Outline
This IC was developed for use in multifunctional telephones with security features; it has the following functions.

FEATUREs
1. Incorporates efficient switching regulator with broad input voltage range
   VOUT 5V±0.25 IL 250mA (13~45V)
   VIN 15~45V
2. Internal data transmission/reception circuits
   Data can be superposed on the power supply line for transmission.
   Can be switched between two different input modes
3. Internal system reset circuit
   5V line abnormal voltage detection circuit
   Watchdog timer reset circuit
4. Internal speaker amp
   260 mW typ. at 8Ω load
   Mute pin
5. Internal beep sound generator circuit
   With pin to vary audio volume (also used to turn beep sound on and off)