SM8230A

SM8230A NIPPON PRECISION CIRCUITS INC. Tone Dialer with Built-in Piezo Driver PINOUT OVERVIEW The SM8230A is a dual-tone signal generator LSI developed for DTMF (dual tone multi-frequency) dialing. It features a built-in piezo-electric speaker driver for direct connection to a piezo-electric buzzer. The DTMF frequencies can be set to correspond to the DTMF standards of any country. The output level is also adjustable under software control. These features, combined with its small package and low power dissipation, make the SM8230A a very use device to use. SD SCL OE VSS 1 8 VDD BZH BZL 8230AS 4 5 CLK PACKAGE DIMENSIONS FEATURES s s s s s s s 3-line serial interface to external CPU 2 independent, adjustable frequency outputs Piezo driver for direct connection to a piezoelectric buzzer 4 system clock frequencies selectable (480 kHz, 960 kHz, 1.92 MHz, 3.84 MHz) 2.6 to 3.3 V supply voltage Low current consumption 3.0 mA (max) operating current 1 µA (max) standby current 8-pin plastic SOP 4.4 0.2 6.2 0.3 5.2 0.3 0.15− 0.05 + 0.10 0.05 0.05 1.5 0.1 1.27 0.4 0.1 0 10 0.4 0.2 NIPPON PRECISION CIRCUITS—1 SM8230A BLOCK DIAGRAM VDD Programmable Counter High Group ROM D/A Converter Output Control BZH SD SCL OE LATCH SELECTOR CLK VSS Programmable Counter Low Group ROM D/A Converter Output Control BZL PIN DESCRIPTION Number 1 2 3 4 5 6 7 8 Name SD SCL OE VSS CLK BZL BZH VDD I/O I I I – I O O – Serial data input Serial data transfer clock input. (F...