The article discusses various microcircuits of frame scanning output stages. Many microcircuits have already been discontinued, but are still available in the Dalincom online store and other radio stores.

1. Microcircuits from SANYO

1.1. LA7837, LA7838

LA7837, LA7838 microcircuits can be used as frame scan output stages in TVs and monitors. LA7837 is intended for portable TVs and middle-class TVs, with a maximum current of frame coils of the deflection system of picture tubes of no more than 1.8 A. For TVs with picture tube diagonals of 33…37”, LA7838 is intended with a maximum deflection current of 2.5 A. The microcircuits are produced in a SIP13H package . The location of the microcircuit pins is shown in Fig. 1. The chips include an input trigger, a ramp driver, a size switching circuit, an output amplifier, a flyback boost circuit, and a thermal protection circuit. Structural scheme microcircuits are shown in Fig. 2.

The frame synchronization signal is supplied to the input of the microcircuit trigger (pin 2). At the output of the trigger, pulses are generated, the frequency of which corresponds to the vertical scanning frequency. External circuit connected to pin. 3, determines the initial time of formation of the sawtooth signal. The formation of a sawtooth signal is carried out using an external capacitor connected to the pin. 6. The amplitude of the frame saw signal is changed using a size switching circuit based on an external identification signal with a frequency of 50/60 Hz and using a signal feedback, arriving at the pin. 4. The feedback signal, proportional to the amplitude of the output signal, is removed from an external current-limiting resistor connected in series with the OS frame coils. The generated frame saw signal is sent to the frame scan signal amplifier, while the gain and linearity of the cascade depend on the feedback signal arriving at the pin. 7.

The output stage of the microcircuit directly generates the deflection current (pin 12). To power it, a voltage booster circuit with an external capacitor and a diode is used. During forward stroke, the output stage is powered through an external diode with the voltage supplied to the pin. 8. During the reverse stroke, using the circuit for generating a reverse stroke pulse, in addition to the supply voltage, the voltage stored on the external boost capacitor is added. As a result, approximately double the voltage is applied to the output stage of the microcircuit. In this case, a reverse pulse is formed at the output of the cascade, which exceeds in amplitude the supply voltage of the microcircuit. A pin is used to block the output stage. 10. The characteristics of the microcircuits are given in table. 1.

1.2. LA7845

The LA7845 microcircuit is used as a vertical scan output stage in televisions and monitors with picture tube diagonals of 33…37” and a maximum deflection current of 2.2 A. The microcircuit is produced in a SIP7H package. The location of the microcircuit pins is shown in Fig. 3. The microcircuit includes an output amplifier, a voltage booster circuit for generating a reverse pulse, and a thermal protection circuit. The block diagram of the microcircuit is shown in Fig. 4.

The frame saw signal goes to the frame scan signal amplifier (pin 5). The same pin receives a feedback signal that determines the gain and linearity of the cascade. The reference voltage is supplied to the other input of the amplifier (pin 4). A deflection current is generated at the output of the amplifier (pin 2). To power the output stage of the amplifier during reverse stroke, a voltage boost circuit with an external capacitor and a diode is used. The characteristics of the microcircuit are given in table. 2.

1.3. LA7875N, LA7876N

Chips LA7875N, LA7876N are intended for use in TVs and monitors with high resolution. The microcircuit is produced in SIP10H-D and SIP10H packages, respectively. The location of the microcircuit pins is shown in Fig. 5 and 6. The microcircuits include an output amplifier, two voltage boost circuits and a thermal protection circuit. The maximum output current of the LA7875N microcircuit is 2.2 A, and the LA7876N is 3 A. The block diagram of the microcircuits is shown in Fig. 7.

To reduce the vertical scan return time required to increase resolution, the microcircuit uses two voltage boost circuits. This makes it possible to increase the supply voltage of the output stage during flyback by three times, which correspondingly leads to an increase in the amplitude of the flyback output pulse.

The frame saw signal is supplied to the inverting input of the frame scan signal amplifier (pin 6). The same pin receives a feedback signal. The reference voltage is supplied to the direct input of the amplifier (pin 5). To power the output stage of the amplifier during the reverse stroke, two voltage boost circuits are used, increasing the supply voltage of the output stage three times. The characteristics of the microcircuits are given in table. 3.

