General Description
The HT93214 are dialer series designed for low cost telephone set applications with expandable features such as Lock function, keytone and LCD display interface. With a 44 keyboard, it performs normal tone/pulse switchable dialing, and provides one-key redialing function with a 32-digit memory for speed dialing. An on-chip oscillator is built-in to work with an exter nal 3.58Mhz crystal or ceramic resonator for accurate timing. The HT93214 provides 300ms (F1 key) and 600ms (F2 key) of flash time; Tone dialing and 10pps, 20pps selection with 1/2 M/B ratio for pulse dialing.

Features
Operating Voltage: 2.0V~5.5V
Low standby current
Low memory retention current: 0.1A (Typ.)
Tone/Pulse switchable
32 (pulse)/31 (tone) digits for redialing
Pause and P  T key for PBX
44 keyboard matrix
3.58MHz crystal or ceramic resonator
Hand-free control
Pause, P  T can be saved for redialing
One-key redialing
Keytone output
Pause time: 2.2s
Cascadable manual dialing after redialing
Calibrated DTMF timing for redialing
HT93214A: 16-pin DIP package
HT93214B/AT: 18-pin DIP package