STK4067 Просмотр технического описания (PDF) - SANYO -> Panasonic
Номер в каталоге
Компоненты Описание
производитель
STK4067 Datasheet PDF : 8 Pages
| |||
STK4067
STK4067 Design Data
(1) The Protection Circuits
a) Overvoltage Protector
Since the STK4067 is designed for car stereo applications, VCC max for operating mode is set to 18 V.
Exceeding the VCC maximum level activates the overvoltage protector and the circuit switches to an off-state and
delivers no output. The overvoltage protection circuit is set for a functional range from 18 to 28 V; 100%
operation at 28 V. For this reason, you should be careful not to exceed the 18 V limit in quiescent mode and keep
in mind AC line regulations when setting using a transformer power supply for designs such as home stereo
systems. Exceeding 18 V activates the overvoltage protector and results in the generation of abnormal sounds.
b) Thermal Shutdown
The thermal shutdown protection circuit is designed to first detect abnormal temperature rises which occur during
abnormal operation (such as load shorts) and then prevent damage to the IC by limiting the input signal; thereby
preventing a further rise in the temperature. The thermal shutdown protector is set to activate at substrate
temperature of 135°C with a complete shutdown by switching to an off-state if temperatures rise to 175°C. Under
normal application, the IC is equipped with a heat sink and the temperature never reaches a level resulting in a
complete off-state switch and saturation occurs at a specific temperature. For example, when a short occurs with
an IC mounted 4.5°C/W heat sink, saturation is achieved at approximately 160°C. At this point, Tj exceeds its
maximum rating of 170°C. As previously mentioned, this circuit is designed to protect the IC from damage
sustained in a short period of time and you should note that the protection circuit will not protect the IC if
abnormal temperature rises occur over a long period of time.
(2) Precautions
a) Excessive Input
If a 1 V or greater (f = 1 kHz.rms) overinput is applied to the input pin, the DC balance of the input channel for
the input monolithic amplifier is disrupted and output is cut off. In addition, DC voltage is generated on the
output pins and causes damage to the speakers. Proper caution should be displayed in preventing input above this
voltage.
b) Parasitic Oscillation
The STK4067 performs phase compensation using 2.2Ω and 0.47µF between VCC and the bootstrap pins. Under
such conditions, the power supply line must be in a close proximity to the bootstrap pins for the inverting and
non-inverting amplifiers. If the power line is too long, parasitic oscillation is likely to occur at low temperatures.
If such a problem arises, add a 0.1µF rated condenser between the ground and the head of the power supply line
in order to lower the impedance.
c) Power Supply Voltage Inverse Application
The STK4067 is not equipped with a built-in power supply voltage inversion protection circuit. If the possibility
exists, one should be externally connected.
d) Power Off
Do not connect pin 1 of the VCC pin directly to the ground or else the IC will be damaged. When connecting pin
1, install a resistor rated for 100Ω or greater in series with pin 1, or you may place a diode between pin 10 and pin
1.
(3) Application Circuits
a) The under frequency band may be magnified, for applications using a booster amplifier or woofer driver
amplifier, the bootstrap condensers (C3 and C4) can be changed from 220µF to 470µF. Refer to PO-f graphs.
b) L1 = 3 µH and R3 = 4.7Ω are for anti-oscillation applications against capacity loads. We recommend the use of
this coil and resistor with the most compatible amplifier sets connected to general use speakers. This coil is not
necessary when the load capacity is low using a chosen speaker connected to a radio-cassette player or active
speaker.
No. 4376-3/8
Share Link: 