MV5089

MV5089 MV5089 DTMF GENERATOR The MV5089 is fabricated using Plessey Semiconductors' ISO-CMOS high density technology and offers low power and wide voltage operation. An inexpensive 3.58MHz TV crystal completes the reference oscillator. From this frequency are derived 8 different sinusoidal frequencies which, when appropriately mixed, provide Dual-Tone MultiFrequency (DTMF) tones. Inputs are compatible with a standard 2-of-8 active-low keyboard and the keyboard entries determine the correct division of the reference frequency by the row and column counters. D-to-A conversion, using R-2R ladder networks, results in a 'staircase' approximation of a sinewave with low total distortion. Frequency stability over operating voltage and temperature range are maintained within industry DTMF standards. FEATURES Pin-far-Pin Replacement for MK5089 Low Standby Power Minimum External Parts Count 2.75V to 10V. Operation 2-of-8 Keyboard Input High Accuracy Tones Provided by 3.58MHz Crystal Oscillator Pin-Selectable Inhibit of Single Tone Generation Fig.1 Pin connections - top view APPLICATIONS DTMF Signalling for Telephone Sets Mobile Radio Remote Control Point of Sale and Banking Terminals Process Control DP16 ROW INPUTS 34 SINGLE TONE INHIBIT ~:Co-+"""---l r------, TONE OUT KEYBOARD LOGIC ----l '----;--06~~fBLE ' -_ _ _ _+-o()~~~EY 34 <iiW INPUTS Fig.2 Functional block diagram 119 MV5089 ABSOLUTE MAXIMUM RATINGS Voo-VSS Voltage on any pin Current on ...