IN9270

TECHNICAL DATA IN9270 DTMF RECEIVER High-Performance Silicon-Gate CMOS The IN9270 is a complete DTMF receiver integrating both the bandsplit filter and digital decoder functions. The filter section uses switched capacitor techniques for high- and low-group filters and dialtone rejection. Digital counting techniques are employed in the decoder to detect and decode all 16 DTMF tone-pairs into a 4-bit code. External component count is minimized by on-chip provision of a differential input amplifier, clock-oscillator and latched 3-state bus interface. Complete receiver in an 18-pin package. Excellent performance. CMOS, single 5 volt operation. Minimum board area. Central office quality. Low power consumption. ORDERING INFORMATION IN9270N TA = -10° to 70° C PIN ASSIGNMENT LOGIC DIAGRAM * Connect to GND PIN 9 = GND PIN 18 = VCC PINS 5,6 = NO CONNECTION 1 www.DataSheet.in IN9270 PIN DESCRIPTIONS NAME ESt PIN 16 DESCRIPTION Early steering output. Presents a logic high immediately when the digital algorithm detects a recognizable tone-pair (signal condition). Any momentary loss of signal condition will cause ESt to return to a logic low. Gain Select. Gives access to output of front-end differential amplifier for connection of feedback resistor. Internal Connection. Must be tied to GND. Non-Inverting Input Inverting Input Clock Input Clock Output Connections to the front-end differential amplifier. 3.579545 MHz crystal connected between these pins completes intern...