1.4. STK792-210

The STK792-210 chip is intended for use as a vertical scanning output stage in high-resolution TVs and monitors. The microcircuit is produced in a SIP14С3 package. The location of the microcircuit pins is shown in Fig. 8. The microcircuit includes an output amplifier, a voltage booster circuit for generating a reverse pulse, a built-in booster circuit diode and a vertical alignment circuit. The block diagram of the microcircuit is shown in Fig. 9.

The frame saw signal is fed through an external amplifier to the frame scan signal amplifier (pin 12). At the input of an external amplifier, this signal is added to a feedback signal, which determines the gain of the entire vertical scanning channel and its linearity. The other input of the external amplifier provides a reference voltage and a local feedback signal. The deviation current is formed at the output of the amplifier (pin 4). To power the output stage of the amplifier during reverse stroke, a voltage boost circuit with a built-in diode and an external capacitor is used (pins 6 and 7). The built-in vertical alignment circuit is used to adjust the alignment. Centering is carried out by changing the potential constant level on pin 2. The characteristics of the microcircuit are given in table. 4.

1.5. STK79315A

The STK79315A chip is intended for use in monitors with increased resolution as a vertical scanning output stage. The microcircuit is produced in a SIP18 package. The location of the microcircuit pins is shown in Fig. 10. The microcircuit includes a frame frequency generator, a sawtooth signal shaper, an output amplifier, a voltage booster circuit for generating a reverse pulse, a built-in booster circuit diode and a vertical alignment circuit. The block diagram of the microcircuit is shown in Fig. eleven.

The TTL level signal is supplied to the synchronization input of the frame frequency generator (pin 18). The external circuit of the generator is connected to the pin. 16. The output signal of the generator enters the sawtooth signal generating circuit. The external capacitor of the driver is connected to the pin. 11. The feedback circuit of the driver, which determines the linearity of the output signal, is connected to the pin. 14. The amplitude of the saw signal is determined by the potential on the pin. 12. From the output of the shaper, the frame saw signal goes to the frame scan signal amplifier. The other input of the amplifier receives a feedback signal from external circuits, which determines the gain of the cascade and its linearity. After amplification, the vertical ramp signal is fed to the output stage. At the output of the output stage (pin 3), a deviation current is formed. To power the output stage during the reverse stroke, a voltage booster circuit with a built-in diode and an external capacitor is used (pins 5 and 6). The voltage booster circuit is controlled by output pulses through the pin. 4 microcircuits. The built-in vertical alignment circuit is used to adjust the alignment. Centering is carried out by changing the constant level potential on pin 2. The characteristics of the microcircuit are given in table. 5.

2. Chips from SGS THOMSON

2.1. TDA1771

The TDA1771 chip is used in televisions and monitors as a vertical scanning output stage. The microcircuit is available in a SIP10 package. The location of the microcircuit pins is shown in Fig. 12. The microcircuit includes a sawtooth signal driver, an output amplifier, a voltage booster circuit for generating a reverse pulse, and a thermal protection circuit. The block diagram of the microcircuit is shown in Fig. 13.

The frame synchronization signal of negative polarity is supplied to the frame saw driver (pin 3). To pin. 6, a driver capacitor is connected, and the signal amplitude at the output of the driver is regulated using a circuit connected to the pin. 4. Generated sawtooth signal through the buffer stage and pin. 7 and 8 are fed to the vertical scanning signal amplifier. The same amplifier input receives a feedback signal that determines the gain and linearity of the output stage. The other input of the amplifier (direct) is supplied with a reference voltage from the internal voltage regulator. A deflection current is generated at the output of the amplifier (pin 1). To power the output stage of the amplifier during reverse stroke, a voltage boost circuit with an external capacitor and a diode is used. The characteristics of the microcircuit are given in table. 6.

2.2. TDA8174, TDA8174W

Chips TDA8174, TDA8174W, TDA8174A are used as a frame scan output stage in TVs and monitors. The microcircuits are produced in MULTIWATT11 and CLIPWATT11 packages, respectively. The location of the microcircuit pins is shown in Fig. 14 and 15. The microcircuits include a sawtooth signal driver, an output amplifier, a voltage booster circuit for generating a reverse pulse, and a thermal protection circuit. The block diagram of the microcircuit is shown in Fig. 16.

