OVERVIEW
The SM1350 series are single-chip high tone quality melody ICs, fabricated using NPC’s Molybdenumgate CMOS process. Melodies are selected in serial or binary (parallel) mode, up to a maximum of 16 melody blocks. There are 4 sound generators incorporated to produce 4 kinds of output tone controlled by 16-tone data, making these ICs ideal for mechanical clocks and similar applications where high tone quality output is demanded.

FEATURES
■ Basic Functions
    • 4.0 MHz oscillator frequency
    • Power-save function
        - Oscillator stopped when no output
        - S0 to S3, MODE, LH pull-up resistors open
    • BTL or A-class outputs
    • Chattering prevention circuit (STN, STOP, S0 to S3)
    • 10-bit D/A converter
■ Sound Generator Functions
    • DWS (dual wave synthesis) sound generators
    • 4 simultaneous sounds for 4 tones
    • G2 to F#7 note range
    • 16-tone programmable
■ Melody Functions
    • Up to 16 programmable melodies (singly or in medleys)
    • 1024-step length (notes, rests, jumps, end codes)
    • Level hold/one-shot melody modes
    • Serial/binary (parallel) select modes
    • 4.8 to 605.6 tempo range in 127 steps
    • 12 rhythm values
    • Ties and slurs programmable
■ Control Signal Outputs
    • BUSYN signal LOW during melody output
    • CT signal output for external control
■ 2.4 to 5.5 V supply voltage
■ Package
    • 24-pin SSOP (SM1350×××)
■ Molybdenum-gate CMOS