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