MC34018P

The MC34018P speaker-phone combined circuit incorporates the necessary functions to produce a high quality han ds-free speaker-phone system. The applications consist of household and office speaker-phones, intercom systems, hand free kit for mobile phones, and so on.

Features of the MC34018P are:(1)all necessary level detection and attenuation controls for a hand-free telephone included;(2)background noise level monitoring with long time constant;(3)background sound level compensation for transmit and receive levels as well as the background level;(4)wide operating dynamic range through signal compr ession;(5)on-chip voltage regulators illuminate external regulators for lining operation;(6)power audio amplifier for typical 100mW output (into 25 ohms)with peak limiting for speaker to minimize distortion;(7)chip select pin for activ e/stand by operation;(8)volume control function for external volume control.

The absolute maximum ratings and electrical characteristics of the MC34018P can be summarized as:(1):V+terminal Voltage (pin 16) +12V and -1.0 V;(2):speaker amplifier ground(pin 14) is +3.0V and-1.0 V;(3):storage temperature ranges from-65°C+150 °C.electrical characteristics:(1):V+supply current is 9.0 mA max when V+is 11V and Pin 18 is 0.7V,V+supply current is 600 uA when V+is 11V and Pin 18 is 1.6V;(2):VCC voltage(V+=7.5V)of regulation(6.5V<V+ <11V) is 6.5 mV typ and 150 mV max;(3):VB voltage(V+=7.5V) is 2.5 Vdc min,2.9 Vdc typ and 3.3 Vdc max;(4):output resistance(IB=1.7mA) is 250ohms typ.