MCP3304-CI/SL Microchip Technology, MCP3304-CI/SL Datasheet - Page 21

• Manufacturer Part Number: MCP3304-CI/SL
• Description: IC ADC 13BIT 2.7V 4CH SPI 16SOIC
• Manufacturer: Microchip Technology

Specifications of MCP3304-CI/SL

• Package / Case: 16-SOIC (0.154", 3.90mm Width)
• Number Of Bits: 13
• Sampling Rate (per Second): 100k
• Data Interface: Serial, SPI™
• Number Of Converters: 1
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Architecture: SAR
• Conversion Rate: 100 KSPs
• Resolution: 12 bit
• Input Type: Voltage
• Snr: 80.02 dB
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: MCP3304CI/SL

Using an external operation amplifier on the input
allows for gain and also buffers the input signal from the
input to the ADC allowing for a higher source
impedance. This circuit is shown in
FIGURE 5-5:
for gain and also buffers the input from any high-
impedance sources.
This circuit shows that some headroom will be lost due
to the amplifier output not being able to swing all the
way to the rail. An example would be for an output
swing of 0V to 5V. This limitation can be overcome by
supplying a V
mode voltage. Using a 2.048V reference for the A/D
converter while biasing the input signal at 2.5V solves
the problem. This circuit is shown in
FIGURE 5-6:
amplifier output swing limitation.
© 2008 Microchip Technology Inc.
1 kΩ
1 kΩ
V
V
IN
IN
1 µF
1 µF
REF
10 kΩ
10 kΩ
MCP6021
MCP606
1 MΩ
1 MΩ
+
+
1 µF
-
-
1 µF
that is slightly less than the common
Adding an amplifier allows
Circuit solution to overcome
V
V
MCP1525
MCP1525
IN+
IN-
IN+
IN-
OUT
OUT
MCP330X
V
2.048V
MCP330X
V
REF
V
0.1 µF
Figure
0.1 µF
IN
Figure
IN
V
REF
V
V
0.1 µF
0.1 µF
DD
DD
5-5.
10 kΩ
5-5.
= 5V
= 5V
5.4
The common mode input range has no restriction and is
equal to the absolute input voltage range: V
V
mode voltage has a limited swing, if the entire range of
the A/D converter is to be used.
Figure 5-8
common mode voltage swing. A smaller V
wider flexibility in a common mode voltage. V
down to 400 mv, exhibit less than 0.1 LSB change in
DNL and INL. For characterization graphs that show
this performance relationship, see
Figure
FIGURE 5-7:
of Full Differential Input Signal versus V
FIGURE 5-8:
versus V
DD
-1
-1
5
4
3
2
1
0
0.25
+ 0.3V. However, for a given V
5
4
3
2
1
0
0.25
2-12.
Common Mode Input Range
REF
show the relationship between V
1.0
0.5
for Pseudo Differential Input.
MCP3302/04
Common Mode Input Range
Common Mode Input Range
V
V
REF
REF
2.5
1.25
4.05V
0.95V
4.05V
0.95V
(V)
(V)
DS21697E-page 21
REF
Figure 2-9
Figure 5-7
, the common
REF
4.0
2.0
V
V
REF
SS
DD
REF
REF
DD
allows for
-0.3V to
and the
= 5V
2.8V
2.3V
= 5V
2.8V
2.3V
.
levels,
5.0
2.5
and
and