w925e625 ETC-unknow, w925e625 Datasheet - Page 56

• Manufacturer Part Number: w925e625
• Description: 8-bit Cid Microcontroller
• Manufacturer: ETC-unknow

Input Pre-Processor
The input signal is processed by Input Pre-Processor, which is comprised of two OP amps and a bias
source(VREF). The gain OP-amps are used to bias the input voltage with the VREF signal voltage.
VREF is V
adjustable OP amps are sued to select the input gain by connecting a feedback resistor between
GCFB and INN pins. Figure 6-19 shows the differential input configuration and Figure 6-20 shows the
single-ended configuration.
AD
/2 typically, this pin is recommended to connect a 0.1 Uf capacitor to V
Differential Input Amplifier
C1 = C2
R1 = R2
R3 = (R4 R5) / (R4 + R5)
Figure 6-20 Single-Ended Input Gain Control Circuit
Figure 6-19 Differential Input Gain Control Circuit
C1
C2
22n
Voltage Gain
Av = R2 / R1
C
R1
R2
R1
R3
0.1uF
R4
R2
- 56 -
R5
0.1uF
Voltage Gain
Av = R5 / R1
Input Impedance
Zin = 2
GCFB
VREF
INN
INP
GCFB
VREF
INN
INP
+
-
+
-
R1 + (1 / wC)
2
2
W925E/C625
AS
. The gain