M62255FP
4.9 V
To DOUT
3.7 V
2.5 V
1.2 V
1.3 V
0.3 V
3.1 V
2.8 V
2.5 V
2.2 V
1.9 V
Reference voltage
0.1 V
To DOUT
4 times amplifier
Input voltage
Figure 2 Description of Level Magnification
Output voltage of DOUT is fixed as follows;
VDOUT = (VIN – Vref) × 4 + Vref (V) …………….. (1)
VDOUT: Output voltage of DOUT
VIN:
Voltage of IN1 (or IN2, IN3, IN4)
Vref: Reference voltage for A/D converter
In figure 2 reference voltage is 2.5 V. When input voltage of IN1 (or IN2, IN3, IN4) is set at 2.8 V, the difference
between input voltage and reference voltage is 0.3 V. The difference voltage (0.3 V) multiplied by 4 is 1.2 V. 1.2 V
added to reference voltage (2.5 V) makes 3.7 V which is output voltage of VDOUT.
The range of output voltage of VDOUT is between 0 V and 5 V. So in figure 2 the range of input voltage of IN1 (or IN2,
IN3, IN4) is between 1.9 V and 3.1 V. (This range of input voltage is difference from selected reference voltage.)
REJ03F0245-0200 Rev.2.00 Sep 14, 2007
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