Overview

The LA4168M is a record/playback system IC for microcassette and compact cassette recorders. The LA4168M is an extremely high-functionality IC that includes a motor control governor circuit, a voice sensor circuit that detects sounds and turns motor on or off, a power switch control circuit that receives an electrical signal from a photosensor and turns all of the IC function blocks on or off, and a circuit that increases the speed of the motor during playback.

Features

• Includes a voice switch that can turn the governor on or off.

• Includes a power switch circuit that can turn all the IC function blocks on or off from a photosensor signal. During record, the IC can automatically turn the governor on or off according to the microphone input level, and furthermore, the governor on/off level can be continuously adjusted from an external control knob. (The control used for volume adjustment during playback.)

• Continuously variable microphone monitor level.

• Includes a drive pin for an LED that lights only when the governor is on in record mode.

Functions

• Microphone and playback preamplifiers

• Record amplifier

• Power amplifier (BTL, 4 Ω)

• Automatic stop circuit (power switch)

• Governor circuit

• Motor speed and high-speed switching circuit

• Microphone power supply

• LED drive circuit

• Voice sensor circuit