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(7) Example of Changing the Temperature Gradient with an External Temperature Sensor (Thermistor)
The S1F76640, which is equipped with the temperature gradient selection circuit in the stabilizer, enables
you to select three types of temperature gradients (-0.30%/°C, -0.40%/°C, and -0.50%/°C) as V
If other temperature gradients are required, as shown in Fig.8.18, connect a thermistor to resistor R
output voltage adjustment) in series; you can change the temperature gradient to any value.
(For pins 3 and 4, select a lower temperature gradient than the one to be changed from Table 5.1.)
10
8
6
4
2
0
-2
-4
-6
-8
-10
0
Note 1: The relationship between R
R
PV
V
=
REG
Using a thermistor as R
Note 2: The temperature characteristics of the thermistor indicate the nonlinearity; however, connecting resistor
R
to the thermistor in parallel changes nonlinear characteristics to linear characteristics.
P
S1F76640 Technical Manual (Rev.1.5)
V
REG
Note 2
R
R
T
P
R2
R
RV
1MΩ
R1
V
SS
R
OSC
1MΩ
V
DD
Fig.8.18 Temperature Gradient Change Example
Thermistor used
Thermistor not used
10
20
30
40
Ta [°C]
Fig.8.19 Output Voltage - Temperature
and V
T
REG
+ R
T
R
V
R1
increases the temperature gradient for V
T
8. APPLIED CIRCUIT EXAMPLES
1
16
RV
VRI
2
V
V
15
REG
OUT
3
TC1
CAP3+
14
4
TC2
CAP2+
13
5
XP
CAP2−
12
OFF
V
CAP1+
11
6
SS
OSC1
CAP1−
10
7
8
OSC2
V
9
DD
[Measurement conditions]
V
: 5V
DD
V
: 0V
SS
R
: 1MΩ (set to V
RV
R
:
T
Temperature gradient: -0.3 %/°C
50
is indicated as follows:
EPSON
V
OUT
+
C4
10μF
−
C2
+
10μF
−
C3
+
10μF
−
C1
+
10μF
−
= 10 at 25°C)
REG
10kΩ (0°C/50°C Ratio 9.00)
.
REG
output.
REG
(for
RV
23
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