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ML2502

ML2502 Data Sheet (Revision 8.0)

ML2502 DATA SHEET

Preliminary

RECORD/PLAYBACK LSI with
128Kbit Analog Cell Storage Flash Memory

Revision 8.0 Apr. 01, 1999

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.

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

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ML2502

ML2502 Data Sheet (Revision 8.0)

BLOCK DIAGRAM

PIN LAYOUT

PKG Code: SSOP30-P-56-0.65

Internal

Oscillator

Controller

Address Decoder

128K Bit Cell

Analog Storage Flash

Memory Array

Analog Write & Read Circuits

Power

Supplies

LPF

DGND

PLAY2 ERASE

MON

ROSC

LIN

LOUT

AGND

AOUT

MOUT

AGC

Sampling

Clock

SAM1

SAM2

PLAY1

REC1

REC2

MIN

SPIN

SPOUT+
SPOUT-

DVDD

REC1

REC2

PLAY1

PLAY2

ERASE

MIN

MOUT

LIN

LOUT

AVDD

SPOUT+

SAM1

SAM2

ROSC

DGND

MON

TEST

AOUT

SPIN

AGND

SPOUT-

AGND

(TOP VIEW)

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ML2502

ML2502 Data Sheet (Revision 8.0)

PIN DESCRIPTION

REC1

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

I/O

Description

REC2

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.

PLAY1

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.

PLAY2

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

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.

SAM1
SAM2

Pins used to select a sampling frequency.

SAM1

4.0kHz

5.3kHz

6.4kHz

Unused

MON

Output "H" level during record or playback operation.

Insert a 30k

resistor between this pin and the DGND pin. The resistor determines the

oscillation frequency for the internal oscillation circuit.

ROSC

MIN

Input to the Microphone amplifier.

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

MOUT

LIN

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

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.

LOUT

AOUT

Output analog signal for playback.

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.

SPIN

Output from the speaker driver. Connect a speaker in-between these pins.
Output two phase-inverted analog signals for playback from the speaker driver.

SPOUT+

SPOUT-

DVDD

Digital power supply pin. Insert a 0.1

F or larger bypass capacitor between this pin and

the DGND pin.

DGND

Digital ground pin.

AVDD

Analog power supply pin. Insert a 0.1

F or larger bypass capacitor between this pin and

the AGND pin.

AGND

Analog ground pin.

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ML2502

ML2502 Data Sheet (Revision 8.0)

Record/Playback Operation

ML2502 has two record/playback modes, Dual-phrase record/playback mode and Single-
phrase 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.

Figure 1.1 Timing Chart for Phrase 1 Recording Operation

Start

Stop

Invalid Input

Stopping Process

Power Down

Powering Up

Recording

Power Down

Powering Down

MON

REC2

REC1

Status

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ML2502

ML2502 Data Sheet (Revision 8.0)

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

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.

Figure 1.3 Timing Chart for Phrase 1 Erasing Operation

Start Pulse

Stop Pulse

Power Down

Powering Up

Playing Back

Power Down

Powering Down

MON

PLAY2

PLAY1

Status

Start Pulse

Power Down

Powering Up

Erasing

Power Down

Powering Down

MON

REC1

ERASE

Status

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ML2502

ML2502 Data Sheet (Revision 8.0)

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.

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

Figure 1.5 Timing Chart for Phrase 2 Playback Operation

Start

Stop

Invalid Input

Stopping Process

Power Down

Powering Up

Recording

Power Down

Powering Down

MON

REC2

REC1

Status

Start Pulse

Stop Pulse

Power Down

Powering Up

Playing Back

Power Down

Powering Down

MON

PLAY2

PLAY1

Status

Stop

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ML2502

ML2502 Data Sheet (Revision 8.0)

1.6 Phrase 2 Erasing Operation

(1)

While inputting "H" level to the ERASE pin, input a "H" pulse to the REC2 pin to start erasing
Phrase 2.

(2)

After Phrase 2 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 2 by recording "Silence" from the center
address as far as to address 250. Therefore, if you attempt to playback the erased
phrase, the playback starts at the center address of the memory and ends at address 250.

Figure 1.6 Timing Chart for Phrase 2 Erasing Operation

Start Pulse

Power Down

Powering Up

Erasing

Power Down

Powering Down

MON

REC2

ERASE

Status

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ML2502

ML2502 Data Sheet (Revision 8.0)

2. Single-phrase Record/Playback Mode

2.1 Recording Operation

(1)

In this mode the REC1 has to be connected with the REC2 pin.