The frame synchronization signal of negative polarity is supplied to the frame saw driver (pin 3). To pin. 7, a driver capacitor is connected, and the signal amplitude at the output of the driver is regulated using a circuit connected to the pin. 4. Generated sawtooth signal through the buffer stage and pin. 8 and 9 are fed to the vertical scanning signal amplifier. The same pin receives a feedback signal that determines the gain and linearity of the output stage. The other input of the amplifier (direct) is supplied with a reference voltage from the internal voltage regulator. A deflection current is generated at the output of the amplifier (pin 1). To power the output stage of the amplifier during reverse stroke, a voltage boost circuit with an external capacitor and a diode is used. The characteristics of the microcircuit are given in table. 7.

2.3. Functional features of SGS THOMSON microcircuits

As a sawtooth signal shaper in SGS THOMSON microcircuits, a shaper is used, the diagram of which is shown in Fig. 17. The sawtooth signal is obtained by charging the external capacitor C with a constant current of the internal current source Ix. The sawtooth signal generated on the capacitor is fed through a buffer stage to the input of the vertical scanning signal amplifier of the microcircuit. The buffer stage has a low output impedance. While charging the capacitor, the voltage at the output of the buffer stage increases until the T1 switch, controlled by frame synchronization pulses, is closed. After closing the key, the capacitor is quickly discharged. When the voltage level Umin is reached at the output of the buffer stage, the switch opens and the charging process is repeated. The signal amplitude is adjusted by changing the value of the capacitor charging current.

The powerful output stage of the microcircuit is designed to generate deflection current in the frame coils with values ​​from 1 to 3 A and reverse voltage up to 60 V. Typical scheme The output stage is shown in Fig. 18. The output stage works as follows. During the first part of the sweep period is open power transistor Q2 and current flows through it from the power supply to the OS frame coils. In the second half of the sweep period, the energy accumulated in the frame coils forms a reverse current flowing from the frame coils through the open transistor Q8. To maintain a high level of the flyback pulse at the output of the amplifier, transistor Q8 is blocked by transistor Q7 for the duration of the flyback sweep.

To reduce the return stroke time, the voltage on the frame coils during the beam return period must be greater than the voltage during sweep. The supply voltage of the output stage is increased during the reverse stroke using a reverse driver.

A typical circuit of a reverse drive driver is shown in Fig. 18. The shape of the current through the frame coils and the voltage on them during the frame scanning process are shown in Fig. 19. During the sweep period (see Fig. 19, t6 - t7) transistors Q3, Q4 and Q5 of the driver are closed, and transistor Q6 is in saturation (Fig. 20) In this case, current flows from the power source through DB, CB and Q6 to case, charging the capacitor CB to the value UCB = US - UDB - UQ6(us). At the end of this period, the current reaches a peak value, after which it changes sign and then flows from the frame coils to the output stage. At the same time, the voltage on the frame coils UA reaches a minimum value.

At the beginning of the formation of the reverse stroke (see Fig. 19 t0 - t1), the transistor of the output stage Q8, which was previously in saturation, closes and the current generated by the energy accumulated in the frame coils flows through the damping circuit and elements D1, CB and Q6 . The path of current flow is illustrated in Fig. 21. When the voltage at point A exceeds the US value (see Fig. 19, t1 - t2), transistor Q3 opens and transistors Q4 and Q5 go into saturation. As a result, transistor Q6 closes. During this period, the voltage at point D reaches the value UD = US - UQ4(us). Thus, the voltage at point B (output stage supply voltage) becomes:

UB = UCB + UD or
UB = UCB + US – UQ4(us).

After reaching the voltage UD = US - UQ4(us) at point D, transistor Q4 closes and at time t2 - t3 energy is returned due to the flow of current from the frame coils through D1, CB and D2 to the power source (see Fig. 22) . The flowing current charges the capacitor CB. At time t3-t4, the current flowing through the frame coils drops to zero, and diode D1 closes. After the transistor of the output stage Q2, based on a signal from the buffer stage, goes into saturation (time t4 - t5), transistors Q3 and Q4 open. As a result, current from the power supply begins to flow through the frame coils through Q4, CB and Q2. The supply voltage at the collector of Q2 is UB = UCB + US - UQ4(us), i.e. almost double the power supply value. The flow of current is illustrated in Fig. 23.

This process continues until the signal from the buffer stage closes transistor Q2 of the output stage. When the voltage at point A reaches the value of the supply voltage US (see Fig. 19, t5 - t6), the reverse generator is blocked. In this case, transistor Q3 closes and closes transistor Q4, which makes the connection between point D and C (US). Therefore, UB is reduced to the value UB = US - UDB.

3. Chips from PHILIPS

3.1. TDA8354Q

The TDA8354Q chip is a vertical scan output stage circuit for use in televisions with 90 and 110° deflection systems. The bridge output stage of the microcircuit allows you to process input signal frequencies from 25 to 200 Hz, as well as use deflection coils for picture tubes with an aspect ratio of 4:3 and 16:9. The microcircuit is available in DIL13 and SIL13 packages. The location of the microcircuit pins is shown in Fig. 24. The block diagram is shown in Fig. 25. The chip uses a combined technology of Bipolar, CMOS and DMOS.

Output stages as standard require connecting the frame deflection coils through an expensive electrolytic capacitor with a capacity of about 2200 µF, which prevents leakage direct current through frame reels. However, in addition to more high price, the coupling capacitor causes the image to jump when switching channels. The TDA8354Q's bridged output stage allows the vertical deflection coils to be connected directly to amplifier outputs without a coupling capacitor, eliminating the above-mentioned bouncing and also making it easier to stabilize the vertical image position by controlling a small DC current.

The frame deflection coils are connected to the antiphase outputs of the output stage (pins 9 and 5) in series with the measuring resistor RM. The voltage across this resistor is proportional to the current flowing. To stabilize the amplitude of the output current, negative feedback is used (Fig. 25). The feedback voltage is removed from the resistor RM and through the resistor RCON connected in series with it, it is supplied to the input of the voltage/current converter. The output signal of the converter is fed to the input of output amplifier A of the bridge circuit. The values ​​of resistors RM and RCON determine the gain of the output stage of the microcircuit. By changing the values ​​of these resistors, you can set the output current value from 0.5 to 3.2 A.

To power the microcircuit during reverse motion, an additional UFLB power supply is used (pin 7). Connection of additional voltage during the reverse stroke is carried out by an internal switch. The absence of a coupling capacitor allows this voltage to be directly applied to the frame coils.

The reverse switch turns off when the output current reaches the set value. The output current is generated by stage A. The output voltage is reduced to the level of the main supply voltage.

The microcircuit's protection circuit is used to generate a protection signal in the event of a frame scanning malfunction to prevent burnout of the kinescope phosphor. The protection circuit also generates an image blanking signal (pin 1) during flyback, which can be used in conjunction with the SC (sandcastle) signal to synchronize the video processor. The protection circuit generates an active high level at the pin. 1 during the return period, and also in the following cases:

- the circuit of the personnel deflection coils is open (idle);

the feedback circuit is open;

lack of sweep signal;

activation of thermal protection (T=170°C);

pin closure 5 or 9 per power supply bus;

pin closure 5 or 9 per common conductor;

closing the input pins. 11 or 12 per power supply bus;

closing the input pins. 11 or 12 per common conductor;

- short circuit in deflection coils.

If there is no sweep signal or short circuit in the frame coils, the protection signal is generated with a delay of about 120 ms. This is necessary when working with signals of a minimum frequency of 25 Hz to correctly detect and fix the reverse signal.

In parallel with the deflection coils, a damping resistor RP is included to limit the oscillatory process in the frame coils. The current flowing through this resistor in the sweep and reverse modes has a different value. In this case, the current flowing through the measuring resistor RM consists of the current flowing through the resistor RP and the current flowing through the frame coils. This results in a decrease in the current flowing through them at the beginning of the sweep process. To compensate over time for the change in current flowing through the measuring resistor caused by the current through the damping resistor, an external compensating resistor Rcomp is used, connected to the output of the compensation circuit (pin 13) and the output of amplifier A (pin 9).

The input amplifier of the TDA8354Q chip is designed to work with synchroprocessors that generate a differential sawtooth vertical scan signal with a reference level DC voltage. The signal from the output of the amplifier is fed to one of the inputs of the voltage/current converter (Fig. 26). The feedback signal received through the resistor RCON (pin 3) comes to the same input of the converter. The voltage taken from the measuring resistor RM is applied to the other terminal of the converter through resistor RS. The output signal of the converter is proportional to the voltage applied to the inputs of the converter. Thus, with a closed feedback circuit, the device tends to equalize the potential at the pin. 2 microcircuits in relation to the potential on the pin. 3.

