This phase control IC is intended to control thyristors, triacs, and transistors. The trigger pulses can be shifted within a phase angle between 0 ˚ and 180 ˚. Typical applications include converter circuits, AC controllers and three-phase current controllers. | SIEMENS Phase Control IC TCA 785 Bipolar IC Features Reliable recognition of zero passage Large application scope May be used as zero point switch LSL compatible Three-phase operation possible 3 ICs Output current 250 mA Large ramp current range Wide temperature range P-DIP-16-1 Type Ordering Code Package TCA 785 Q67000-A2321 P-DIP-16-1 This phase control IC is intended to control thyristors triacs and transistors. The trigger pulses can be shifted within a phase angle between 0 and 180 . Typical applications include converter circuits AC controllers and three-phase current controllers. This IC replaces the previous types TCA 780 and TCA 780 D. IEP00356 Pin Configuration top view Pin Definitions and Functions Pin Symbol Function 1 GND Ground 2 Q2 Output 2 inverted 3 Q U Output U 4 Q2 Output 1 inverted 5 Vsync Synchronous voltage 6 I Inhibit 7 Q Z Output Z 8 V REF Stabilized voltage 9 R9 Ramp resistance 10 C10 Ramp capacitance 11 V11 Control voltage 12 C12 Pulse extension 13 L Long pulse 14 Q 1 Output 1 15 Q 2 Output 2 16 Vs Supply voltage Semiconductor Group 1 SIEMENS TCA 785 Functional Description The synchronization signal is obtained via a high-ohmic resistance from the line voltage voltage Vs . A zero voltage detector evaluates the zero passages and transfers them to the synchronization register. This synchronization register controls a ramp generator the capacitor C10 of which is charged by a constant current determined by fa . If the ramp voltage V10 exceeds the control voltage V11 triggering angle 9 a signal is processed to the logic. Dependent on the magnitude of the control voltage V11 the triggering angle 9 can be shifted within a phase angle of 0 to 180 . For every half wave a positive pulse of approx. 30 is duration appears at the outputs Q 1 and Q 2. The pulse duration can be prolonged up to 180 via a capacitor C12. If pin 12 is connected to ground pulses with a duration between 9 and 180 will result. Outputs Q 1 and Q 2 supply the inverse .
