwrite the existing recording data for a given phrase.

Start StopInvalid Input

REC1

REC2

MON

Status

Power Down Powering Up Recording Power DownPowering Down

Stopping Process

Figure 1.1 Timing Chart for Phrase 1 Recording Operation

ML2502 Data Sheet (Revision 8.0)

OKI ML2502

1.2 Phrase 1 Playback Operation

(1) Input a “H” pulse to the PLAY1 pin to power up and start playback from the top address of the

memory.

(2) The LSI automatically ends playback when the last address of the recorded phrase has been

reached. (3) The LSI automatically shifts to low-power consumption mode after playback ends. (4) To stop playback of phrase 1 before reaching the last address, input a “H” pulse again to

the PLAY1 or PLAY2 pin. This will cause the LSI to stop playback and then automatically

shift to low-power consumption mode. (5) During playback operation signal input to the PLAY1 or PLAY2 pin only is valid, any other

signal input is disregarded

Start Pulse Stop Pulse

PLAY1

PLAY2

MON

Status

Power Down Powering Up Playing Back Power DownPowering Down

Figure 1.2 Timing Chart for Phrase 1 Playback Operation

1.3 Phrase 1 Erasing Operation

(1) While inputting “H” level to the ERASE pin, input a “H” pulse to the REC1 pin to start erasing

Phrase 1. (2) After Phrase 1 having been erased, the LSI automatically shifts to power-down mode for

low-power consumption.

Note: Erasing operation cannot be abandoned in the middle once getting started.

Internally, the LSI performs erasing Phrase 1 by recording “Silence” from the top address to address 250. Therefore, if you attempt to playback the erased phrase, the playback starts at the top address of the memory and ends at address 250.

Start Pulse

ERASE

REC1

MON

Status

Power Down Powering Up Erasing Power DownPowering Down

Figure 1.3 Timing Chart for Phrase 1 Erasing Operation

ML2502 Data Sheet (Revision 8.0)

OKI ML2502

1.4 Phrase 2 Recording Operation

(1) Keep on inputting “H” level to the REC2 pin to power up and start recording from the top

address of the memory. Recording goes on while the REC2 pin being held “H” level. (2) The LSI automatically ends recording when the last address of the memory has been

reached. (3) The LSI automatically shifts to low-power consumption mode after recording ends. (4) To stop recording for Phrase 2 before reaching the last address, bring the REC2 pin down

to “L” level. The LSI automatically shifts to low-power consumption mode after recording

stops. (5) During recording operation any signal input to other pins than the REC2 is disregarded.

Note: Re-recording always causes to overwrite the existing recording data for a given phrase.

Start StopInvalid Input

REC1

REC2

MON

Status

Power Down Powering Up Recording Power DownPowering Down

Stopping Process

Figure 1.4 Timing Chart for Phrase 2 Recording Operation

1.5 Phrase 2 Playback Operation

(1) Input a “H” pulse to the PLAY2 pin to power up and start playback from the center address of

the memory. (2) The LSI automatically ends playback when the last address of the recorded phrase has been

reached. (3) The LSI automatically shifts to low-power consumption mode after playback ends. (4) To stop playback of Phrase 2 before reaching its last address, input a “H” pulse again to the

PLAY1 or PLAY2 pin. This will cause the LSI to stop playback and then automatically shift

to low-power consumption mode. (5) During playback operation signal input to the PLAY1 or PLAY2 pin only is valid, any other

signal input is disregarded

Start Pulse Stop Pulse

PLAY1

PLAY2

Stop

MON

Status

Power Down Powering Up Playing Back Power DownPowering Down

Figure 1.5 Timing Chart for Phrase 2 Playback Operation

ML2502 Data Sheet (Revision 8.0)

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