STK6153 RF output amplifier circuit diagram
The internal front level of the STK6153 uses a constant pressure source bias, which can better stably stably operate the working state of the output stage, but the static current that the STK6153 4 foot and the constant voltage bias in the 1 foot can only be 10mA, which is undoubtedly This leads to a certain extent, the amplifier is seriously crossing the distortion and the tapentation. In addition, the final current output area of the STK6153 chip is much larger than the integration of the LM1875, TDA1514, so the internal resistance is smaller, and the power margin is greater. However, the output form of the STK6153 collector opening is increased the output impedance of the amplifier, so that the above advantages cannot be embodied. In response to the above defects, I am not used for the pre-serial bias of STK6153, and the post-stage is changed to the emitter output, and the STK6153 is driven by UPC1225H to carry out a high-quality low-cost Hi-Fi amplifier, and the specific circuit is shown.
UPC1225H is a 50W sound drive circuit introduced by NEC. It has a complete protection link inside the chip. Although the peripheral circuit is slightly complicated, the output voltage deviation of UPC1225H is only ± 5mV, extremely wide power band and extremely high conversion rate make it The sound, soft and more resistant to the integration of integration than LM3886.
The accelerated capacitor C5 in the circuit diagram has a significant effect on the high frequency output of the amplifier, and the capacity should not be too large, and it is best to use the CBB capacitor. T1 is selected from any low frequency power NPN tube. RW1 is the only component that needs to be adjusted in the circuit. By adjusting the RW1 to change the C, the E-element voltage can fine-tune the bias of the power discharge stage output tube. After the circuit is installed under honesty, it is checked to enter the false load, and the RW1 is carefully adjusted by the screwdriver to minimize the output potential of the midpoint. UPC1225H, the temperature rise of STK6153 is relatively high, and a suitable heat sink is needed.
A set of speaker protection circuits composed of UPC1237HA is also designed. D1 uses a germanium diode, and its anode is connected to any of the alternating current output of the transformer secondary, and the relay J1 is powered directly from the 24V voltage supplied by the LM7824.
Practice has proved that STK6153 and UPC12225H uses the advantages of both, not only retains better low frequency strength and F dive depth, but the elasty of amplifiers, high-frequency solubility is more obvious than the amplifier made of STK6153 + STK3048A improve.
STK3048 and STK6153 Department of Japanese Sanyo Company thick film amplifier integrated circuit. STK3048 is a front-level voltage amplification integrated circuit; STK6153 is a primary current amplification integrated circuit.
STK3048 is a 15-foot dual-channel single-column thick film package, which is connected to (8), but is insulated from the inner circuit. (8) There is a certain shielding effect on the internal circuit after the foot. This thick film does not have to be loaded with a heat exchanger when working.
There are two-stage, input-stage zone-protected differential amplifiers, and two diodes of the differential tube base are protected by two diode amplifiers in the STK3048. The contrast of the collector is a series phase compensation network prevents the input stage from generating transient distortion due to sudden signal. A set of mirrored current sources are connected between the two episode electrodes. The purpose of this circuit is to linearly reverse the right input tube current to form two subgraduated current sources to the left input tube, and perform current excitation on the column. The main voltage amplification is a total co-transmissive circuit, and the signal is widely enlarged, and the direct coupling between the input, the output stage provides impedance matching; the upper tube is linearly outputted the amplification current to reduce the opening of the stage. Lost, and provide greater excitation power for the column. This two-stage magnifying tube is complemented by constant current source, and the power ripple suppression is strong.
STK6153 is a 10-foot single-column single column thick film package (two pieces of double channels), and the inner circuit has been electrically insulated from the exposed radiator. The STK6153 integrates a constant pressure source offset, unsatisfactory push and unstoppable composite current amplification circuit. With full complementary symmetrical structure, high rate, high precision, high power, low noise, and other excellent characteristics. Due to the built-in complex of the constant voltage source, the unlatten high power tube is always in the best working state, which has excellent temperature compensation. The complementary output of the thick film block is designed into an inverted Dolinton composite circuit, and outputs the output impedance in the form of a collector opening.
The power amplifier circuit consisting of STK3048 and STK6153 is shown in Figures 3-41 (power supply, protection circuit), and the inner circuit of the front and rear grade IC in kind. Pre-grade small capacitors can be used in German WIMA or ERO quality capacitors, and the power filter is used for the large electrical solution with Nissan Marcon Nippon, Chemicon Nitsuko, RubyCon brand's capacitance. Each large electrolysis is connected in parallel with WiMa0.1uf ~ 0.33uf. Capacitance to improve frequency characteristics. The circuit does not need to be commissioned, you can work. In the general listening sensation, the frequency bands in the full range look very balanced, dynamic, low frequency, low distortion, fast transient response, purity, and small noise is particularly small. Circuit sinusoidal power; 2X100W, distortion.
The STK3048 and STK6153 internal circuits are simpler, and their sound quality is very good. However, the design of the peripheral route and the choice of peripheral components have a large impact on the sound quality of the IC, and this amplifier uses the circuit shown in Figures 3-42.
1. The GM control volume is used, and the volume potentiometer is connected to the gain control point of IC3 (NE5532), and its negative feedback depth is changed to change the volume size. STK3048 works in the optimal stability. There is almost no sliding noise when adjusting the volume. More importantly, the dynamic range is still constant, and the music details are performed in the big volume, and there is no feeling of water with water.
2. The constant voltage mode is used to drive the load in constant voltage mode in the constant voltage method of constant current, and the transient characteristics of the amplifier are improved, enhance the strength of the bass and the sharpness of the treble.
3. Cancel the loop negative feedback capacitor, IC4 (NE5532) and peripheral components constitute an output midpoint zero servo circuit. Used to servo STK3048 2, (14), which causes the STK6153 output DC potential to cancel the feedback capacitance, and improve the high and low frequency parsing of the amplifier.
The amplifier is subjectively listening: the treble is fine, the middle sound is bright, the bass is full, the zona level is clear, the harmonic distortion is small, the noise is small, the noise is low, the dynamic range is extremely wide. Since the output power is large, pay attention to the power supply to be used, and the STK6153 radiator should not be too small. The op amp IC is powered by a stand-alone active servo power supply. In addition, the amplifier must install the speaker protection circuit, read the full text, the technical area
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