The output stage of the microcircuit consists of two identical amplifiers connected in a bridge circuit (Fig. 27). The frame deflection coils and the measuring resistor are connected to the outputs of the amplifiers (pins 9 and 5). In the first part of the vertical scanning period, a sawtooth current flows through transistor Q2, diode D3, vertical coils, measuring resistor RM and transistor Q5. In this case, power is supplied through the pin. 10 chips. The current flowing through the frame coils, which is maximum at the beginning of the period, will decrease linearly as the beam approaches the middle of the screen. In the second part of the sweep period, current flows through transistor Q4, measuring resistor RM, frame coils and transistor Q3. In this case, power is supplied from the same source, but through the pin. 4. In this case, the current flowing through the frame coils changes direction and increases linearly towards the end of the sweep period. The operation of the output stage during the sweep period is illustrated in Fig. 28.

During the reverse stroke, the current flowing through the frame coils must change from a minimum to a maximum value in a short time. Power during reverse stroke is supplied from the pin. 7 through the reverse switch - transistor Q1. To decouple the two power supplies, diodes D2 and D3 are additionally included in the output stages of the microcircuit.

The formation of the reverse current is carried out in two stages. At the first stage (1), the current, due to the energy accumulated in the frame coils, flows from the power source (pin 4) through transistor Q4, measuring resistor RM, frame coils, diode D1 and the reverse power circuit capacitor (see Fig. 27 ). In this case, the capacitor is charged with voltage at the pin. 9. Maximum voltage per pin. 9 will be 2 V greater than the flyback supply voltage. The operation of the output stage during the reverse sweep period is illustrated in Fig. 29.

The second stage of flyback formation begins from the moment when the current flowing through the frame coils passes through the zero level. The current through the frame coils then flows from the reverse source (pin 7), transistor Q1, diode D2, frame coils, measuring resistor RM, transistor Q5. Due to the voltage drop across transistor Q1 and diode D2, the voltage at the pin. 9 will be 2...8 V less than the power supply voltage. The current through the frame coils increases to a value corresponding to the input signal level. After this, transistor Q1 turns off and a new sweep cycle begins.

3.2 TDA8356

The TDA8356 vertical scan output stage chip is designed for use in televisions with 90 and 110 degree deflection systems. The bridged output stage of the microcircuit allows the use of scanning signals with frequencies from 50 to 120 Hz. The microcircuit is available in a SIL9P package. The location of the microcircuit pins is shown in Fig. 30. The block diagram of the microcircuit is shown in Fig. 31.

The input stage of the microcircuit is designed to work with synchroprocessors that generate a differential sawtooth vertical signal sent to the pin. 1 and 2. In this case, the reference DC voltage level is formed by the reference voltage source of the microcircuit. An external resistor RCON connected between the two differential inputs determines the current through the frame deflection coils. The dependence of the output current on the input current is defined as:

IinґRCON = IoutґRM, where Iout is the current through the frame deflection coils.

The maximum peak-to-peak input voltage amplitude is 1.8 V (1.5 V typical). The output bridge circuit allows you to connect frame deflection coils directly to the outputs of the amplification stages (pins 7 and 4). To control the current flowing through the frame coils, a resistor RM is connected in series with them. The voltage generated across this resistor through the pin. 9 of the microcircuit is supplied to a feedback signal amplifier, which limits the value of the output current. By changing the RM value, you can set the maximum output current value from 0.5 to 2 A.

To power the output stage during reverse stroke, a separate source with increased voltage is used (pin 6). The absence of a separating capacitor in the output circuits allows for more efficient use of this voltage, since all this voltage will be directly applied to the personnel deflection coils during the reverse stroke.

The microcircuit has a number of protective functions. To provide safe work output stage is:

Thermal protection;

Defence from short circuit between pin 4 and 7;

Short circuit protection for power supplies.

To blank the kinescope, a signal is generated by the built-in blanking circuit in the following cases:

During reverse frame scanning;

In case of a short circuit between pins. 4 and 7 or power supplies to the case;

When the feedback circuit is open;

When thermal protection is activated.

The main parameters of the microcircuit are given in table. 8.

3.3 TDA8357

The TDA8357 chip is designed for use in televisions with deflection systems of 90 and 110 degrees. The bridge output stage of the microcircuit allows the use of the microcircuit with signal frequencies from 25 to 200 Hz, as well as the use of deflection coils for picture tubes with an aspect ratio of 4:3 and 16:9. The microcircuit is available in a DBS9 package. The location of the microcircuit pins is shown in Fig. 32, and its block diagram is shown in Fig. 33. The chip uses a combined technology of Bipolar, CMOS and DMOS.

