S-5855AACA-I4T1U Datasheet, PDF (13/27 Pages) Seiko Instruments Inc – PWM OUTPUT TEMPERATURE SENSOR IC

Rev.1.2_01
PWM OUTPUT TEMPERATURE SENSOR IC
S-5855A Series
 Operation
1. Duty ratio
The following equation is the definition of duty ratio.
Duty ratio = PW / T × 100 [%]
The definitions of PW and T are shown in Figure 11.
PW
T
Figure 11
2. Oscillation frequency
The oscillation frequency is set by the capacitance value of the capacitor CFREQ for the oscillation frequency.
The relationship between the CFREQ capacitance value of each duty ratio temperature sensitivity and the center value
of the oscillation frequency are shown in Table 11.
Duty ratio temperature sensitivity
Ddt(s) [%/°C]
−1
−2
−3
−4
Table 11
CFREQ capacitance value
[nF]
2.2
4.7
6.8
10.0
Center value of oscillation frequency
[Hz]
2300
2160
2240
2030
13