SM1350ADJM View Datasheet(PDF) - Nippon Precision Circuits

Part Name

Description

Manufacturer

SM1350ADJM

High Tone Quality Melody IC

Nippon Precision Circuits  

SM1350ADJM

Melody Output Circuit

The volume control circuit comprises a P-channel current-summing D/A converter, a built-in constant-current source

and an external variable resistor.

Output circuit (A-class)

The A-class output circuit comprises a single 10-bit D/A converter with current output on SP. The D/A converter is set

ON immediately after the oscillator starts, and the current output that results is the center point above and below which

the converter current output varies in response to the waveform amplitude. The SP output is current-to-voltage

converted for connection to audio equipment or amplifiers. The 4 sound generator waveforms are time multiplexed, so

an integrating circuit must be connected between SP and the amplifier to recover the signal.

VDD

VDD

BUSYN

SP

VSS VOL

AMP

SPEAKER

VSS

Figure 4. Output circuit (A-class)

Pin Functions

STN pin

Melody start signal. Melody starts when LOW is detected.

One-shot melody output (LH=LOW)

One-shot melody is a melody control that stops melody after it play to the last of the melody when there is a start trigger.

When STN goes LOW during melody output, the melody specified with S0 to S3 is played

STN

S0 to S3

#N

#M

Melody Output

(SP pin)

#N

#M

Figure 5. One-shot mode

One-shot mode repeat function

In one-shot melody mode, the output repeats the same melody while STN is LOW. When STN goes HIGH, the output

continues until the end of the currently playing melody and then stops.

STN

Melody Output

(SP pin)

#N

#N

#N

Figure 6. One-shot melody repeat timing

SEIKO NPC CORPORATION - 9

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