поискавой системы для электроныых деталей |
|
TDA1085C датащи(PDF) 5 Page - ON Semiconductor |
|
TDA1085C датащи(HTML) 5 Page - ON Semiconductor |
5 / 12 page TDA1085C http://onsemi.com 5 As the voltages applied by Pins 5 and 6 are derived from the internal voltage regulator supply and Pin 4 voltage is also derived from the same source, motor speed (which is determined by the ratios between above mentioned voltages) is totally independent from VCC variations and temperature factor. Control Amplifier (Pin 16) It amplifies the difference between true speed (Pin 4) and set speed (Pin 5), through the ramp generator. Its output available at Pin 16 is a double sense current source with a maximum capability of ± 100 mA and a specified transconductance (340 mA/V typical). Pin 16 drives directly the trigger pulse generator, and must be loaded by an electrical network which compensates the mechanical characteristics of the motor and its load, in order to provide stability in any condition and shortest transient response; see Figure 4. This network must be adjusted experimentally. In case of a periodic torque variations, Pin 16 directly provides the phase angle oscillations. Trigger Pulse Generator (Pins 1, 2, 5, 13, 14, 15) This circuit performs four functions: • The conversion of the control amplifier DC output level to a proportional firing angle at every main line half cycle. • The calibration of pulse duration. • The repetition of the pulse if the triac fails to latch on if the current has been interrupted by brush bounce. • The delay of firing pulse until the current crosses zero at wide firing angles and inductive loads. RPin 15 programs the Pin 14 discharging current. Saw tooth signal is then fully determined by R15 and C14 (usually 47 nF). Firing pulse duration and repetition period are in inverse ratio to the saw tooth slope. Pin 13 is the pulse output and an external limiting resistor is mandatory. Maximum current capability is 200 mA. Current Limiter (Pin 3) Safe operation of the motor and triac under all conditions is ensured by limiting the peak current. The motor current develops an alternative voltage in the shunt resistor (0.05 W in Figure 4). The negative half waves are transferred to Pin 3 which is positively preset at a voltage determined by resistors R3 and R4. As motor current increases, the dynamical voltage range of Pin 3 increases and when Pin 3 becomes slightly negative in respect to Pin 8, a current starts to circulate in it. This current, amplified typically 180 times, is then used to discharge Pin 7 capacitor and, as a result, reduces firing angle down to a value where an equilibrium is reached. The choice of resistors R3, R4 and shunt determines the magnitude of the discharge current signals on CPin 7. Notice that the current limiter acts only on peak triac current. APPLICATION NOTES (Refer to Figure 4) Printed Circuit Layout Rules In the common applications, where TDA 1085C is used, there is on the same board, presence of high voltage, high currents as well as low voltage signals where millivolts count. It is of first magnitude importance to separate them from each other and to respect the following rules: • Capacitor decoupling pins, which are the inputs of the same comparator, must be physically close to the IC, close to each other and grounded in the same point. • Ground connection for tachogenerator must be directly connected to Pin 8 and should ground only the tacho. In effect, the latter is a first magnitude noise generator due to its proximity to the motor which induces high d φ/dt signals. • The ground pattern must be in the “star style” in order to fully eliminate power currents flowing in the ground network devoted to capacitors decoupling sensitive Pins: 4, 5, 7, 11, 12, 14, 16. As an example, Figure 5 presents a PC board pattern which concerns the group of sensitive Pins and their associated capacitors into which the a.m. rules have been implemented. Notice the full separation of “Signal World” from “Power”, one by line AB and their communication by a unique strip. These rules will lead to much satisfactory volume production in the sense that speed adjustment will stay valid in the entire speed range. Power Supply As dropping resistor dissipates noticeable power, it is necessary to reduce the ICC needs down to a minimum. Triggering pulses, if a certain number of repetitions are kept in reserve to cope with motor brush wearing at the end of its life, are the largest ICC user. Classical worst case configuration has to be considered to select dropping resistor. In addition, the parallel regulator must be always into its dynamic range, i.e., IPin 10 over 1.0 mA and VPin 10 over 3.0 V in any extreme configuration. The double filtering cell is mandatory. |
Аналогичный номер детали - TDA1085C |
|
Аналогичное описание - TDA1085C |
|
|
ссылки URL |
Конфиденциальность |
ALLDATASHEETRU.COM |
Вашему бизинису помогли Аллдатащит? [ DONATE ] |
Что такое Аллдатащит | реклама | контакт | Конфиденциальность | обмен ссыками | поиск по производителю All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |