6. FUNCTIONAL DESCRIPTION
S1D15722D01B000 Technical Manual (Rev.1.1)
EPSON
25
6.7.2 Precautions
(1) Noise
influence
The temperature sensor circuit operates in the SV22 voltage generated in the regulator operating in the V
DI
system which is IC’s logic operating voltage. The circuits of the SV22 voltage are configured so that steady
variations in the V
DI
power supply system do not have an effect on them. However, if logic is operated at high
speed for writing to RAM, for example, power supply noise may be caused in the V
DI
voltage and the SV22
voltage may also be influenced similarly.
To perform temperature detection accurately, be sure to stop access from the MPU when capturing the
temperature sensor output and comply with operating conditions specified at the AC timing.
(2) Influence
of
mounting
The temperature sensor circuit analog output SVD2 is specified using the output voltage value for the IC’s
board potential V
SS
. When measuring the SVD2 potential in the actual system, attention should be paid to the
relationship between the IC’s board potential and the system ground’s potential.
Fig.6.8 Influence of Resistance R between System Ground and V
SS
V
3
to MV
2
V
DD
V
DI
SV
22
IC’s board potential
=V
SSL
∆
V=
Σ
I
×
R
R
Σ
I
System ground
T
e
mper
at
ur
e
s
e
n
s
or c
ircui
t
SV
D2I
SV
22
generating
circuit
Lo
g
ic
di
s
p
lay
d
a
ta
RAM
V
DI
generating
circuit
P
o
w
e
r sup
p
ly
ci
rc
u
it
SV
D2
o
Содержание S1D15722 Series
Страница 1: ...Rev 1 1 S1D15722D01B000 Technical Manual ...