Keep on inputting "H" level to the REC1 and the REC2 pin to power up and start recording
from the top address of the memory. Recording goes on while the REC1 and the REC2 pin
being held at "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 before reaching the last address, bring the REC1 and 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 REC1 and the REC2 is
disregarded.

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

Figure 2.1 Timing Chart for Single-phrase Recording Operation

Start

Stop

Invalid Input

Stopping Process

Power Down

Powering Up

Recording

Power Down

Powering Down

MON

REC2

REC1

Status

PLAY2

PLAY1

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ML2502

ML2502 Data Sheet (Revision 8.0)

2.2 Playing Back Operation

(1)

Input "H" pulses to the PLAY1 and the PLAY2 pins simultaneously 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 the phrase before reaching its last address, input "H" pulses again to the
PLAY1 and the PLAY2 pins simultaneously. 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.

Figure 2.2 Timing Chart for Single-phrase Playback Operation

Start Pulse

Stop Pulse

Invalid Input

Power Down

Powering Up

Playing Back

Power Down

Powering Down

MON

REC2

REC1

Status

PLAY2

PLAY1

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ML2502

ML2502 Data Sheet (Revision 8.0)

2.3 Erasing the Phrase 2

(1)

While inputting "H" level to the ERASE pin, input "H" pulses to the REC1 and REC2 pins
simultaneously to start erasing the phrase.

(2)

After the phrase 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 by recording "Silence" from the top address as far as 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.

Figure 2.3 Timing Chart for Single-phrase Erasing Operation

Start Pulse

Power Down

Powering Up

Erasing

Power Down

Powering Down

MON

REC1

ERASE

Status

REC2

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ML2502

ML2502 Data Sheet (Revision 8.0)

3. Repeating Playback Operation

(1)

To repeat playback of the same phrase, keep on inputting "H" level to the PLAY1 or PLAY2
pin. "H" level input to the PLAY1 or PLAY2 causes the LSI to power up and start playback.

(2)

The LSI automatically restarts playback when the last address of the phrase has been
reached.

(3)

When the playback reaches to the last address of the phrase, with the PLAY1 or PLAY2 pin
being held "L" level, the LSI automatically ends playback.

(4)

The LSI automatically powers down after playback ends.

(5)

To stop playback before repetitive playback session ends, bring the PLAY1 or PLAY2 pin
down to "L" level once, and then re-input a "H" pulse to the PLAY1 or PLAY2 pin. The LSI
automatically shifts to low-power consumption mode after playback stops.

Figure 3.1 Timing Chart for Repetitive Playback Operation

Start Pulse

Stop Pulse

Power Down Powering Up

Playing Back

Power Down

Powering Down

MON

PLAY2

PLAY1

Status

Interval

Playing Back

End Playing

Resume Plaing

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ML2502

ML2502 Data Sheet (Revision 8.0)

ABSOLUTE MAXIMUM RATINGS

RECOMMENDED OPERATING RANGES

ELECTRICAL CHARACTERISTICS

DC Characteristics

Note:

1. Applicable only to those input pins without a pull-down resistor.
2. Applicable only to those input pins with a pull-down resistor. (REC1, REC2, PLAY1,
PLAY2, ERASE pins)

Parameter

Symbol

Conditions

Unit

DGND=AGND=0V

°C

Range

Power Supply Voltage

Operating Temperature

2.7 ~ 3.3

-10 ~ + 70

Parameter

Symbol

Conditions

Unit

STG

Ta = 25°C

°C

Rating

Power Supply Voltage

Storage Temperature

-0.3 ~ +6.0

-0.3 ~ V

+ 0.3

Input Voltage

-55 ~ +150

Parameter

Symbol

Conditions

Unit

Max.

Typ.

Min.

DGND=AGND=0V

"L" Input Voltage

"H" Input Voltage

0.45

TBD

0.8 X

-10

=40

µA

=2mA

SPOUT Output

No Load

=0V

=AV

=2.7V ~ 3.3V,DGND=AGND=0V,Ta= -10 ~ +70°C

"L" Output Voltage

"H" Output Voltage

"L" Input Current *

"H" Input Current *

Operating Current

Consumption

Powerdown Current

Consumption

IH1

IL1

DDS1

µA

0.2 X V

- 0.3

µA

100

"L" Input Current *

"H" Input Current *

IH2

IL2

DDS2

Ta= -10 ~ +50°C

Ta= +50 ~ +70°C

µA

100

=0V

=3.0V

-10

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ML2502

ML2502 Data Sheet (Revision 8.0)

AC Characteristics

Note:

*1. In proportion to sampling frequency.

