MCP3301T MICROCHIP [Microchip Technology], MCP3301T Datasheet - Page 13

• Manufacturer Part Number: MCP3301T
• Description: 13-Bit Differential Input, Low Power A/D Converter with SPI Serial Interface
• Manufacturer: MICROCHIP [Microchip Technology]

3.0
The descriptions of the pins are listed in
TABLE 3-1:
3.1
This input pin provides the reference voltage for the
device, which determines the maximum range of the
analog input signal and the LSB size.
The LSB size is determined by the equation shown
below. As the reference input is reduced, the LSB size
is reduced accordingly.
EQUATION
When using an external voltage reference device, the
system
manufacturer’s recommendations for circuit layout.
Any instability in the operation of the reference device
will have a direct effect on the accuracy of the ADC
conversion results.
3.2
This pin has an absolute voltage range of V
V
absolute value of (IN+) - (IN-).
3.3
This pin has an absolute voltage range of V
V
absolute value of (IN+) - (IN-).
3.4
If an analog ground plane is available, it is
recommended that this device be tied to the analog
ground plane in the circuit. See
Considerations”, for more information regarding
circuit layout.
 2011 Microchip Technology Inc.
DD
DD
MSOP, PDIP,
+0.3V. The full scale input range is defined as the
+0.3V. The full scale input range is defined as the
SOIC
1
2
3
4
5
6
7
8
PIN DESCRIPTIONS
Voltage Reference (V
Positive Analog Input (IN+)
Negative Analog Input (IN-)
Ground Connection (V
designer
LSB Size =
PIN FUNCTION TABLE
should
CS/SHDN
2 x V
Name
D
V
IN(+)
IN(-)
CLK
V
always
V
8192
REF
OUT
DD
SS
Section 5.6 “Layout
REF
REF
SS
refer
Table
)
)
SS
SS
Reference Voltage Input
Positive Analog Input
Ground
Chip Select / Shutdown Input
Serial Data Out
Serial Clock
+4.5V to 5.5V Power Supply
Negative Analog Input
3-1.
-0.3V to
-0.3V to
to
the
3.5
The CS/SHDN pin is used to initiate communication
with the device when pulled low. This pin will end a
conversion and put the device in low power standby
when pulled high. The CS/SHDN pin must be pulled
high between conversions and cannot be tied low for
multiple conversions. See
communication protocol.
3.6
The SPI serial data output pin is used to shift out the
results of the A/D conversion. Data will always change
on the falling edge of each clock as the conversion
takes place. See
protocol.
3.7
The SPI clock pin is used to initiate a conversion, as
well as to clock out each bit of the conversion as it takes
place. See
for constraints on clock speed, and
communication protocol.
3.8
The device can operate from 2.7V to 5.5V, but the
performance is applicable from a 4.5V to 5.5V supply
range. To ensure accuracy, a 0.1 µF ceramic bypass
capacitor should be placed as close as possible to the
pin. See
more information regarding circuit layout.
Chip Select/Shutdown (CS/SHDN)
Serial Data Output (D
Serial Clock (CLK)
Power Supply (V
Section 5.6 “Layout Considerations”
Section 5.2 “Driving the Analog Input”
Function
Figure 6-2
for serial communication
MCP3301
DD
Figure 6-2
)
Figure 6-2
DS21700D-page 13
OUT
)
for serial
for serial
for