The input stage of the microcircuit is designed to work with synchroprocessors that generate a differential sawtooth vertical scan signal with a reference DC voltage level. In this case, the dependence of the output current on the input current is defined as:

2ґIinґRin=IoutґRM, where Iout is the current through the frame deflection coils.

The maximum peak-to-peak input voltage amplitude is 1.6 V.

The frame deflection coils, connected in series with the measuring resistor RM, are connected to the antiphase outputs of the output stage (pins 7 and 4). Negative feedback is used to stabilize the output current amplitude. The feedback voltage is removed from the resistor RM and through the resistor RS is supplied to the input of the voltage/current converter, the output signal of which is fed to the input of the output amplifier of the bridge circuit. The values ​​of resistors RM and RS determine the gain of the output stage of the microcircuit. By changing the values ​​of these resistors, you can set the output current value from 0.5 to 2 A.

In parallel with the deflection coils, a damping resistor RP is connected, limiting the oscillatory process in the frame coils. The currents flowing through this resistor during forward and reverse strokes have different values. The current flowing through the sense resistor RM consists of the current through the resistor RP and the current flowing through the frame coils. To compensate for the change in current flowing through the sense resistor caused by the different currents through the snubber resistor at the beginning and end of the sweep process, an external compensating resistor Rcomp is used. An external compensating resistor is connected between the pins. 7 and 1. In this case, the source of compensation current is a constant reference voltage at the pin. 1. To prevent the output voltage from influencing the input circuit, a diode is connected in series with the resistor.

To power the microcircuit during reverse motion, an additional VFB power supply (pin 6) is used. The connection of this voltage during the reverse stroke is carried out by an internal switch. The absence of a coupling capacitor allows this voltage to be directly applied to the frame coils. The reverse switch closes when the output current reaches the set value.

The microcircuit's protection circuit is used to block the output stage of the microcircuit when thermal protection is triggered and the output stage is overloaded. The microcircuit's protection circuit generates an image blanking signal (pin 8), which can be used together with the SC (sandcastle) signal to synchronize the video processor. Active high level on pin. 8 is formed during the reverse period, if the feedback circuit is open and when thermal protection is activated (T = 170°C).

The main parameters of the microcircuit are given in table. 9.

3.4 TDA8358

The TDA8358 chip is intended for use in televisions with deflection systems of 90 and 110 degrees as a vertical scanning output stage and an amplifier for geometric distortion correction signals. The bridge output stage of the microcircuit allows the use of the microcircuit with signal frequencies from 25 to 200 Hz, as well as the use of deflection coils for picture tubes with an aspect ratio of 4:3 and 16:9. The microcircuit is available in a DBS13 package. The location of the microcircuit pins is shown in Fig. 34, and its block diagram is shown in Fig. 35. The microcircuit is made using a combined Bipolar, CMOS and DMOS technology.

The chip contains a scanning unit similar to the TDA8357J. The difference is the presence of a compensation circuit that generates a voltage for the compensation resistor Rcomp. In addition, the microcircuit includes a signal amplifier for correcting geometric distortions. The correction signal amplifier is designed to amplify the correction current and directly control the diode modulator of the horizontal scan output stage circuit. For normal operation, the amplifier must have negative feedback. The feedback circuit is connected between the output and input terminals of the amplifier. The maximum voltage at the amplifier output should not exceed 68 V, and the maximum output current should not exceed 750 mA.

The main parameters of the microcircuit are given in table. 10.

4. Chips from TOSHIBA

4.1 TA8403K, TA8427K

The TA8403K and TA8427K microcircuits are used as a frame scanning output stage in TVs with a maximum deflection current in the frame coils of picture tubes of no more than 1.8 and 2.2 A (for TA8427K). The microcircuits are produced in the HSIP7 package. The location of the microcircuit pins is shown in Fig. 36. The microcircuits include preliminary and output amplifiers and a voltage booster circuit for generating reverse pulses. The block diagram of the microcircuits is shown in Fig. 37.

The vertical scan signal is supplied to the input of the pre-amplifier (pin 4) and, after amplification, is supplied to the output stage, where a deflection current is generated (pin 2). To power the output stage, a voltage booster circuit with an external capacitor and a diode is used. During forward stroke, the output stage is powered through an external diode with the voltage supplied to the pin. 6 microcircuits. During reverse stroke, the voltage accumulated on the external boost capacitor is added to the supply voltage using the reverse pulse generation circuit. This voltage is supplied to the pin. 3 microcircuits. In this case, reverse pulses are formed at the output of the cascade, exceeding in amplitude the supply voltage of the microcircuit. The main characteristics of the microcircuits are given in table. 11 (values ​​for the TA8427K chip are shown in brackets).

4.2 TA8432K

The TA8432K chip is a vertical scanning output stage with the formation of a vertical saw signal. The microcircuit is produced in the HSIP12 package and is used in televisions with a maximum deflection current in the frame coils of picture tubes of no more than 2.2 A. The location of the microcircuit pins is shown in Fig. 38. The microcircuit includes: an input trigger, a sawtooth signal driver, an output amplifier and a reverse pulse generation circuit.

The block diagram of the microcircuit is shown in Fig. 39.

Frame synchronization pulses are supplied to the input of the trigger (pin 2), the output of which is connected to the sawtooth signal shaper. The formation of a sawtooth signal is carried out using an external capacitor connected to the pin. 5. The amplitude of the frame saw signal is changed using a circuit connected to the pin. 3 microcircuits. The generated frame saw signal is sent to preamplifier, while the gain and linearity of the cascade depend on the feedback signal arriving at the pin. 6 microcircuits. The output stage directly generates the deflection current (pin 11). To power the output stage, a voltage booster circuit with an external capacitor and a diode is used. During forward stroke, the output stage is powered through an external diode with the voltage supplied to the pin. 7 microcircuits. During reverse stroke, the voltage accumulated on the external boost capacitor is added to the supply voltage using the reverse pulse generation circuit. As a result, approximately double the voltage is applied to the output stage of the microcircuit. In this case, reverse pulses are formed at the output of the cascade, exceeding in amplitude the supply voltage of the microcircuit. The main characteristics of the microcircuit are given in table. 12.

4.3 TA8445K

The TA8445K chip is similar to the TA8432K chip in its characteristics and scope of application. Distinctive feature is that a switching unit of size 50/60 Hz is additionally introduced into this microcircuit. The switching signal is supplied to the pin. 4 microcircuits. The block diagram of the microcircuit is shown in Fig. 40.

Integrated circuits BA511, BA521 and BA532 from Rohm are made in SIP1 packages with 10 pins and are low-frequency power amplifiers with identical circuits and different parameters. Designed for use in tape recorders, electrophones, television and radio receivers, and other middle-class audio equipment. The microcircuits have built-in output protection against short circuits in the load and thermal protection. To obtain maximum output power, the microcircuit must be installed on a heat sink (radiator). Some of the main parameters of the microcircuits are as follows:

Pout(13V/4Ω)
Kg(Pout.=0.2W,f=1KHz)

VA516, VA526, VA527, VA546

Integrated circuits BA516, BA526, BA527 and BA546 from Rohm are made in SIL packages with 9 pins and are low-frequency power amplifiers with identical circuits (pinouts) and different parameters. Designed for use in tape recorders, electrophones, television and radio receivers, and other middle-class battery-powered audio equipment. The microcircuits have built-in output protection against short circuits in the load and thermal protection. To obtain maximum power output, there is no need for a heat sink (heatsink). Some of the main parameters of the microcircuits are as follows:

Kg(Pout.=0.1W,f=1KHz)

VA5302A, VA5304

Integrated circuits BA5302A and BA5304 from Rohm are made in TABS7 packages with 12 pins and are two-channel low-frequency power amplifiers with identical circuits (pinouts) and different parameters. Designed for use in tape recorders, electrophones, television and radio receivers, and other middle-class audio equipment. Some of the main parameters of the microcircuits (output parameters for one channel) are as follows:

Kg(Pout.=0.2W,f=1KHz)

DBL1034-A, KA2206, KA22061, LA4180, LA4182, LA4183, LA4190, LA4192, LA4550, LA4555, LA4558

Integrated circuits DBL1034-A (Gold Star), KA2206 and KA22061 (Samsung), LA4180, LA4182, LA4183, LA4190, LA4192, LA4550, LA4555 and LA4558 (Sanyo) with identical circuits and different parameters are made in TABS7 packages with 12 pins. They are two-channel low-frequency power amplifiers and are intended for use in tape recorders, electrophones, television and radio receivers, and other middle-class audio equipment. To obtain double the output power at the same load resistance, with the same supply voltage, the microcircuits can be connected in a bridge circuit. Some of the main parameters of the microcircuits (output parameters for one channel) are as follows:

The microcircuits have built-in output protection against short circuits in the load and thermal protection. To obtain maximum output power, the microcircuit must be installed on a heat sink (radiator).

