3. Power saving / Mute / LED control.
IC301 pin17, pin21 are power saving control pin, the condition of power saving and mode change, pin16 will
change from Low to Hi and active Mute function.
Normal Active
Mute L H
SUS / PD H L (Power saving)
IC301 pin21ΰSUSαfunction as LED control, the mode is as listed:
Power on Power saving Over range freq.
Pin21 Hi Low Low
4. CS control (CS1 ~ CS3).
To count H-SYNC by the output frequency, then output the cumulating as listed:
Freq. CS1 CS2 CS3
< 30K 0 0 0
30K~34K 0 0 0
34K~36.5K 1 0 0
36.5K~41K 1 0 1
41K~45K 0 1 0
45K~52K 0 1 1
52K~62K 1 1 0
62K~ 71K 1 1 1
5. Key Control: IC301 pin37~pin40 function as DAC switch input to control OSD display function.
Pin37 : 2.
Pin38 : Ϧ.
Pin39 : ϯ.
Pin40 : 1.
6. I
2
C Bus.
IC301 have two groups I
2
C bus to control IC302 E
2
PROM , IC401, Auto aliment, IC601, IC603,
and IC604.
C. Deflection control.
1. Auto SYNC deflection control and B+ control circuit horizontal and vertical sync through IC401 TDA9113 transmit.
Deflection controller IC401 TDA9113:
1-1 The control O/P (V-position, H-position, V-size, H-size, Pincushion, Pin-Balance, Trapezoid, Parallelogram,
moire) are use I
2
C control.
1-2 SYNC input:
H-sync (pin1) (From IC301 pin34).
V-sync (pin2) (From IC301 pin33).
1.3 Output:
a. B
+
Driver (pin28).
b. H-Driver (pin26).
c. EW-Driver (pin24).
d. V-focus (pin32).
e. V-out (pin23).
1-4 Horizontal.
a. H-sync inputs through pin1, then take a HFLY pulse from FBT pin5 to IC401 for AFC to make pin26 H-Driver
output at the same time.
b. Pin6 and pin8 (C429, R471) control horizontal hold in range.
1-5 Vertical.
a. V-sync outputs from MCU IC301 pin32 to IC401 pin2, then than smite from pin23, pin13, to IC501 KA2142
pin7, pin10.
b. IC401 pin23, outputs to vertical hold in range is controlled by pin22 (C508).
1-6 B
+
control.
Take a pulse from FBT pin5 and accumulates to become a DC voltage via D423, C437, then transformed by
VR403 to a conjunction to IC401 pin15 (#5V) outputs pulse by pin28 via Q202 to boost converter circuit.
26
ViewSonic Corporation Confidential
-
Do Not Copy 70f+SB-3E
To Next Page
Loading...
Need help?
General
