TA8859 pillow calibration circuit

Relevant key device information applied in this article: TA8859 C1740 ISS133 field excitation pulse input. The field excitation pulse signal is directly added to pin (13) of N402 (TA8859) to trigger the internal monostable trigger and generate a field frequency pulse with constant pulse width. , after shaping, the field sawtooth wave forming circuit is controlled, so that the N402 (15) pin is connected to the external sawtooth wave forming capacitor C418 for constant current charging to form a sawtooth wave current. The amplitude and charging speed of the sawtooth wave are controlled by the N402's AGC circuit to meet the needs of 50Hz/60Hz. The sawtooth wave generated by the sawtooth wave forming circuit undergoes a series of linear corrections inside the N402, and then a field excitation pulse is output from pin (8). The parabolic voltage output by pin (2) of N402 (TA8859), after being amplified by V401 and V403, outputs a parabolic wave from the collector of V403 and sends it to the horizontal deflection coil, thereby changing the current flowing through the horizontal deflection coil, that is The correction of east/west pincushion distortion is completed. The correction amount of east/west pincushion distortion needs to enter the bus adjustment state and adjust the bus. Pin 1: 3.7V - High voltage stability detection input pin 2: 1.1V - Pin 3 of the parabolic wave output terminal of the East-West pillow calibration: 12.0V——+12V voltage input pin 4: 5.5V——Pin 5 of the feedback input terminal of the East-West pillow calibration: 0V——Pin 6 of the ground: 4.2V——Field scanning feedback input Terminal 7 pin: 0V - empty pin 8 pin: 2.1V - field sawtooth wave voltage output terminal 9 pin: 4.8V - bus data line connection terminal 10 pin: 4.8V - bus clock line connection terminal 11 pin: 0V ——Open pin 12: 0V — Ground pin 13: 4.4V — Field excitation pulse signal input terminal 14: 3.8V — Pulse shaping external filter terminal 15: 6.0V — Field scanning sawtooth wave voltage formation Terminal 16: 3.0V——Automatic gain control filter terminal