CF1155 Datasheet, PDF (3/7 Pages) Nippon Precision Circuits Inc – Melody LSIs

CF1155 series
FUNCTIONAL DESCRIPTION
Melody Modes
The CF1155 series melody mode is determined by the bonding options and levels on the mode control inputs
OSH and LH. When either OSH or LH or both go HIGH (V_DD), the corresponding melody mode is selected as
shown in the following table.
OSH
HIGH
LOW
HIGH
LOW
LH
HIGH
HIGH
LOW
LOW
Melody mode
Level hold 1
Level hold 2
One-shot
Non-play
Level hold 1
When both OSH and LH go HIGH, melody play starts and continues while both are held HIGH. When both
inputs go open circuit or LOW, melody play stops, even if during mid melody.
Note that both OSH and LH inputs should be switched simultaneously using a single switch. If there is timing
difference between the two inputs, then LH has priority.
OSH
LH
OUT
Oscillator
1 TUNE
REPEAT
REPEAT
Pull-down resistance 135kΩ
(2-pin parallel resistance)
500kΩ
135kΩ
NIPPON PRECISION CIRCUITS—3