LG Prada KE850, Service Manual

Page: 37 / 173

3. TECHNICAL BRIEF
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Input ON is a power-on input for SM-POWER with 2 active high levels (see Figure 8). It might be
triggered by a push button or by the RTCOUT output of the S-GOLD device as well. To detect if the
push-button is pressed during system operation the logical level at pin ON or its change (if Bit 1 EION
in INTCTRL2 is asserted) is recorded in bit LON of the ISF register. If the high level of voltage at pin
ON does not reach VIHdet (Vbat-0.8 ~ Vbat-0.3) the above-mentioned bit won’t be set.
To support Remote power on function for factory mass production, applied an analog switch as
following figure. As monitoring the RPWRON(GPIO_109) and Key matrix KP_OUT(1) & KP_IN(5),
KE850 system recognize whether remote power on or End-key pushed
Remote Power On
100K
R218
VBAT
9 1
1B0
2
1B1
8
1S
6
2A
2B0
3
2B1
4
7
2S
GND
5
VCC
10 FSA2267AL10X
U204
1A
C224
0.1u
R217
100K
PWRON
RPWRON
C_RPWRON
VBAT
END
PWRON
R205 100K
R204
1K
220K
R201
Q201
2
3
1
2SC5585
470K R202
RTC_OUT
PWRON
KP_OUT1
KP_IN5
Figure 9 Remote power on and End-key power on circuit