1 - 39
1.6.4
Reset circuit
< Selecting the reset voltage >
The operation power voltage range of the microcomputer (IC102) is 2.7V to 5.5V. Normally,
the voltage should be reset when the microcomputer power (M3_3V) drops to 2.7V or less, but
as the operation could malfunction due to power voltage noise, etc., the reset voltage is se-
lected so that resetting actually takes place at 2.1V or less.
< Selection of resistance constant >
According to the DC/DC converter design sheet, the M3_3V power voltage range is 3.3V to
3.5V. However, if the power voltage drops to 2.1V or less due to an error mode, the following
will be attained:
1+ (R146/R156) = reset voltage (2.1V) / reference voltage (1.25V).
Thus, R146=6.8k
Ω
and R156=10k
Ω
are used.
< Oscillation circuit >
With the specifications X100 (CP285P030A11), the clock is supplied to the microcomputer's pin
12 with a 10MHz oscillator. ASIC multiplies the microcomputer clock in the ASIC, and uses it
as the system clock.
+
-
1.25V
5
µ
A
25
µ
A
External delay capacitor : 103
6.8k
Ω
10k
Ω
M3_3V
M51957AFP
220
Ω
1.25V
1.96V
1k
Ω
M3_3V
9
1.96V
0.67V
Hi
Lo
Non-
specific
output
t
d
t
d
td = 0.34 x External capacitor (pF)
µ
Sec
= 0.34 x 10000
µ
Sec = 3.4msec
Output state
Power voltage (M3_3V)
R146
R156
IC101
Microcomputer
reset terminal
Summary of Contents for NEC MultiSync LCD1550X LCD1550X LCD1550X
Page 88: ...SCHEMATIC DIAGRAM POWER LCD1550X Normal Power Save 1ch Pin 4 2ch Pin 1 3ch Pin 2 4ch Pin 5...
Page 89: ...SCHEMATIC DIAGRAM PWB MAIN POWER LCD1550X...
Page 90: ...SCHEMATIC DIAGRAM PWB MAIN INPUT LCD1550X...
Page 91: ...SCHEMATIC DIAGRAM PWB MAIN SYNC LCD1550X...
Page 92: ...SCHEMATIC DIAGRAM PWB MAIN TMDS LCD1550X...
Page 96: ...SCHEMATIC DIAGRAM PWB MAIN ASIC LCD1550X...
Page 97: ...SCHEMATIC DIAGRAM INVERTER LCD1550X 1ch Q701 B 2ch Q702 B...
Page 98: ...SCHEMATIC DIAGRAM PWB SW LCD1550X...
Page 100: ...SCHEMATIC DIAGRAM POWER LCD1550X...
Page 101: ...SCHEMATIC DIAGRAM PWB MAIN POWER LCD1550X...
Page 102: ...SCHEMATIC DIAGRAM PWB MAIN INPUT LCD1550X...
Page 103: ...SCHEMATIC DIAGRAM PWB MAIN SYNC LCD1550X...
Page 104: ...SCHEMATIC DIAGRAM PWB MAIN TMDS LCD1550X...
Page 105: ...SCHEMATIC DIAGRAM PWB MAIN MC LCD1550X...
Page 106: ...SCHEMATIC DIAGRAM PWB MAIN ASIC LCD1550X...
Page 107: ...SCHEMATIC DIAGRAM INVERTER LCD1550X...
Page 108: ...SCHEMATIC DIAGRAM PWB SW LCD1550X...
Page 127: ...16 Document No VSPF A028 Bave Average brightness of 1 to 9 10 50 90 90 10 50 5 1 2 3 6 9 8 7 4...
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