Toshiba – Toshiba TMP87CP24AF User Manual
Page 102
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TOSHIBA
TMP87CM24A/P24A
Voltage Regulator for LCD Driver in TMP87CM24A/P24AF
Two phenomenon have been found that the Voltage Regulator for LCD Driver in TMP87CM24A/P24AF
behaved unexpectedly.
The phenomena(l) occurs underthe condithon.
During driving LCD by using LCD Driver. Power Supply Voltage(Vdd)falls down in very short period(i.e. less
than 1 msec.) and comes back within its operating voltage range.(please refer Figure 2-56)
Specification for the phenomena(l)
a) The "Falling time "should be longer than 1 msec within the range of an operating voltage
(at 2.2V to 5.5V,Торг = -10 to 70 X)
b) The "Fluctuation of Vdd"should be less than 0.7V,when falling time of Vdd is shorter than
1.msec(at Торг = -10 to 70X)
The
Voltage
Regulator
for
LCD
Driver
would
not
generate
proper
voltage
and/or
it
could
take
very
long
time
to
reach
the
proper
voltage.
Then
LCD
could
not
display
any
and/or
it
could
take
very
long
time
before displaying any on LCD module.
We have confirmed that the phenomenon(l) can be avoid under the following conditions,
(1) The Falling time is longer than 1 msec, within the range of an operating voltage
(2.2v througe 5.5v),this phenomena will not occur.
(2) The fluctuation of operating voltage is less than 0.7v with any falling time,this phenomena will
not occur.
3
-
24-102
2002
-
10-03