MV5087

MV5087 MV5087 DTMF GENERATOR DS3125-2.0 June 1993 The MV5087 is fabricated using 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 Multi-Frequency (DTMF) tones. Inputs are compatible with either a standard 2-of-8 or a single contact (form A) keyboard. 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 and amplitude stability over operating voltage and temperature range are maintained within industry specifications. FEATURES s Pin-for-Pin Replacement for MK5087 s Low Standby Power s Minimum External Parts Count s 3.5V to 10V Operatlon s 2-of-8 Keyboard or Calculator-Type Single Contact (Form A) Keyboard Input s On-Chip Regulation of Output Tone s Mute and Transmitter Drivers On-Chip s High Accuracy Tones Provided by 3.58MHz Crystal Oscillator s Pin-Selectable Inhibit of Single Tone Generation +VDD 1 XMITR 2 COLUMN 1 3 COLUMN 2 4 COLUMN3 5 VSS 6 OSC IN 7 OSC OUT 8 16 TONE OUT 15 SINGLE TONE INHIBIT 14 ROW 1 13 ROW 2 12 ROW 3 11 ROW 4 10 MUTE 9 COLUMN 4 DP16 MP16 Figure 1: Pin connections - top view APPLICATIONS DTMF Signalling for s Telephone Sets s Mobile Radio s...