IN5851

( DataSheet : www.DataSheet4U.com ) TECHNICAL DATA IN5851 PULSE DIALER WITH REDIAL The IN5851 is a monolithic CMOS integrated circuit which uses an inexpensive RC oscillator for its frequency reference and provides all the features required for implementing a pulse dialer with 32 digit redial. Wide operating voltage range (2.0~6.0V) Low power dissipation Use either a standard 2 of 7 matrix keyboard with negative true common or the inexpensive form A-type keyboard Make/Break ratio can be selected Redial with * or # Continuous MUTE Power up clear circuitry on chip 10 pps/20 pps can be selected ORDERING INFORMATION IN5851N Plastic TA = -20° to 70° C LOGIC DIAGRAM PIN ASSIGNMENT PIN 1 = VCC PIN 6 = GND www.DataSheet4U.com 1 www.DataSheet4U.com IN5851N PIN DESCRIPTION NAME VCC PIN 1 Positive supply pin. The voltage on this pin is measured relative to Pin 6 and is supplied from a 150µA current source. This voltage should be regulated to less than 6.0 volts using on external form or regulation. VREF 2 The VREF output provides reference voltage that tracks internal parameters of the IN5851N. VREF provides a negative voltage reference to the VCC supply. Its magnitude will be approximately 0.6 volt higher than the minimum operating voltage of each particular IN5851N. The typical application would be to connect the VREF pin to the GND pin (Pin 6). The supply to the VCC pin (Pin 1) should then be regulated to 150µA (IOP max). with this amount of supply current, ...