[GEC PLESSEY SEMI]

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
■ Pin-for-Pin Replacement for MK5087
■ Low Standby Power
■ Minimum External Parts Count
■ 3.5V to 10V Operatlon
■ 2-of-8 Keyboard or Calculator-Type Single Contact (Form A) Keyboard Input
■ On-Chip Regulation of Output Tone
■ Mute and Transmitter Drivers On-Chip
■ High Accuracy Tones Provided by 3.58MHz Crystal Oscillator
■ Pin-Selectable Inhibit of Single Tone Generation

APPLICATIONS
DTMF Signalling for
■ Telephone Sets
■ Mobile Radio
■ Remote Control
■ Point-of-Sale and Banking Terminals
■ Process Control