LC72701M

CMOS LSI No. 5561 LC73701M Serial Interface Dialler Overview The LC73701M is a DTMP/pulse output dual-system dialer CMOS LSI for use in push-button telephones. It provides an on-chip serial interface and operates under the control of data sent over that serial interface. The LC73701M can be easily controlled by the system CPU using this dedicated interface. The dial pulse make ratio can be specified to be either 33 or 39%. Wide operating voltage range Pulse mode: VDD = 1.5 to 5.5 V DTMF mode: VDD = 2.0 to 5.5 V Package Dimensions unit: mm 3095-MFP18 [LC73701M] Functions Functions as a dialer that is controlled over a serial interface. The built-in oscillator circuit (fOSC = 4.19 MHz) can use either a crystal oscillator or a ceramic resonator as its oscillator element. The adoption of a high-precision (±0.04%) DTMF signal frequency divider circuit allows a ceramic resonator to be used as the oscillator element. The buffer memory can store up to 32 digits of 5-bit data. Mode change and pause commands can also be stored as data in the buffer memory. Pauses can be inserted automatically on mode changes (auto-pause). A pause can be cancelled during that pause. The mode change function supports changing from pulse to tone (single direction). Generates all 16 DTMF signals. The pulse dialer output can be turned on or off arbitrarily. The pulse dialer output circuit can be selected to be either an n-channel open drain or a complementary circuit. The pu...