Parameter

Symbol

Unit

Max.

Typ.

Min.

POR

Min. "H" Pulse Width for Record-Start Input

Power-on Reset Time

15.8

=AV

=2.7V ~ 3.3V,DGND=AGND=0V,Ta= -10 ~ +70°C

W RECST

256

µs

279

Min. "L" Pulse Width for Record-Stop Input

Setup Time for Erase Input - REC1, REC2 Input

Min. Pulse Width for Erase-Start Input to REC1,REC2

Min. Pulse Width for Playback-Start Input

Min. Pulse Width for Playback-Stop Input

Powering Up Time 1 (at Erasing)

Powering Up Time 2

Max. Record/Playback Time Length (2-phrase mode) *1

Max. Record/Playback Time Length (1-phrase mode) *1

Erase Execution Time *1

Max. Time for MON to Fall Down at Stop Recording*1

Powering Down Time

16.5

10.5

15.6

256

15.6

15.4

252

14.8

9.5

At fsamp = 6.4 kHz

W RECSP

W PLYST

W PLYSP

WERSST

WERSS

W ERSH

WS1

WS12

W S3

W S4

WRP2

WRP1

W E

Hold Time for Erase Input - REC1, REC2 Input

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ML2502

ML2502 Data Sheet (Revision 8.0)

Analog Circuit Characteristics

Parameter

Symbol

Conditions

Unit

Max.

Typ.

Min.

MIN

MIN Input Resistance

7.8

1.45

±125

V/V

WS12 and

WS4

No Signal Playback

=AV

=2.7V ~ 3.3V,DGND=AGND=0V,Ta= -10 ~ +70°C

MOTP

VDD-0.25

±0.3

= 10mA

0.95

200

LOTP

AOTP

1.35

1.25

Output Voltage from MOUT, LOUT,

AOUT on Powering Up and Powering

Down

4.2

LIN Input Impedance

Line Amp. Open-loop Gain

Mic. Amp. Voltage Gain Control Range

= 0~4kHz

IOP

MIC

OLINE

Output Voltage from SPOUT +/-

on Powering Up and Powering Down

MOUT- LOUT Load Resistance

SPOUT+ / SPOUT-

Amplifier Open-loop Gain

SPOUT+/SPOUT- Voltage Gain

SPOUT +/- Output "H" Voltage

SPIN Input Impedance

SPOUT +/- Output "L" Voltage

SPOUT Output Load Impedance

SPOUT Output Offset Voltage

SPOUT Load Current at Peak Output

= 0~4kHz

1/2 VDD

+0.1

1/2 VDD

-0.1

= 10mA

0.25

1.05

V/V

SPOTP

SNOTP

OOP

OSP

SPC

ISP

SPH

SPL

OFF

SPC

SPO

WS12 and

WS4

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ML2502

ML2502 Data Sheet (Revision 8.0)

TIMING CHARTS

Digital Circuit Section

Powering Up

Start Recording Phrase 1

End Recording Phrase 1 (Recording reaches to the last address)

2.5V

VDD

Internal

Reset Signal

Status

Unstable State

Reseting

Power Down State

POR

Switch Input Allowed

Power Down State

Powering Up Time

Recording

MON

REC2

REC1

Status

WRECST

WS12

W RP1,tWRP2

Powering Down

Power Down State

Recording

MON

REC2

REC1

Status

WS4

WRP1,

WRP2

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ML2502

ML2502 Data Sheet (Revision 8.0)

Stop Recording Phrase 1 (Recording stopped before the last address)

Start Playback Phrase 1

End Playback Phrase 1 (Playback reaches to the last address)

Power Down State

Powering Up Time

Playing Back

MON

PLAY2

PLAY1

Status

W PLYST

WS12

WRP1,

W RP2

Powering Down

Power Down State

Playing Back

MON

PLAY2

PLAY1

Status

WS4

WRP1,

W RP2

Post-Recording Process

Power Down State

Recording

MON

REC2

REC1

Status

WS3

Powering Down

WS4

W RECSP

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