Datasheet

© 2008 Microchip Technology Inc. DS21295D-page 15
MCP3004/3008
3.0 PIN DESCRIPTIONS
The descriptions of the pins are listed in Tabl e 3- 1.
Additional descriptions of the device pins follows.
TABLE 3-1: PIN FUNCTION TABLE
3.1 Digital Ground (DGND)
Digital ground connection to internal digital circuitry.
3.2 Analog Ground (AGND)
Analog ground connection to internal analog circuitry.
3.3 Analog inputs (CH0 - CH7)
Analog inputs for channels 0 - 7, respectively, for the
multiplexed inputs. Each pair of channels can be
programmed to be used as two independent channels
in single-ended mode or as a single pseudo-differential
input where one channel is IN+ and one channel is IN.
See Section 4.1 “Analog Inputs”, “Analog Inputs”,
and Section 5.0 “Serial Communication”, “Serial
Communication”, for information on programming the
channel configuration.
3.4 Serial Clock (CLK)
The SPI clock pin is used to initiate a conversion and
clock out each bit of the conversion as it takes place.
See Section 6.2 “Maintaining Minimum Clock
Speed”, “Maintaining Minimum Clock Speed”, for
constraints on clock speed.
3.5 Serial Data Input (D
IN
)
The SPI port serial data input pin is used to load
channel configuration data into the device.
3.6 Serial Data Output (D
OUT
)
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.
3.7 Chip Select/Shutdown (CS/SHDN)
The CS/SHDN pin is used to initiate communication
with the device when pulled low. When pulled high, it
will end a conversion and put the device in low-power
standby. The CS
/SHDN pin must be pulled high
between conversions.
MCP3004 MCP3008
Symbol Description
PDIP, SOIC,
TSSOP
PDIP, SOIC
1 1 CH0 Analog Input
2 2 CH1 Analog Input
3 3 CH2 Analog Input
4 4 CH3 Analog Input
– 5 CH4 Analog Input
– 6 CH5 Analog Input
– 7 CH6 Analog Input
– 8 CH7 Analog Input
7 9 DGND Digital Ground
810CS
/SHDN Chip Select/Shutdown Input
911D
IN
Serial Data In
10 12 D
OUT
Serial Data Out
11 13 CLK Serial Clock
12 14 AGND Analog Ground
13 15 V
REF
Reference Voltage Input
14 16 V
DD
+2.7V to 5.5V Power Supply
5,6 – NC No Connection