DESCRIPTION

TDK Semiconductor’s 75T2089/2090/2091 are complete Dual-Tone Multifrequency (DTMF) Transceivers that can both generate and detect all 16 DTMF tone-pairs. These ICs integrate the performance-proven 75T202 DTMF receiver with a DTMF generator circuit.

FEATURES

· DTMF Generator and Receiver on one-chip

· Call progress detection (2090/2091 only)

· Early detect output (2091 only)

· DTMF Receiver exhibits excellent speech immunity

· Analog input range from -32 to -2 dBm (ref 600W )

· Three-state outputs (4-bit hexadecimal) from DTMF Receiver

· AC coupled, internally biased analog input

· Latched DTMF Generator inputs

· DTMF output typ. -8 dBm (Low Band) and -5.5 dBm (High Band)

· Easy interface for microprocessor dialing

· Uses inexpensive 3.579545 MHz crystal for reference

· Low-power 5 volt CMOS