TA1276AFG Datasheet, PDF (37/83 Pages) Toshiba Semiconductor – PAL/NTSC Video Chroma And Deflection IC For CTV

TA1276AFG
Note
Parameter
Test Conditions (unless otherwise stated, V_CC1 = 5 V, V_CC2/V_CC3/DEF V_CC = 9 V, Ta = 25 ± 3°C)
Switching Mode
SW₁₅ SW₄₉ SW₅₀ SW₅₃
Test Conditions
1) Set the BUS control data to the preset value.
2) Set SW₅₀ to A (maximum gain), turn the Y mute off (1), and turn the black stretch gain off.
3) Connect pin 78 to an external power supply (PS), increase the voltage from V₅₃, and plot the resulting change in
voltage S₁ of pin 3.
4) Next, turn the black stretch gain on (0), set the black stretch point 1 to the minimum (000), increase the PS voltage
from V₅₃ as in 3), and plot the resulting change in voltage S₂ of pin 3.
5) Set the black stretch point 1 to the maximum (111), increase the PS voltage from V₅₃ as in 3), and plot the change in
voltage S₃ of pin 3.
6) Use the diagram below to calculate the intersections V_BST1 and V_BST2 of S₁, S₂, and S₃. Use the following formulas
to calculate P_BST1 and P_BST2.
P_BST1 [(IRE)] = ((V_BST1 [V] − V₄₉ [V] ÷ 1.4 [V]) × 100 [(IRE)]
P_BST2 [(IRE)] = ((V_BST2 [V] − V₄₉ [V] ÷ 1.4 [V]) × 100 [(IRE)]
V₃ Black Stretch Start Point (1)
C OFF A
C
Pin
V_BST2
S₃
S₁
V_BST1
S₂ (asymptotic line)
V₄₉
Pin
37
2002-04-01