User manual

MCP6H04 Evaluation Board User’s Guide
DS52005A-page 14 © 2011 Microchip Technology Inc.
2.3.1.4 INPUT STAGE
The input stage consists of two resistors and three capacitors. All three capacitors are
forming a noise filter. Figure 2-6 shows the circuit diagram of the input stage
(C
5
=C
6
=10nF, C
4
= 100 nF and R
5
=R
6
=1K).
FIGURE 2-6: Input Stage Block.
2.3.1.5 INPUT BUFFER BLOCK
The input buffer block consists of two op amps in buffer configuration with outputs tied
together through one resistor. Figure 2-7 shows the circuit diagram of the input buffer
block (R
F
=R
F
*=50K, R
G
=1K).
FIGURE 2-7: Input Buffer Block.
R
5
R
6
C
4
C
5
C
6
V
IN
(-)
V
IN
(+)
V
A
V
B
+
-
V
DD
V
OUT1
V
OUT2
+
-
V
DD
R
G
R
F
R
F
*
V
A
V
B