STK4065

No. 2148—3/9

Test Circuit

Notes for Applying the STK4065

The STK4065 is designed as an amplifier for car use

When this voltage is exceeded, the overvoltage protec-

tor will work to bring the circuit to OFF-state, deliver-

ing no output. The overvoltage protector is so designed

as to work at a voltage of 18V to 28V. The protector

works 100% at 28V. When designing an audio set, such

as home stereo, using a transformer power supply, con-

sider AC line regulation and be careful that 18V must

not be exceeded at the quiescent mode. If 18V is

exceeded, the overvoltage protector will work, generat-

ing an abnormal sound.

(2) Protectors

tectors

The STK4065 contains protectors against output pin-

tively to protect the IC when the power switch is turned

forced to be provided at the normal operation mode

after the power switch is turned ON.

protect the IC against damage when pin-to-pin short

occurs in the assembly process.

short protector shown on page 5 must be connected

externally. The output pin-to-GND short protector

works effectively to protect the IC against damage

when the power switch is turned ON at the output Pin-

to-GND short state and also when output pin-to-GND

short is forced to be provided at the normal operation

mode after the power switch in turned ON.

b) Thermal shutdown

The STK4065 contains thermal protectors.

The thermal protector detects abnormal temperature

rise caused when the IC operates abnormally (load

short, etc.), limits the input signal, and prevents tem-

perature from rising, preventing the IC from breaking

down in a short time. The thermal protector starts

working at approximately 135

°C of substrate tempera-

ture Tc and turns OFF the input signal at approxi-

mately 175

°C.