Holtek Semiconductor
Simple Tone Dialer
Holtek Semiconductor
1-memory/2-memory tone/pulse dialer
Holtek Semiconductor
1-Memory/2-Memory Tone/Pulse Dialer
Holtek Semiconductor
12-Memory Tone/Pulse Dialer
Holtek Semiconductor
15-Memory Tone/Pulse Dialer
Holtek Semiconductor
DTMF Receiver
Holtek Semiconductor
22-Memory Tone/Pulse Dialer