HT9201A

www.DataSheet4U.com HT9201A/B Simple Tone Dialer Features Patent Number: 113235(R.O.C.), 5424740(U.S.A.) Operating voltage: 2.0V~5.5V Low standby current 4×4 keyboard matrix 3.58MHz crystal or ceramic resonator Four flash key times selectable for the HT9201B General Description The HT9201A/B tone dialers are CMOS LSIs designed for telecommunication systems. The HT9201A is for mute output whereas the HT9201B is for flash output. Both dialers provide good performance for regular DTMF dialing with low distortion output and minimal external components. Selection Table Function Item HT9201A HT9201B √ — √ √ F1,F2,F3,F4 MUT E XM UT E Fla sh T im e (m s) — 600/ 300/ 200/ 90 A,B,C,D DT M FO utput √ — Package 16 DIP 16 DIP Pin Assignment 1 3rd Dec ’97 HT9201A/B Keyboard Information Block Diagram Pin Description Pin Name I/O Internal Connection Description These pins form a 4×4 keyboard matrix which can perform keyboard input detection and dialing specification setting functions. When the chip is in the standby mode the column group (C1~C4) remains low whereas the row group (R1~R4) is set high for key input detection. An inexpensive single contact 4×4 keyboard can be used as an input device. Pressing a key connects a single column to a single row, and actuates the system oscillator which result in a dialing signal output. If more than two keys are pressed at a time, no response occurs. The key-in debounce time is 20ms. Refer to the keyboard information for keyboard...