ESM432C, ESM532C, ESM632C, ESM732C, ESM1432C, ESM1532C, ESM1632C, ESM1732C, TDA1111SP

The listed integrated circuits from Thomson are made in SIP2 packages with 14 pins and are low-frequency power amplifiers with identical circuits (pinouts) and different parameters. Designed for use in tape recorders, electrophones, television and radio receivers, and other high-end audio equipment with bipolar power supply. Some of the main parameters of the microcircuits are as follows:

NA1350, NA1370

Integrated circuits HA1350 and HA1370 from Hitachi are made in SIP4 packages with 10 pins and are low-frequency power amplifiers. Designed for use in tape recorders, electrophones, television and radio receivers, and other middle-class audio equipment with bipolar (unbalanced) power supply. Some of the main parameters of the microcircuits are as follows:

The microcircuits have built-in output protection against short circuits in the load. To obtain maximum output power, the microcircuit must be installed on a heat sink (radiator).

NA1371

The HA1371 integrated circuit from Hitachi is housed in a TABS7 package with 12 pins and is a low-frequency power amplifier designed using a bridge circuit. Designed for use in car cassette recorders and middle-class electrophones. Some of the main parameters of the chip are as follows: Uccnom

Pout(9V/4Ω)
Kg(Pout.=1W,f=1KHz)

The microcircuit has built-in output protection against short circuit in the load. To obtain maximum output power, the microcircuit must be installed on a heat sink (radiator).

AT 13001

The HA13001 integrated circuit from Hitachi is housed in a SIP1 package with 12 pins and is a two-channel (stereo) low-frequency power amplifier. Designed for use in tape recorders, electrophones, television and radio receivers, and other middle-class audio equipment. The microcircuit has built-in output protection against short circuit in the load and thermal protection. To obtain maximum output power, the microcircuit must be installed on a heat sink (radiator). Some of the main parameters of the chip (output parameters for one channel) are as follows:

Pout(13V/4Ω)
Kg(Pout.=0.5W,f=1KHz)

NA13119

The HA13119 integrated circuit from Hitachi is housed in a SIP3 package with 15 pins and is a two-channel (stereo) low-frequency power amplifier. Designed for use in tape recorders, electrophones, television and radio receivers, and other middle-class audio equipment. The microcircuit has built-in output protection against short circuit in the load and thermal protection. To obtain maximum output power, the microcircuit must be installed on a heat sink (radiator). Some of the main parameters of the chip (output parameters for one channel) are as follows:

Pout(13V/4Ω)
Kg(Pout.=0.5W,f=1KHz)

KA22062, KIA6283, TA7233P, TA7283AP

Integrated circuits KA22062 and KIA6283 (Samsung), TA7233P and TA7283AP (Toshiba) with identical circuits and parameters are made in SIP4 packages with 12 pins and are two-channel low-frequency power amplifiers. Designed for use in cassette recorders, electrophones, radio and television receivers, and other middle-class audio equipment. Some of the main parameters of the microcircuits (output parameters for one channel) are as follows:

Pout(13V/4Ω)
Kg(Pout.=0.1W,f=1KHz)

Fig. 1 Location and pin assignment of the LA7845 chip

The LA7845 microcircuit is used as a vertical scanning output stage in televisions and monitors with picture tube diagonals of 33...37 inches and a maximum deflection current of 2.2 A.

The microcircuit is available in a SIP7H package.

The location of the microcircuit pins is shown in Fig. 1. The microcircuit includes an output amplifier, a voltage booster circuit for generating a reverse pulse, and a thermal protection circuit. The block diagram of the microcircuit is shown in Fig. 2.

Rice. 2. Block diagram of the LA7845 chip

The frame saw signal is supplied to the input of the frame scan signal amplifier, pin 5 of the microcircuit. The same pin receives a feedback signal that determines the gain and linearity of the cascade. The other input of the amplifier, pin 4, is supplied with a reference voltage. At the output of the amplifier, pin 2 of the microcircuit, a deflection current is formed. To power the output stage of the amplifier during reverse stroke, a voltage boost circuit with an external capacitor and a diode is used.

Main characteristics of the LA7845 chip

Parameter	Meaning
Maximum supply voltage Vcc	40 V
Maximum output stage supply voltage VH	85 V
Supply voltage Vcc	10...38 V
Supply voltage Vcc (typical value)	24 V
Maximum output deflection current	2.2 A